Paraves Sereno, 1997
Definition- (Passer domesticus <- Oviraptor philoceratops) (Holtz and Osmolska, 2004; modified from Sereno, 1998)
= Troodontidae sensu Varricchio, 1997
Definition- (Troodon formosus, Saurornithoides mongoliensis, Borogovia gracilicrus, Sinornithoides youngi <- Ornithomimus velox, Oviraptor philoceratops)

Eumaniraptora Padian, Hutchinson and Holtz, 1997
Definition- (Deinonychus antirrhopus + Passer domesticus) (Maryanska et al., 2002; modified from Padian, Hutchinson and Holtz, 1999)
= Maniraptora sensu Padian and Holtz, 1995
Definition- (Dromaeosaurus albertensis + Passer domesticus)
= Deinonychosauria sensu Sereno, 1997
Definition- (Troodon formosus + Dromaeosaurus albertensis) (modified)
= Deinonychosauria sensu Sereno, 1998
Definition- (Troodon formosus + Velociraptor mongoliensis) (modified)
= Avialae sensu Gauthier and de Queiroz, 2001
Definition- (feathered wings homologous with Vultur gryphus and used for powered flight)
Comments- Xu et al. (1999) found Eumaniraptora to include Archaeopteryx, Rahonavis, Unenlagia and Dromaeosauridae. Troodontids were excluded, as they supposedly lacked
- horizontal ridge over ventral process of squamosal. This appears to be present in Saurornithoides and Troodon, though absent in Sinornithoides and perhaps Mei. Archaeopteryx was miscoded as having the structure however, when its presence in this taxon is uncertain. It is possibly convergent in derived troodontids and dromaeosaurids.
- twisted paroccipital processes (only in Xu et al., 1999). These are present in the basal troodontid IGM 100/1005, though absent in other troodontids. It may be a paravian synapomorphy reversed in derived troodontids.
- posterior temporal recess enters paroccipital process. This is present in Byronosaurus and Troodon, though absent in Mei, and was also miscoded as absent in tyrannosaurids, ornithomimids and oviraptorids. It's near certainly a tyrannoraptoran character reversed in Mei.
- glenoid faces laterally. This is present in Sinovenator and Troodon, though not Sinornithoides. It is probably a paravian synapomorphy reversed in Sinornithoides.
- coracoid forms sharp angle with scapula. Velociraptorines (e.g. Deinonychus, Velociraptor) also lack this, but were miscoded as unknown by Xu et al.. It may support placing troodontids outside Eumaniraptora, or may have convergently developed in microraptorians and birds.
- proximodistally elongate coracoid (only in Xu et al., 1999). This is present in Mei, Sinovenator and Sinornithoides, and was also miscoded as absent in oviraptorids. It is a maniraptoran synapomorphy.
- coracoid facets on sternals almost facing anteriorly. The angle is estimated at ~33 degrees from transverse in Sinornithoides, which is more than other maniraptorans except Caudipteryx, Citipati and one Ingenia specimen. It may be a reversal. Archaeopteryx was miscoded as having this character, which is unknown in the genus because the supposed sternum is actually a coracoid.
- ulna longer than metatarsus. This is a valid character for excluding troodontids from Eumaniraptora, though it seems artificial in the sense that arm length varies independently with foot length. Microraptor was miscoded as lacking the character.
- metacarpal III bowed laterally. This is present in Sinornithoides, but not the basal troodontids WDC DML 001 or IGM 100/1005. It was miscoded as absent in Compsognathus, ornithomimosaurs (present in Shenzhousaurus, absent in others), and as unknown Protarchaeopteryx.
- pubic peduncle anteroposteriorly longer than acetabulum. This is true in Sinovenator and Sinornithoides, and is a valid character for this topology.
- opisthopubic pelvis. This is present in Jinfengopteryx, Sinovenator and possibly embryonic Troodon, though absent in Sinornithoides and Saurornithoides. It may be a paravian synapomorphy reversed in derived troodontids.
- distal ischium mediolaterally compressed. This appears to be true for Sinovenator, Sinusonasus, Sinornithoides, Troodon, and probably Saurornithoides as well. It was also miscoded as absent in oviraptorids and is probably a maniraptoran synapomorphy.

Pedopenna Xu and Zhang, 2005
P. daohugouensis Xu and Zhang, 2005
Bathonian, Middle Jurassic
Daohugou Formation, Nei Mongol, China
Holotype- (IVPP V12721) (<1 m) distal tibia, distal fibula, tarsus, metatarsal I, phalanx I-1 (8.6 mm), pedal ungual I (~7.6 mm), metatarsal II (57.6 mm), phalanx II-1 (11.6 mm), phalanx II-2 (14.2 mm), pedal ungual II (~13 mm), metatarsal III (~57.8 mm), phalanx III-1 (~18 mm), phalanx III-2 (~11.3 mm), phalanx III-3 (~11.3 mm), pedal ungual III (10.1 mm), metatarsal IV (57.4 mm), phalanx IV-1 (11.3 mm), phalanx IV-2 (9.9 mm), phalanx IV-3 (6.2 mm), metatarsal V (14.1 mm), feathers, scale impressions, pedal claw sheath
Diagnosis- (from Xu and Zhang, 2005) very slender pedal phalanx I-1 (length/mid-shaft-diameter ratio about 7.2).
Reference- Xu and Zhang, 2005. A new maniraptoran dinosaur from China with long feathers on the metatarsus. Naturwissenschaften. 92, 173-177.

Eumaniraptora incertae sedis

Buitreraptor Makovicky, Apesteguia and Agnolin, 2005
B. gonzalezorum Makovicky, Apesteguia and Agnolin, 2005
Cenomanian-Turonian, Late Cretaceous
Candeleros Formation of the Rio Neuquen Subgroup, Argentina
Holotype- (MPCA 245) (adult) incomplete skull (~190 mm), incomplete mandibles (~166 mm), seven cervical vertebrae (~200 mm), cervical ribs, thirteen dorsal vertebrae (205 mm), fifteen dorsal ribs, sacrum (57 mm), fifteen caudal vertebrae (~345 mm), nine chevrons, incomplete scapulae (~96 mm), coracoids (45 mm), furcula (~73 mm), humeri (135 mm), radii (95 mm), ulnae (110 mm), semilunate carpal, three partial metacarpals, partial ilim, ischium (54 mm), femora (~143, ~145 mm), partial tibiae (>149 mm), partial fibula (>127 mm), distal metatarsi, phalanx II-1 (22 mm), phalanx II-2 (18 mm), pedal phalanges
Paratype- (MPCA 238) sacrum, pelves, hindlimbs
Referred- two individuals (Anonymous, 2005)
Comments- This taxon was first placed in a basal dromaeosaurid clade with Rahonavis and Unenlagia, named Unenlagiinae (Makovicky et al., 2005). However, after correcting some errors in their matrix, it emerges as an avialan basal to Archaeopteryx, Rahonavis and pygostylians. Archaeopteryx has six of the unenlagiine and Rahonavis + Unenlagia characters suggested by them (all dorsals pleurocoelous; short dorsal transverse processes; lateral cuppedicus ridge extending posteriorly; supracetabular crest; mesopuby; elongate preacetabular process), and is polymorphic for three (dorsally concave postacetabular process; large proximodorsal ischial process; elongate obturator process). The only one it lacks is six sacral vertebrae. There are seven characters placing unenlagiines by dromaeosaurs in Makovicky et al.'s tree. The sinusoidal supratemporal fossa edge is only known in Buitreraptor among unenlagiines, and is also present in the basal Ukhaa Tolgod troodontid and Troodon, though absent in Mei and Saurornithoides. So it has a somewhat ambiguous distribution among deinonychosaurs, though Archaeopteryx does lack it. I don't feel comfortable coding any non-dromaeosaur paravian for paraquadrate foramen size, including Mei and Archaeopteryx (the only two coded for it by the TWG). In Mei, the dorsal quadratojugal process is missing, while Archaeopteryx never has the two bones visible posteriorly. Buitreraptor does have unconstricted tooth roots, but Microraptor doesn't. Distally placed cervical epipophyses are actually present in pygostylians, Archaeopteryx and most troodontids (Mei, Sinornithoides, Byronosaurus). Of these, Makovicky et al. only coded Mei for the character. So this doesn't support placing Buitreraptor with dromaeosaurids either. Stalked dorsal parapophyses are found in Buitreraptor and dromaeosaurids, but also in Confuciusornis and Mei (and further down, alvarezsaurids). They are thus possibly diagnostic for Paraves or Eumaniraptora instead, and lost in Archaeopteryx and derived troodontids. The posteriorly bifurcated chevrons that supposedly join Buitreraptor, Rahonavis and dromaeosaurids (Velociraptor, Graciliraptor, Microraptor) are also found in the troodontids Jinfengopteryx and Sinornithoides, as well as Shenzhouraptor. They are absent in Achillobator, Saurornitholestes, Mei, Sinovenator, derived troodontids and Archaeopteryx. So they could support a basal troodontid or basal ornithurine position as well. Finally, the ginglymoid metatarsal II of Rahonavis, Neuquenraptor and Buitreraptor is seen not only in dromaeosaurids, but also in scansoriopterygids, the basal troodontid IGM 100/44 and Confuciusornis (the latter two miscoded by Makovicky et al.). The totality of evidence suggests Buitreraptor may be a basal dromaeosaurid, unenlagiine or basal avialan.
References- Anonymous, 2005. Newly discovered birdlike dinosaur is oldest raptor ever found in South America.
Makovicky, Apesteguía and Agnolín, 2005. The earliest dromaeosaurid theropod from South America. Nature. 437, 1007-1011.

Mahakala Turner, Pol, Clarke, Ericson and Norell, 2007
M. omnogovae Turner, Pol, Clarke, Ericson and Norell, 2007
Campanian, Late Cretaceous
Djadokhta Formation, Mongolia
Holotype- (IGM 100/1033) (~700 mm; adult) frontals (25.2 mm), quadrate, posterior braincase, atlas, axis, anterior third cervical vertebra, sacrum, first caudal vertebra, second caudal vertebra, third caudal vertebra, fourth caudal vertebra, fifth caudal vertebra, sixth caudal vertebra, seventh caudal vertebra, eighth caudal vertebra, ninth caudal vertebra, tenth caudal vertebra, eleventh caudal vertebra, twelfth caudal vertebra, thirteenth caudal vertebra, three chevrons, scapula, incomplete humerus (~35-40 mm), radius, ulna (~40 mm), semilunate carpal, metacarpal I, metacarpal II (18 mm), metacarpal III, manual unguals, incomplete ilium (52.5 mm), femur (76.2 mm), tibia (110 mm), fibula, astragalus, calcaneum, metatarsal I, metatarsal II, phalanx II-2, pedal ungual II (17.8 mm), metatarsal III (82 mm), phalanx III-1 (19.1 mm), phalanx IV-1, proximal phalanx IV-2
Diagnosis- (after Turner et al., 2007) strongly compressed and anteroposteriorly broad ulna tapering posteriorly to a narrow edge; elongate lateral crest on the posterodistal part of the femur; proximal caudal vertebrae with subhorizontal, laterally directed prezygapophyses.
Comments- This may be a basal dromaeosaurid (as in Turner et al., 2007) or a basal paravian.
References- Turner, Pol, Clarke, Ericson and Norell, 2007. A basal dromaeosaurid and size evolution preceding avian flight. Science. 317, 1378-1381.
Erickson, Rauhut, Zhou, Turner, Inouye, Hu and Norell, 2009. Was dinosaurian physiology inherited by birds? Reconciling slow growth in Archaeopteryx. PLoS ONE. 4(10), e7390. doi:10.1371/journal.pone.0007390

Rahonavis Forster, Sampson, Chiappe and Krause, 1998
= Rahona Forster, Sampson, Chiappe and Krause, 1998 (preoccupied)
R. ostromi (Forster, Sampson, Chiappe and Krause, 1998) Forster, Sampson, Chiappe and Krause, 1998
= Rahona ostromi Forster, Sampson, Chiappe and Krause, 1998
Maastrichtian, Late Cretaceous
Maevarano Formation, Madagascar
Holotype- (UA 8656) ninth cervical vertebra, eighth to thirteenth dorsal vertebrae, synsacrum (41.9 mm), first to thirteenth caudal vertebrae, scapula (82.2 mm), radius (126.9 mm), ulna (132.3 mm), ilia (66.7, 67.7 mm), pubes (60.8 mm), ischia (27.3 mm), femora (88, 87.1 mm), tibiae (119.8, 120.2 mm), fibula, astragali, calcanea, metatarsal I (8.9 mm), phalanx I-1 (9.6 mm), pedal ungual I (10.6 mm), metatarsal II (44.7, 44.1 mm), phalanx II-1 (12 mm), phalanx II-2 (10.6 mm), pedal ungual II (19.7 mm), metatarsal III (48, 48.1 mm), phalanx III-1 (19.2 mm), phalanx III-2 (13 mm), phalanx III-3 (10.1 mm), metatarsal IV (45.3, 47.7 mm), phalanx IV-1 (14.4 mm), phalanx IV-2 (9.6 mm), phalanx IV-3 (6.7 mm)
Referred- ? two distal humeri (Forster and O'Conner, 2000)
Comments- This taxon has recently been found to clade with Unenlagia and Buitreraptor within Dromaeosauridae by the Theropod Working Group (Makovicky et al., 2005 and derivations), but they do not include all the characters which have been previously suggested to ally it with birds. When these are included, Rahonavis sometimes ends up as a bird more closely related to neornithines than archaeopterygids, but less than Shenzhouraptor, Jixiangornis, Dalianraptor, Yandangornis and pygostylians.
References- Forster, Sampson, Chiappe and Krause, 1998. The theropod ancestry of birds: New evidence from the Late Cretaceous of Madagascar. Science. 279, 1915-1919.
Forster, Sampson, Chiappe and Krause, 1998.
Schweitzer, Watt, Avci, Forster, Krause, Knapp, Rogers, Beech and Marshall, 1999. Keratin immunoreactivity in the Late Cretaceous bird Rahonavis ostromi. Journal of Vertebrate Paleontology. 19(4), 712-722.
Forster and O'Conner, 2000. The avifauna of the Upper Cretaceous Maevarano Formation, Madagascar. Journal of Vertebrate Paleontology. 20(3), 41A-42A.
Makovicky, Apesteguía and Agnolín, 2005. The earliest dromaeosaurid theropod from South America. Nature. 437, 1007-1011.

Cretaaviculus Bazhanov, 1969
C. sarysuensis Bazhanov, 1969
Santonian, Late Cretaceous
Bostobe Formation, Kazakhstan
Holotype- contour feather (17 mm)
Comments- This specimen is a small, asymmetric contour feather with a length of 17 mm and a width of 4.8-5.5 mm. The barbs are at a 20 degree angle to the shaft. The asymmetry suggests it is a paravian. Nessov (1992) considers it indeterminate, which is true so far as feather characteristics cannot be used to diagnose Mesozoic birds.
References- Bazhanov, 1969. [On the record of a bird remain living in the Cretaceous in the USSR]. Tezisy Dokladov XV Sessii Vsesoyuznogo Paleontologicheskogo Obshchestva. 5-6.
Shillin and Romanova, 1978. [Senonian floras of Kazakhstan]. Alma-Ata: Kairat Publishing. 176 pp.
Nessov, 1992. Mesozoic and Paleogene birds of the USSR and their paleoenvironments. in Campbell (ed). Papers in Avian Paleontology Honoring Pierce Brodkorb. 465–478.

Elopterygidae Lambrecht, 1933
Elopteryginae Lambrecht, 1933 sensu Le Loeuff, Buffetaut, Mechin and Mechin-Salessy, 1992
Elopteryx Andrews, 1913
E. nopcsai Andrews, 1913
Late Maastrichtian, Late Cretaceous
Sinpetru Beds, Romania
Holotype- (BMNH A1234) proximal femur (~150 mm)
Referred- (BMNH A1235) proximal femur (~150 mm) (Lambrecht, 1929)
Comments- Andrews (1913) originally described Elopteryx as a pelecaniform, referring the distal tibiotarsus BMNH A4329 to the same individual. Lambrecht (1929) referred two more distal tibiotarsi (BMNH A1528 and 1588) to it, as well as an additional proximal femur (BMNH A1234). Later, Lambrecht (1933) created the family Elopterygidae for the genus. Harrison and Walker (1975) removed the tibiotarsi, making them the type specimens of Bradycneme and Heptasteornis. Grigorescu and Kessler (1981) referred a distal femur (FGGUB R.351) to this taxon, which was reidentified as a ceratosaur by Csiki and Grigorescu (1998), then more certainly as a distal hadrosaurid metatarsal by Kessler et al. (2005). Jurcsak and Kessler (1986) reported a skull (FGGUB 1007) they referred to Elopteryx which supposedly supports an assignment to Pelecaniformes, but this has turned out to be from a sauropod (Csiki, pers. comm. 2007; illustrated in Weishampel et al., 1991). Le Loeuff et al. (1992) resynonymized Heptasteornis and Bradycneme with Elopteryx based on their bone texture. They also described a femur (MDE-D203), anterior dorsal vertebra (MDE-D01), posterior sacral vertebra (MDE coll.) and several fragmentary dorsal ribs from the Gres a Reptiles Formation of France which they believed were congeneric or at least related to Elopteryx. Le Loeuff et al. believed these remains were most closely related to dromaeosaurids, though perhaps deserving their own family or subfamily (Elopterygidae or Elopteryginae). Le Loeuff and Buffetaut (1998) referred the two vertebrae to their new dromaeosaurid genus Variraptor. The femur was only stated to share general characteristics with Elopteryx (reduced fourth trochanter, posterior trochanter, "shape and size") while differing in having a linear capital ligament fossa and absent fourth trochanter. It probably belongs to a distinct taxon of maniraptoran, and as the tibiotarsi and vertebrae are not even comparable to Elopteryx, the concept of a European clade of elopterygines or elopterygids is morphologically baseless. The Elopteryx holotype was identified as a derived maniraptoran by Csiki and Grigorescu (1998) and later as a troodontid or non-ornithuromorph pygostylian by Naish and Dyke (2004). Kessler et al. (2005) describe a mononykine distal femur (FGGUB R.1957) as Elopteryx based on bone texture, synonymizing Heptasteornis and Bradycneme with the genus again, and refer the taxon to Alvarezsauridae. I prefer to assign the femur to the mononykine Heptasteornis, while keeping Elopteryx separate as it differs from alvarezsaurids in some ways (posterior trochanter and capital ligament fossa present).
References- Andrews, 1913. On some bird remains from the Upper Cretaceous of Transylvania. Geological Magazine. 5, 193-196.
Lambrecht, 1929. Mesozoische und tertiare Vogelreste aus Siebenburgen. In Csiki (ed.). Xe Congres International de Zoologie. 1262-1275.
Lambrecht, 1933. Handbuch der Palaeornithologie. Berlin: Gebrüder Borntraeger. 1024 pp.
Harrison and Walker, 1975. The Bradycnemidae, a new family of owls from the Upper Cretaceous of Romania. Palaeontology. 18(3), 563-570.
Grigorescu and Kessler, 1981. A new specimen of Elopteryx nopcsai from the dinosaurian beds of Hateg Basin. Revue Roumaine de Geologie, Geophysique et Geographie, Geologie. 24, 171-175.
Jurcsak and Kessler, 1986. The evolution of the Roumanien bird fauna, Part I. The history of the studies. Crisia 16, 577-615, Oradea. [in Roumanian, with English abstract]
Kessler, 1987. New contributions to the knowledge about the Lower and Upper Cretaceous birds from Romania. Occasional Papers of the Tyrrell Museum of Palaeontology. 3, 133-135.
Weishampel, Grigorescu and Norman, 1991. The dinosaurs of Translyvania.National Geographic Research and Exploration. 7(2), 196-215.
Le Loeuff, Buffetaut, Mechin and Mechin-Salessy, 1992. The first record of dromaeosaurid dinosaur (Saurichia, Theropoda) in the Maastrichtian of Southern Europe: palaeobiogeographical implications. Bulletin de la Societe Geologique de France. 163(3), 337-343.
Le Loeuff and Buffetaut, 1998. A new dromaeosaurid theropod from the Upper Cretaceous of Southern France. Oryctos. 1, 105-112.
Csiki and Grigorescu, 1998. Small Theropods from the Late Cretaceous of the Hateg Basin (Western Romania) - an unexpected diversity at the top of the food chain. Oryctos. 1, 87-104.
Naish and Dyke, 2004. Heptasteornis was no ornithomimid, troodontid, dromaeosaurid or owl: the first alvarezsaurid (Dinosauria: Theropoda) from Europe. Neus Jahrbuch für Geologie und Paläontologie. 7, 385-401.
Kessler, Grigorescu and Csiki, 2005. Elopteryx revisited - a new bird-like specimen from the Maastrichtian of the Hateg Basin. Acta Palaeontologica Romaniae. 5, 249-258.

Timimus Rich and Vickers-Rich, 1994
T. hermani Rich and Vickers-Rich, 1994
Early Albian, Early Cretaceous
Eumeralla Formation of the Otway Group, Victoria, Australia
Holotype- (NMV P186303) femur (440 mm)
Paratype- (NMV P186323) femur (195 mm)
Referred- ? vertebrae (Rich and Vickers-Rich, 1994; Currie et al., 1996)
Early Aptian, Early Cretaceous
Wonthoggi Formation of the Strzelecki Group, Victoria, Australia
?(NMV P186058) pubis (Currie et al., 1996)
? caudal vertebra (Currie et al., 1996)
? ungual (Pigdon, online)
Comments- This taxon was only briefly described by Rich and Vickers-Rich (1994), and available photos of the femora are not very useful for determining morphology. It was referred to Ornithomimosauridae [sic] within Ornithomimosauria, though without explicit supporting evidence. The authors did list two characters to distinguish ornithomimosaur femora from carnosaurs' though- anteroposteriorly compressed head; anterior trochanter extends proximal to greater trochanter. At least the latter is definitely present in Timimus, and is only known in Gasosaurus, tyrannosaurids, Aniksosaurus, alvarezsaurids and maniraptorans. It is absent in ornithomimosaurs, contra Rich and Vickers-Rich, making it unlikely Timimus belongs to this clade. As for the compressed femoral head, this is not significantly different from Allosaurus or Tyrannosaurus in Sinornithomimus or Gallimimus, while it is slightly anteroposteriorly compressed in Archaeornithomimus and proximodistally compressed in Sinornithomimus. Rich and Vickers-Rich also list one character to distinguish "ornithomimosaurids" from elmisaurids (presumably within Ornithomimosauria, though elmisaurids are now known to be caenagnathid oviraptorosaurs)- proximally placed anterior trochanter base. Yet the distally placed base in the "elmisaurid" Chirostenotes is an autapomorphy not seen in other coelurosaurs. Alternatively, it may be a misinterpreted accessory trochanter. Thus there are no valid published reasons for referring Timimus to Ornithomimosauria or Ornithomimidae. The authors diagnose Timimus solely on the basis of lacking an extensor groove, presumably compared to Gallimimus which has an autapomorphic closed groove. Yet other ornithomimosaurs (Garudimimus, Sinornithomimus, Archaeornithomimus) lack extensor grooves, which is similar to most maniraptoriforms. Salisbury et al. (2007) state that Timimus is paravian and shares characters with unenlagiine deinonychosaurs. Unfortunately, no particular features were mentioned in this abstract. While Timimus' distal femur is roughly similar to Rahonavis' in anterior view, unenlagiine femora are more slender, have dorsally convex femoral heads and lower anterior trochanters. It is provisionally placed in Paraves here. Britt (1993) mentions NMV 186303 as a dromaeosaurid dorsal vertebra. This may be a typo for NMV 186302, an oviraptorosaur dorsal vertebra described by Currie et al. (1996).
Rich and Vickers-Rich also mention "a number of vertebrae" from Victoria they refer to ornithomimosaurs, but do not list in the hypodigm of Timimus. Currie et al. (1996) mention a pubis and vertebrae from the type locality and the Strzelecki Group. Finally, Pigdon (online) mentions a possible ornithomimosaur ungual from the Strzelecki Group found in 1996. He notes a Strzelecki vertebra is a caudal. Yet with Timimus probably not an ornithomimosaur, the identification of these elements comes into question too. Besides basal coelurosaurs, alvarezsaurids and maniraptorans, noasaurids might be expected to be confused for ornithomimosaurs, especially in the case of the pubis.
References- Britt, 1993. Pneumatic postcranial bones in dinosaurs and other archosaurs. PhD Thesis, University of Calgary (Canada), Alberta.
Rich and Vickers-Rich, 1994. Neoceratopsians and ornithomimosaurs: Dinosaurs of Gondwana origins? National Geographic Research. 10(1), 129-131.
Currie, Vickers-Rich and Rich, 1996. Possible oviraptorosaur (Theropoda, Dinosauria) specimens from the Early Cretaceous Otway Group of Dinosaur Cove, Australia. Alcheringa. 20(1-2), 73-79.
http://www.geocities.com/dannsdinosaurs/austfram-th.html
Salisbury, Agnolin, Ezcurra and Pias, 2007. A critical reassessment of the Creaceous non-avian dinosaur faunas of Australia and New Zealand. Journal of Vertebrate Paleontology. 27(3), 138A.

Wyleyia Harrison and Walker, 1973
W. valdensis Harrison and Walker, 1973
Late Berriasian-Valanginian, Early Cretaceous
Hastings Beds, England
Holotype- (BMNH A3658) humerus (42.4 mm)
Diagnosis- brachial fossa present on distal humerus.
Comments- Wyleyia may be an enantiornithine or dromaeosaurid based on- deltopectoral crest projected dorsally (also in Sapeornis, Archaeopteryx, Shenzhouraptor, Jixiangornis, Confuciusornis, Ambiortus, Apsaravis, Gansus and Ichthyornis); well-developed fossa on midline of proximal humerus making articular surface appear V-shaped in proximal view. It is not a euenantiornithine, as it lacks - proximal edge of humeral head concave in central portion; pneumotricipital fossa in proximal humerus. Furthermore, although the area is broken, the bicipital crest may not be hypertrophied, excluding Wyleyia from the Longipteryx+Enantiornis clade.
References- Harrison and Walker, 1973. Wyleyia: a new bird humerus from the Lower Cretaceous of England. Palaeontology. 16(4), 721-728.
Feduccia, 1980. The Age of Birds. Harvard University Press, Cambridge, Mass.
Norman, 1990. Problematic Theropoda: 'Coelurosauria'. In Weishampel, Dodson and Osmolska, eds. The Dinosauria. University of California Press, Berkeley. 280–305.
Harrison, 1991. Fossil birds. In Brooke and Birkhead, eds. The Cambridge Encyclopedia of Ornithology. Cambridge University Press, Cambridge. 69–76.
Kurochkin, 1995. Synopsis of Mesozoic birds and early evolution of Class Aves. Archaeopteryx. 13, 47–66.
Naish, 2002. The historical taxonomy of the Lower Cretaceous theropods (Dinosauria) Calamospondylus and Aristosuchus from the Isle of Wight. Proceedings of the Geologists' Association. n. 113, p. 153-163.

undescribed eumaniraptoran (Lambe, 1902)
Late Campanian, Late Cretaceous
Dinosaur Park Formation, Alberta, Canada
Material- (CMN coll.) proximal caudal vertebra
Comments- This was identified by Lambe (1902) as a posterior dorsal vertebra tentatively referred to Struthiomimus (his Ornithomimus altus) (plate XV figure 6-8), but is actually a caudal, and may be Troodon or Saurornitholestes based on its low square articular face.
Reference- Lambe, 1902. New genera and species from the Belly River Series (mid-Cretaceous). Geological Survey of Canada Contributions to Canadian Palaeontology. 3(2), 25-81.

unnamed eumaniraptoran (Jensen, 1981)
Late Kimmeridgian, Late Jurassic
Brushy Basin Member of the Morrison Formation, Colorado, US
Material- (BYUVP 2023) femur
Comments- This was first referred to Archaeopteryx by Jensen (1981), then to Theropoda indet. by Molnar (1985) and Maniraptora indet. by Jensen and Padian (1989). The large posterior trochanter indicates an assignment to either Avimimidae or Paraves, while the absence of a trochanteric crest excludes referral to Ornithurae (sensu Gauthier) or Troodontidae. The deeply separated anterior and greater trochanters are more similar to Avimimus, Unenlagia, Microraptor and Archaeopteryx, but unlike derived dromaeosaurids. The absent fourth trochanter eliminates Avimimus from consideration. It is here assigned to Eumaniraptora indet. pending further study. It may belong to "Paleopteryx", as the latter appears to be a microraptorian.
References- Jensen, 1981. [A new oldest bird?] Anima (Tokyo). 1981, 33-39. [in Japanese]
Jensen, 1981. Another look at Archaeopteryx as the worlds oldest bird. Encyclia, The Journal of the Utah Academy of Sciences, Arts, and Letters. 58, 109-128.
Molnar, 1985. Alternatives to Archaeopteryx; a survey of proposed early or ancestral birds. in Hecht, Ostrom, Viohl and Wellnhofer (eds). The Beginnings of Birds. Eichstatt, Germany: Freunde des Jura-Museums Eichstatt. 209-217.
Jensen and Padian, 1989. Small Pterosaurs and Dinosaurs from the Uncomphagre fauna (Brushy Basin Member, Morrison Formation: ?Tithonian), Late Jurassic, Western Colorado. Journal of Paleontology. 63(3), 364-373.
Padian, 1998. Pterosaurians and ?avians from the Morrison Formation (Upper Jurassic, Western U.S.). Modern Geology. 23, 57-68.

undescribed Eumaniraptora (Nessov, 1977)
Early Cenomanian, Late Cretaceous
Khodzhakul Formation, Uzbekistan
Material- teeth
Comments- Identified as Deinonychosauria by Nessov (1995).
References- Nessov, 1977. [Turtles and some other reptiles of the Cretaceous of Karakalpakia]. Voprosy gyerpyetology. Chyetvyertaya Vsyesoyuznaya Gyerpyetologichyeskaya konfyeryentsiya, Lyeningrad. Avtoryefyerat doklada. Lyeningrad, Nauka. 155-156.
Nessov, 1995. Dinosaurs of nothern Eurasia: new data about assemblages, ecology, and paleobiogeography. Institute for Scientific Research on the Earth's Crust, St. Petersburg State University, St. Petersburg. 1-156.

unnamed eumaniraptoran (Buffetaut, Marandat and Sige, 1986)
Late Cretaceous
Serviers, Gard, France
Material- (Universite des Sciences et Techniques de Languedoc SER 03) partial tooth (~2.2 mm)
Comments- This tooth is relatively elongate and barely revurved. It has 14 distal serrations per mm, while the mesial serrations are indistinct. It was assigned to Dromaeosauridae by Buffetaut et al. (1986), but is most similar to supposed bird teeth from the Dinosaur Park Formation (Sankey et al., 2002) in its small size, tiny serrations, lack of much recurvature, and constricted base.
References- Buffetaut, Marandat and Sige, 1986. Decourvert de dents de Deinonychosaures (Saurischia, Theropoda) dans le Creace superieur du Sud de la France. Les Comptes rendus de l'Académie des sciences. 303, Serie II(15), 1393-1396.
Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.

unnamed eumaniraptoran (Buffetaut, Marandat and Sige, 1986)
Late Campanian-Early Maastrichtian, Late Cretaceous
Champ-Garimond, Gard, France
Material- (Universite des Sciences et Techniques de Languedoc CHG 48) tooth (1.9 mm)
Comments- This tooth is short and slightly recurved, with a constricted base. There are 15 distal serrations per millimeter, while mesial serrations are only present as fine outlines. Like SER 03, it was assigned to Dromaeosauridae by Buffetaut et al. (1986), but is most similar to supposed bird teeth from the Dinosaur Park Formation (Sankey et al., 2002) in its small size, tiny serrations which are absent mesially, lack of much recurvature, and constricted base.
References- Buffetaut, Marandat and Sige, 1986. Decourvert de dents de Deinonychosaures (Saurischia, Theropoda) dans le Creace superieur du Sud de la France. Les Comptes rendus de l'Académie des sciences. 303, Serie II(15), 1393-1396.
Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.

unnamed probable eumaniraptoran (Weigert 1995)
Kimmeridgian, Late Jurassic
Guimarota Formation, Portugal
Material- (IPFUB GUI ARCH. 1) tooth
(IPFUB GUI ARCH. 3) tooth
(IPFUB GUI ARCH. 4) tooth
(IPFUB GUI ARCH. 5) tooth
(IPFUB GUI ARCH. 7) tooth
(IPFUB GUI ARCH. coll.) 98 teeth (1-2.6 mm)
Comments- These teeth are constricted basally, with mesial and distal carinae. Both lingual and labial surfaces are generally smooth, and the lingual surface is concave apically. The labial surface sometimes has faint grooves, which were believed to be from wear. Eighty-six teeth have both mesial and distal serrations, while the other seventeen sometimes lack mesial serrations and have carinae shifted lingually, so are probably premaxillary teeth. The teeth average 1.65 mm in crown height and .60 mm in FABL. Serrations are low and rounded or slightly pointed, with a miniscule size of 24/mm.
The specimens differ from Archaeopteryx and other avialans in having serrations. Weigert (1995) states these may be present but hidden in the former genus, since most Archaeopteryx teeth are only visible in labial view, where the serrations cannot be seen in the Guimarota specimens. Yet the London and Munich specimens of Archaeopteryx both expose serrationless teeth in lingual view, showing Weigert is incorrect. He explained the absence of serrations in the Munich specimen by claiming it was a distinct species (A. bavarica) which may have differed from A. lithographica in this respect, but this is special pleading, and the distinctness of A. bavarica is very poorly supported (see discussion in Archaeopteryx entry). The diagonally oriented carina on the apical half of the tooth is described as an archaeopterygiform apomorphy, but this is true of any teeth which share the same stout, highly recurved outline (e.g. Sinornithoides). The other cited archaeopterygiform apomorphy is the lingually projected mesial carina, but this is found in other taxa such as Sinornithosaurus' anterior teeth. The teeth do seem to be maniraptoriform, based on the constricted crown base, and are not referrable to several groups due to their serrations (Ornithomimoidea, Oviraptorosauria, Avialae), but also lack the enlarged serrations found in most therizinosaurs and derived troodontids. They may belong to a basal troodontid or dromaeosaurid, but are not archaeopterygid.
Reference- Weigert, 1995. Isolierte Zahne von cf. Archaeopteryx sp. aus dem Oberen Jura der Kohlengrube Guimarota (Portugal). N. Jb., Geol. Palaont. Mh. 9, 562-576.

unnamed eumaniraptoran (Rodriguez de la Rosa and Cevallos-Ferriz, 1998)
Late Campanian, Late Cretaceous
Cerro del Pueblo Formation, Mexico
Material- (IGM-7711) pedal phalanx II-I (18.8 mm)
(IGM-7712) pedal phalanx II-2 (21.7 mm)
Comments- These may belong to the same individual, which was tentatively referred to Troodontidae by Rodriguez de la Rosa and Cevallos-Ferriz (1998) based on the centrally placed collateral ligament pit, which is also found in Saurornithoides and Troodon. However, the slightly longer II-2 compared to II-1 is more similar to dromaeosaurids. It is from a different taxon than IGM-7710 as it is not nearly as elongate, and different from IGM-7715 as it has a centrally placed collateral ligament pit.
Reference- Rodriguez de la Rosa and Cevallos-Ferriz, 1998. Vertebrates of the El Pelillal locality (Campanian, Cerro del Pueblo Formation), Southeastern Coahuila, Mexico. Journal of Vertebrate Paleontology. 18, 751-764.

unnamed eumaniraptoran (Rodriguez de la Rosa and Cevallos-Ferriz, 1998)
Late Campanian, Late Cretaceous
Cerro del Pueblo Formation, Mexico
Material- (IGM-7715) distal pedal phalanx II-2
Comments- This was tentatively referred to Dromaeosauridae by Rodriguez de la Rosa and Cevallos-Ferriz (1998) based on the dorsally placed collateral ligament pit. However, this character is also present in basal troodontids (e.g. IGM 100/44, Sinornithoides, Borogovia), Neuquenraptor and Rahonavis. It is a different taxon than IGM-7710 and IGM-7712, both of which have centrally placed collateral ligement pits.
Reference- Rodriguez de la Rosa and Cevallos-Ferriz, 1998. Vertebrates of the El Pelillal locality (Campanian, Cerro del Pueblo Formation), Southeastern Coahuila, Mexico. Journal of Vertebrate Paleontology. 18, 751-764.

undescribed probable eumaniraptoran (Norton, DML 2000)
Late Campanian, Late Cretaceous
Djadochta Formation, Mongolia
Material- (IGM 97/155)
Comments- Norton (DML, 2000) noted this specimen was on display at the AMNH Fighting Dinosaurs exhibit. Discovered in 1997 at Ukhaa Tolgod, it is said to be unpublished but exhibit "raptor-like" traits.
Reference- http://dml.cmnh.org/2000Jun/msg00082.html

undescribed eumaniraptoran (Bertini, Santucci and Arruda-Campos, 2001)
Late Maastrichtian, Late Cretaceous
Echapora Member of the Marilia Formation of the Bauru Group, Brazil
Material- (MPMA-73) tooth
Comments- This was listed as a deinonychosaur tooth, but has not yet been illustrated or described.
Reference- Bertini, Santucci and Arruda-Campos, 2001. Titanossauros (Sauropoda: Saurischia) no Cretaceo Superior continental (Formaceo Marilia, Membro Echapora) de Monte Alto, Estado de São Paulo, e correlacao com formas associadas no Triangulo Mineiro. Geociencias, Sao Paulo. 20(1/2), 93-103.

undescribed possible eumaniraptoran (Amiot, Buffetaut, Tong, Boudad and Kabiri, 2002)
Cenomanian, Late Cretaceous
Kem Kem Beds, Morocco
Material- (M-ZA-017) tooth (14 mm) (Amiot, Buffetaut, Tong, Boudad and Kabiri, 2004)
Comments- This tooth is straight and short, with a BW/FABL of 0.6. The lingual side is concave, and the labial side convex. Both carinae have serrations which are apically inclined and lie on the midline. Mesial serrations (2/mm) and dista1 serrations (2.1/mm) are both large, with shallow interdenticle pits.
Amiot et al. (2002) first referred this specimen to Troodontidae based on the lens-shaped cross section, low DSDI, and large serrations which are apically inclined. They later (2004) referred it to Dromaeosauridae, as Currie said the base was too narrow and the serrations resembled dromaeosaurids.
References- Amiot, Buffetaut, Tong, Boudad and Kabiri, 2002. Laurasian theropod dinosaur teeth from the Late Cretaceous of Morocco. Conference abstract, Third Georges Cuvier Symposium, Montbeliard, France.
Amiot, Buffetaut, Tong, Boudad and Kabiri, 2004. Isolated theropod teeth from the Cenomanian of Morocco and their palaeobiogeographical significance. Revue de Paleobiologie, Geneve. 9, 143-149.

unnamed Eumaniraptora (Franco-Rosas, 2002)
Turonian-Late Maastrichtian, Late Cretaceous
Adamantina and Marilia Formations of the Bauru Group, Brazil
Material- teeth
Description- These teeth have long serrations with varied slopes and distal shapes, and slightly pronounced interdenticle slits. They are said to be similar to troodontids and velociraptorines.
Reference- Franco-Rosas, 2002. Methodological parameters for the identification and taxonomic classification of isolated theropodomorph teeth. Anais da Academia Brasileira de Ciencias. 74(2), 367.

unnamed probable Eumaniraptora (Sankey, Brinkman, Guenther and Currie, 2002)
Late Campanian, Late Cretaceous
Dinosaur Park Formation of the Judith River Group, Alberta, Canada
Material- (RTMP 84.92.205) tooth (2.7 mm)
(RTMP 86.21.68) tooth (3.7 mm)
(RTMP 86.45.27) tooth (3.7 mm)
(RTMP 86.52.54) tooth (4.7 mm)
(RTMP 86.172.53) tooth (2.9 mm)
(RTMP 87.4.19) tooth (5.5 mm)
(RTMP 87.4.46) tooth (3.6 mm)
(RTMP 87.20.8) tooth (4.3 mm)
(RTMP 87.30.10) tooth (~3.7 mm)
(RTMP 87.158.76) tooth (3.3 mm)
(RTMP 87.158.77) tooth (3.1 mm)
(RTMP 88.11.65) tooth (2.9 mm)
(RTMP 89.103.25) tooth (5.4 mm)
(RTMP 95.145.34a) tooth (2.1 mm)
(RTMP 95.145.34b) tooth (4 mm)
(RTMP 95.145.34c) tooth (3.5 mm)
(RTMP 95.147.30) tooth (2.4 mm)
(RTMP 95.151.21) tooth (2.3 mm)
(RTMP 95.174.52) tooth (2.3 mm)
(RTMP 95.177.79) tooth (3 mm)
(RTMP 95.180.49) tooth (3.2 mm)
(RTMP 95.181.10a) tooth (3.1 mm)
(RTMP 95.181.10b) tooth (3.3 mm)
(RTMP 95.181.10c) tooth (3.3 mm)
(RTMP 95.181.10d) tooth (3.3 mm)
(RTMP 95.181.60e) tooth (2.4 mm)
(RTMP 95.181.60f) tooth (2.5 mm)
(RTMP 96.62.51) tooth (3.2 mm)
(RTMP 96.62.62) tooth (3.5 mm)
(RTMP 96.62.62a) tooth (3.8 mm)
(RTMP 96.62.62b) tooth (2.7 mm)
Comments- These teeth are distinguished from other Dinosaur Park theropods by their small size, constricted bases, slight recurvature, and general absence of serrations. Distal serrations are present in about a fourth of the sample and are tiny (>8/mm), while minute mesial serrations are only present in one tooth (RTMP 89.103.25). About half have distinct carinae. Some resemble Mononykus except for their concave distal edge. Others most closely resemble hesperornithines, as noted by Sankey et al. (2002). Those authors referred the teeth to Aves indet., but also noted Microraptor has similar teeth. However, neither alvarezsaurids nor ornithurines (sensu Gauthier) have been reported to have serrations. Microraptor has highly heterodont dentition where the anterior serrationless teeth are more recurved and lack a basal constriction, while the posterior teeth are similar except in having slightly larger serrations (8/mm).
Reference- Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.

undescribed eumaniraptoran (Poblete and Calvo, 2003)
Late Turonian-Early Coniacian, Late Cretaceous
Portezuelo Formation of Rio Neuquen Group, Argentina
Material- teeth
Description- These are labiolingually compressed teeth with strongly posteriorly inclined crowns which are sometimes proportionally short. They lack mesial serrations but have distal ones. A labial carina is present, continuing apically to the tip of the distal side. It sometimes has small serrations.
Comments- It's possible they are referrable to Unenlagia? paynemili from the same quarry.
Reference- Poblete and Calvo, 2003. Upper Turonian Dromaeosaurid teeth from Futalognko quarry, Barreales Lake, Neuquén, Patagonia, Argentina. XIX Jornadas Argentinas de Paleontología de Vertebrados. Buenos Aires.

undescribed Eumaniraptora (Ikejiri, Watkins and Gray, 2006)
Late Kimmedidgian, Late Jurassic
Brushy Basin Member of the Morrison Formation, Wyoming, US
Material- (WDC BS-641) tooth
(WDC BS-885) tooth
(WDC BS-889) tooth
Reference- Ikejiri, Watkins and Gray, 2006. Stratigraphy, sedimentology, and taphonomy of a sauropod quarry from the Upper Jurassic Morrison Formation of Themopolis, central Wyoming. in Foster and Lucas (eds.). New Mexico Museum of Natural History Bulletin. 36, 36-46.

Troodontidae Gilmore, 1924
Definition- (Troodon formosus <- Ornithomimus velox, Mononykus olecranus, Therizinosaurus cheloniformes, Oviraptor philoceratops, Velociraptor mongoliensis, Passer domesticus) (modified from Senter et al., 2004)
Other definitions- (Troodon formosus, Saurornithoides mongoliensis, Borogovia gracilicrus, Sinornithoides youngi <- Ornithomimus velox, Oviraptor philoceratops) (Varricchio, 1997)
(Troodon formosus <- Velociraptor mongoliensis) (Makovicky and Norell, 2004; modified from Sereno, 1998)
(Troodon formosus <- Deinonychus antirrhopus, Passer domesticus) (Hu, Hou, Zhang and Xu, 2009)
(Troodon formosus <- Ornithomimus edmontonicus, Velociraptor mongoliensis, Passer domesticus) (Sereno, in press)
= Saurornithoididae Barsbold, 1974
= Archaeornithoididae Elzanowski and Wellnhofer, 1992
= Troodontidae sensu Sereno, 1998
Definition- (Troodon formosus <- Velociraptor mongoliensis) (modified)
= Troodontidae sensu Hu, Hou, Zhang and Xu, 2009
Definition- (Troodon formosus <- Deinonychus antirrhopus, Passer domesticus)
= Troodontidae sensu Sereno, in press
Definition- (Troodon formosus <- Ornithomimus edmontonicus, Velociraptor mongoliensis, Passer domesticus)
Comments- Sereno's newest (in press) definition differs from his earlier (1998) one which only had Velociraptor as an external specifier, and Senter et al.'s (2004), which had Mononykus, Therizinosaurus and Oviraptor as additional external specifiers. Keeping Oviraptor seems useful, in the case Osmolska and Barsbold (1990), Russell and Dong (1993) or Norell et al. (2001) are correct. I'm not aware of any topology placing Shuvuuia or Therizinosaurus closer to Troodon than the other taxa, but they both seem relatively plausible as troodontid sister taxa. Another specifier that might be useful considering recent discoveries is Archaeopteryx.
No longer troodontids- Currie et al. (1990) said that troodontid teeth reported from the Cedar Mountain Formation by Nelson and Crooks (1987) were more likely velociraptorines because of the serrations are small (12/mm) and elongate.
Although Metcalf and Walker (1994) identified a tooth from the Bathonian Chipping Norton Formation of England as a possible troodontid, it is more likely a dromaeosaurid.
Nessov (1995) cited a troodontid astragalocalcneum from the Bostobe Formation of Kazakhstan, but Averianov and Sues (2007) noted many other maniraptorans have fused astragalocalcanea as well. Kordokova et al. (1996) cited troodontids from the Zhirkindek and Bostobe Formations of Kazakhstan, but these were not mentioned in their later (2001) paper. Averianov (2007) could similarly not confirm the presence of troodontids from either formation.
Nessov (1995) identified CCMGE 484/12457 as a troodontid frontal, which he named Saurornithoides isfarensis. Though they could not locate it, Averianov and Sues (2007) reidentified the specimen as a hadrosaurid prefrontal.
References- Nelson and Crooks, 1987. Stratigraphy and paleontology of the Cedar Mountain Formation (Lower Cretaceous), eastern Emery County, Utah. In Averett (ed.), Paleontology and Geology of the Dinosaur Triangle: Guidebook for 1987 Field Trip. Museum of Western Colorado, Grand Junction. 55-63.
Currie, Rigby and Sloan, 1990. Theropod teeth from the Judith River Formation of southern Alberta, Canada. in Carpenter and Currie (eds.). Dinosaur Systematics: Perspectives and Approaches. Cambridge University Press, New York. pp. 107-125.
Metcalf and Walker, 1994. A new Bathonian microvertebrate locality in the English Midlands. in Fraser and Sues (eds.). In the Shadow of the Dinosaurs- Mesozoic Small Tetrapods, Cambridge (Cambridge University Press). 322-332.
Nessov, 1995. Dinosaurs of nothern Eurasia: new data about assemblages, ecology, and paleobiogeography. Institute for Scientific Research on the Earth's Crust, St. Petersburg State University, St. Petersburg 1-156.
Kordikova, Gunnell, Polly and Kovrizhinykh, 1996. Late Cretaceous and Paleocene Vertebrate Paleontology and stratigraphy in the Northeastern Aral Sea Region, Kazakstan. Journal of Vertebrate Paleontology. 16(3), 46A.
Kordikova, Polly, Alifanov, Rocek, Gunnell and Averianov, 2001. Small vertebrates from the Late Cretaceous and Early Tertiary of the Northeastern Aral Sea region, Kazakhstan. Journal of Pakeontology. 79(2), 390-400.
Zhao, 2003. The nesting behaviour of troodontid dinosaurs. Vertebrata Palasiatica. 41(2), 157-168.
Makovicky and Norell, 2004. Troodontidae. in Weishampel, Dodson and Osmolska (eds). The Dinosauria, Second Edition. California University Press. 184-195.
Averianov, 2007. Theropod dinosaurs from Late Cretaceous deposits in the northeastern Aral Sea region, Kazakhstan. Cretaceous Research.
Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.

"Paronychodontidae"
Diagnosis- at least one longitudinal ridge found on lingual side of teeth.
Comments- This family has yet to be officially named, but appears in quotes in references like Ruiz-Omenaca et al. (1998).
Reference- Ruiz-Omeñaca, Canudo, Cuenca-Bescós and Amo, 1998. Theropod teeth from the Lower Cretaceous of Galve (Teruel, Spain). Third European Workshop on Vertebrate Paleontology, Maastricht. 62-63.

unnamed paronychodontid (Zinke and Rauhut, 1994)
Kimmeridgian, Late Jurassic
Guimarota Formation, Portugal
Material- (IPFUB GUI D 1) dentary fragment, three teeth (Zinke and Rauhut, 1994)
(IPFUB GUI D 2) maxillary tooth (1.65 mm) (Zinke and Rauhut, 1994)
(IPFUB GUI D 3) tooth (Zinke and Rauhut, 1994)
(IPFUB GUI D 4-27) twenty-seven teeth (~1.67 mm) (Zinke, 1998)
Comments- IPFUB GUI D 1-3 teeth are recurved with one to two labial ridges and one to four lingual ridges. They have distal serrations which vary in size (6.5/mm in a tooth from GUI D 1; 14/mm in GUI D 2; 31/mm in GUI D 3), though they increase in size basally. GUI D 2 may have a slight basal constriction, and GUI D 3 is not flattened lingually. The mesial carina is unserrated (GUI D 2, GUI D 3), though GUI D 1 has small pits apically that may be worn serrations. Zinke notes all specimens have serrated distal carinae (6-13/mm) and some have serrated mesial carinae (~18/mm). They were identified by Zinke and Rauhut as cf. Paronychodon sp..
References- Zinke and Rauhut, 1994. Small theropods (Dinosauria, Saurischia) from the Upper Jurassic and Lower Cretaceous of the Iberian Peninsula. Berliner geowiss. Abh.. E 13, 163-177.
Zinke, 1998. Small theropod teeth from the Upper Jurassic coal mine of Guimarota (Portugal). Palaontologische Zeischrift. 72(1/2), 179-189.

unnamed paronychodontid (Zinke and Rauhut, 1994)
Early Barremian, Early Cretaceous
Camarillas Formation, Spain
Material- (JHM POCA-H7) anterior tooth (3.3 mm)
(JHM POCA-H8) lateral tooth (2.08 mm)
Comments- These teeth have 2-3 labial ridges and 3-4 lingual ridges. They lack mesial serrations, and have weak distal serrations (14-16/mm). Distal serrations are rounded and directed slightly apically.
References- Zinke and Rauhut, 1994. Small theropods (Dinosauria, Saurischia) from the Upper Jurassic and Lower Cretaceous of the Iberian Peninsula. Berliner geowiss. Abh.. E 13, 163-177.
Ruiz-Omenaca, 2006. Restos directos de dinosaurios (Saurischia, Ornithischia) en el Barremiense (Cretacico Inferior) de la Cordillera Iberica en Aragon (Teruel, Espana). Unpublished PhD Thesis. Universidad de Zaragoza. 584 pp.

unnamed paronychodontid (Pol, Buscalioani, Carballeira, Frances, Martinez, Marandat, Moratalla, Sanz, Sige and Villatte, 1992)
Maastrichtian, Late Cretaceous
Calizas de Lychnus Formation, Spain
Material- four teeth
Comments- These teeth were reported as cf. Paronychodon by Pol et al. (1992), then referred to cf. Euronychodon sp. by Canudo and Ruiz-Omenaca (2003), but they differ from both lacustris and portucalensis in being serrated distally.
References- Pol, Buscalioani, Carballeira, Frances, Martinez, Marandat, Moratalla, Sanz, Sige and Villatte, 1992. Reptiles and mammals from the Late Cretaceous new locality Quintanilla del Coco (Burgos Province, Spain). Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 184(3), 279-314.
Canudo and Ruiz-Omenaca, 2003. Los restos directos de dinosaurios teropódos (excluyendo Aves) en España [Direct remains of theropod dinosaurs (excluding Aves) in Spain]. Ciencias de la Tierra. 26, 347-373.

unnamed paronychodontid (Lopez-Martinez, Canudo, Ardevol, Pereda-Suberbiola, Orue-Etxebarria, Cuenca-Bescos, Ruiz-Omenaca, Muerlaga and Feist, 2001)
Late Maastrichtian, Late Cretaceous
Arenisca (=Upper Tremp) Formation, Spain
Material- (MPZ 98-76) tooth (2.74 mm)
(MPZ 98-77) tooth (2.79 mm)
(MPZ 98-78) tooth (2.23 mm)
Comments- These are strongly recurved and have three labial ridges. They were described as unserrated, however, MPZ 98-76 is listed as having 15.97 distal serrations per mm. They were listed as cf. Euronychodon sp. by Lopez-Martinez et al. (2001).
References- Canudo, Lopez Martinez and Ruiz Omenaca, 2001. Los dinosaurios del Maastrichtiense Superior (Cretacico Superior) del pirineo de Huesca (Espana). Actas de Las I Jornadas Internacionales sobre Paleontologia de Dinosaurios y su entorno. 319-328.
Lopez-Martinez, Canudo, Ardevol, Pereda-Suberbiola, Orue-Etxebarria, Cuenca-Bescos, Ruiz-Omenaca, Muerlaga and Feist, 2001. New dinosaur sites correlated with Upper Maastrichtian pelagic deposits in the Spanish Pyrenees: implications for the dinosaur extinction pattern in Europe. Cretaceous Research. 22, 41-61.

unnamed paronychodontid (Ruiz-Omeñaca, Canudo, Cuenca-Bescós and Amo, 1998)
Late Hauterivian-Early Barremian, Early Cretaceous
Castellar Formation, Spain
Material- (MPZ 98-11) tooth (5.32 mm)
Comments- Though this tooth has two ridges on both lingual and labial sides and no mesial serrations, it also has distal serrations (6/mm), so is here excluded from Paronychodon.
References- Ruiz-Omeñaca, Canudo, Cuenca-Bescós and Amo, 1998. Theropod teeth from the Lower Cretaceous of Galve (Teruel, Spain). Third European Workshop on Vertebrate Paleontology, Maastricht. 62-63.
Ruiz-Omenaca, 2006. Restos directos de dinosaurios (Saurischia, Ornithischia) en el Barremiense (Cretacico Inferior) de la Cordillera Iberica en Aragon (Teruel, Espana). Unpublished PhD Thesis. Universidad de Zaragoza. 584 pp.

Paronychodon Cope, 1876
= Euronychodon Antunes and Sigogneau-Russell, 1991
Diagnosis- serrations absent from teeth.
Comments- This genus is here restricted to paronychodontid teeth without serrations mesially or distally, following Currie et al. (1990). Estes (1964) included serrated specimens with ridges and flattened lingual sides in the genus as well, though these are here referred to Zapsalis abradens (= ?Dromaeosaurus morphotype A of Sankey et al., 2002) and the unnamed troodontid of Sankey et al. (2002). Many unstudied specimens catalogued or listed as Paronychodon probably belong to these two taxa. For instance, one photographed tooth of AMNH 27122 has distal serrations in addition to ridges, so is probably a Zapsalis specimen. Teeth matching the Paronychodon morphotype are known from the Barremian-Maastrichtian of North America and Eurasia, indicating it was probably a clade comparable to theropod families in scope, but which didn't show much dental variation. Once cranial and/or postcranial remains are identified, additional genera of paronychodontids will probably need to be named.
Relationships- Paronychodon was first compared to plesiosaurs by Cope (1876), who soon (1876) realized it was theropod based on comparison to Zapsalis. Most authors retain the genus as Theropoda incertae sedis, though some have tried to clarify its relationships further. Estes (1964) referred it to Coeluridae, while Russell (1984) referred it to Dromaeosauridae, and Osmolska and Barsbold (1990) to Troodontidae. These assignments were all done without justification.
More recently, Zinke and Rauhut (1994) suggested a sister group relationship to troodontids based on the large apically angled distal serrations of the Guimarota paronychodont teeth and the basal constriction in some teeth. These characters are now known in basal dromaeosaurids too (e.g. Microraptor). Rauhut and Zinke (1995) suggested assigning Una Formation Paronychodon teeth to Pelecanimimus, but Rauhut later (2002) considered this unlikely after communication with Perez-Moreno.
Rauhut suggested instead that at least the Una Paronychodon could be archaeopterygids, based on the constricted base, lingually bent carinae (forming mesial and distal grooves along the carinae lingually), and labiodistally twisted tips. Yet the last two characters have yet to be reported from Late Cretaceous Paronychodon, which differs from the Una specimens in several details in any case.
Another hypothesis was given in an abstract by Sankey (2002), who purported to show that Paronychodon is a morphotype of Richardoestesia? isosceles, based on morphology and relative abundance. The details of this study have yet to be published, though it does make sense stratigraphically, as both taxa first appear in Late Jurassic Europe and spread to North America in the Albian, with Late Cretaceous examples known from the Western North America, Central Asia and Europe. It's also logical anatomically, as Richardoestesia? isosceles would be expected to have some unserrated and possibly constricted teeth if it were microraptorian. It should be noted Paronychodon has priority over Richardoestesia, and lacustris and caperatus both have priority over isosceles. Also, Euronychodon has priority over Asiamericana, and portuculensis has priority over both asiatica and asiaticus. So if this synonymy is proven, none of the names associated with straight-toothed Richardoestesia will survive synonymization. Longrich (2008) proposed such a synonymy based on the weak longitudinal ridges on some Richardoestesia teeth, but Larson (2008) noted other contemporaneous theropods sometimes have weak ridges too (tyrannosaurids, 'velociraptorines') and that varied morphologies probably reflect positional variation in Paronychodon teeth. Thus it is unlikely they existed in the same jaws as Richardoestesia teeth.
Sues and Averianov (in prep.) will propose that Paronychodon are juvenile deinonychosaurs, probably in part based on Zapsalis-like specimens which mix paronychodontid longitudinal ridges with dromaeosaurine-like serrations. It is true that Paronychodon teeth are smaller than Dromaeosaurus teeth in the Dinosaur Park Formation, for instance, and that embryonic Troodon has serrationless teeth. Yet apparently intermediate Zapsalis teeth are not intermediate in size, as might be expected if they were subadults. This has not been published besides a mention by Averianov (2007) though, so is difficult to evaluate.
Hwang (2005, 2007) found that Paronychodon teeth are identical in enamel microstructure to serrationless troodontids like Byronosaurus and IGM 100/1323, while Richardoestesia more closely matched dromaeosaurids. Thus they are here placed as basal troodontids
Pachycephalosaur fangs?- An odd possibility was suggested by Olshevsky (DML, 1997), that some Paronychodon specimens, including the holotype, may be anterior dentary fangs of "homalocephalid" pachycephalosaurs (cf. Goyocephale) . However, the dentary fangs of Goyocephale are serrated distally, polygonal in section, have a bulbous root, and seem to only possess one lingual ridge. Premaxillary teeth of Goyocephale are somewhat similar to type B teeth of Paronychodon, but lack ridges, are much less labiolingually compressed, and have distal serrations apically. Stegoceras teeth are even less similar, being serrated both mesially and distally with no ridges. The supposed Middle Jurassic pachycephalosaur Ferganocephale has vertical enamel ridges on the base of one side and lacks serrations, but is otherwise highly distinct, being unrecurved, short and uncompressed labiolingually, with a prominent cingulum. The ridges radiate from the base instead of the apex and the entire tooth shape is distinctively ornithischian. Besides the anatomical differences, stratigraphically Paronychodon and "homalocephalids" are also mismatched, with the latter only known from the Campanian-Maastrichtian of Mongolia and perhaps China. The utter lack of "homalocephalids" in well sampled strata like the Dinosaur Park Formation is particularily telling. Also notable is that each "homalocephalid" only had eight fang-like teeth, but had around sixty-six leaf-shaped teeth. So we would expect more pachycephalosaur teeth by a factor of 8:1 or so (even more in Maastrichtian formations where pachycephalosaurines dominate, with no premaxillary teeth and greater numbers of cheek teeth), but Baszio (1997) showed this is not the case. For instance, he recorded 12 Paronychodon teeth from the Dinosaur Park Formation, and only 16 pachycephalosaur teeth. Similarly, Baszio recorded 84 Paronychodon teeth from the Milk River Formation, but only 16 pachycephalosaur teeth. Finally, Zinke and Rauhut (1994) described paronychodontid teeth within a theropod dentary fragment, though these differ from Paronychodon in some details.
Junior synonyms?- Zapsalis was based on a tooth described by Cope (1876) and synonymized with Paronychodon lacustris by Estes (1964). However, Zapsalis falls outside the current concept of Paronychodon in having serrations, and is more robust than teeth of that genus as well. Instead it matches ?Dromaeosaurus morphotype A of Sankey et al. (2002), and is here used as the valid name for that dromaeosaurid.
Tripriodon was based on teeth assigned to two species by Marsh (1889)- the genotype T. coelatus, and T. caperatus. The former is a junior synonym of the multituberculate Meniscoessus robustus (as first shown by Osborn, 1891), while the second belongs to Paronychodon (as first shown by Estes, 1964). Estes was incorrect in synonymizing Tripriodon itself with Paronychodon however, as T. caperatus is only a referred species. This also prevents Marsh's Tripriodontidae from being a theropod family.
Three teeth were originally referred to Paronychodon lacustris (Antunes and Brion, 1988), but later described as the new genus Euronychodon by Antunes and Sigogneau-Russell (1992). This was based on the supposed absence of longitudinal depressions and a median ridge. Yet longitudinal depressions appear to be present in the figure, while identical ridge patterns are seen in some Paronychodon teeth (e.g. Milk River specimens). Euronychodon is thus retained as a junior synonym of Paronychodon here (as in Sige et al., 1997 and Rauhut, 2002). Numerous other teeth were later referred to Euronychodon from the Barremian-Maastrichtian of Eurasia, but they are here listed as Paronychodon or unnamed paronychodontids.
Variation- Sankey et al. (2002) showed there are two morphotypes of Paronychodon teeth. Type A teeth are elongate and straighter, with unconstricted bases. Type B teeth are short and strongly recurved, with constricted bases. They interpreted these are being due to positional variation instead of taxonomic varation, though it should be noted that the holotypes of both Paronychodon lacustris and Tripriodon caperatus are type A teeth. Thus if taxonomic variation proves correct, these names should only be associated with type A teeth. Based on comparison to other theropods, type B teeth may be more posterior in position.
Baszio (1997) noted that half the teeth are flat lingually, and the other half are biconvex. He considered this due to positional variation, with biconvex teeth being from the posterior portion of the jaw. The FABL, BW and FABL/BW measurements of lingually flat teeth were not significantly different from those of biconvex teeth. Again, the holotypes of both Paronychodon lacustris and Tripriodon caperatus are flattened lingually, which should restrict the names to lingually flat teeth if the variation is later shown to be taxonomic.
References- Cope, 1876. Descriptions of some vertebrate remains from the Fort Union Beds of Montana. Proceedings of the Academy of Natural Sciences of Philadelphia. 28, 248-261.
Cope, 1876. On some extinct reptiles and batrachia from the Judith River and Fox Hills Beds of Montana. Proceedings of the Academy of Natural Sciences, Philadelphia. 28, 340-359.
Marsh, 1889. Discovery of Cretaceous mammalia. American Journal of Science, 3rd series. 38, 81-92.
Osborn, 1891. A review of the "Discovery of the Cretaceous Mammalia". The American Naturalist. 25(295), 595-611.
Estes, 1964. Fossil vertebrates from the Late Cretaceous Lance Formation, eastern Wyoming. University of California Publications in Geological Sciences. 49, 1-180.
Russell, 1984. A check list of the families and genera of North American dinosaurs. Syllogeus. 53, 1-35.
Antunes and Brion, 1988. Le Cretace terminal de Beira Litoral, Portugal: remarques stratigraphicques et ecologiques, etude complementaire de Rosasia soutoi (Chelonii, Bothremydidate). Ciencias de Terra. 9, 153-200.
Osmolska and Barsbold, 1990. Troodontidae. In Weishampel, Dodson, and Osmolska, eds.. The Dinosauria, Berkeley: University of California Press: 259-268.
Antunes and Sigogneau-Russell, 1992. La faune de petits dinosaures du Cretace Terminal Portugais. Comun. Serv. Geol. Portugal. 78(1), 49-62.
Zinke and Rauhut, 1994. Small theropods (Dinosauria, Saurischia) from the Upper Jurassic and Lower Cretaceous of the Iberian Peninsula. Berliner geowiss. Abh.. E 13, 163-177.
Rauhut and Zinke, 1995. A description of the Barremian dinosaur fauna from Una with a comparison to that of Las Hoyas. In II International Symposium on Lithographic Limestones, Lleida-Cuenca (Spain), 9th–16th July 1995, Extended Abstracts. 123-126.
Baszio, 1997. Investigations on Canadian dinosaurs: systematic palaeontology of isolated dinosaur teeth from the Latest Cretaceous of south Alberta, Canada. Courier Forschungsinstitut Senckenberg. 196, 33-77.
http://dml.cmnh.org/1997Dec/msg00058.html
Sige, Buscalioni, Duffaud, Gayet, Orth, Rage and Sanz, 1997. Etat des données sur le gisement Crétacé supérieur continental de Champ-Garimond (Gard, Sud de la France). Munchner Geowiss.. 34, 111-130.
Rauhut, 2002. Dinosaur teeth from the Barremian of Una, Province of Cuenca, Spain. Cretaceous Research. 23, 255-263.
Sankey, 2002. Theropod dinosaur diversity in the latest Cretaceous (Maastrichtian) of North America. Journal of Vertebrate Paleontology. 22(3), 103A.
Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.
Hwang, 2005. Phylogenetic patterns of enamel microstructure in dinosaur teeth. Journal of Morphology. 266, 208-240.
Averianov, 2007. Theropod dinosaurs from Late Cretaceous deposits in the northeastern Aral Sea region, Kazakhstan. Cretaceous Research.
Hwang, 2007. Phylogenetic patterns of enamel microstructure in dinosaur teeth. PhD thesis. Columbia University. 274 pp.
Larson, 2008. Diversity and variation of theropod dinosaur teeth from the uppermost Santonian Milk River Formation (Upper Cretaceous), Alberta: a quantitative method supporting identification of the oldest dinosaur tooth assemblage in Canada. Canadian Journal of Earth Science. 45, 1455-1468.
Longrich, 2008. Small theropod teeth from the Lance Formation of Wyoming, USA. in Sankey and Baszio (eds). Vertebrate Microfossil Assemblages: Their Role in Paleontology and Paleobiogeography. Indiana University Press, Bloomington, Ind.. pp. 135-158.
P. lacustris Cope, 1876
Late Campanian, Late Cretaceous
Judith River Formation, Montana, US
Holotype- (AMNH 3018) type A tooth (10 mm)
Referred - (AMNH 8522) type A tooth (13 mm) (Sahni, 1972)
(AMNH 8523) type B tooth (4.8 mm) (Sahni, 1972)
(AMNH 8524) nine teeth (Sahni, 1972)
(AMNH coll.) seven teeth (Sahni, 1972)
(MOR 017) tooth (MOR online)
Early Campanian, Late Cretaceous
Milk River Formation, Alberta, Canada
Material- (UA MR-4: 46) tooth (Baszio, 1997)
(UA MR-47) tooth (Baszio, 1997)
(UA MR-48) type B tooth (Baszio, 1997)
(UA MR-49) type A tooth (Baszio, 1997)
(UA MR-50) type A tooth (Baszio, 1997)
(UA MR-51) type A tooth (Baszio, 1997)
(UA MR-52) tooth (Baszio, 1997)
(UA MR-53) type A tooth (Baszio, 1997)
(UA MR-54) type A tooth (Baszio, 1997)
teeth (Russell, 1935)
Late Campanian, Late Cretaceous
Dinosaur Park Formation of the Judith River Group, Alberta, Saskatchewan, Canada
Material- (RTMP 83.36.8) type A tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 84.36.53) type A tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 86.57.62) type A tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 86.60.114) tooth (Ryan and Russell, 2001)
(RTMP 87.19.65) type B tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 87.112.11) type B tooth (4.3 mm) (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 88.211.66) type A tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 94.12.187) type A tooth (11.5 mm) (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 95.145.53) type B tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 95.177.50) type B tooth (~5.2 mm) (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 95.187.28) type B tooth (5.1 mm) (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 99.55.61) type A tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 99.55.230) type A tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 2000.19.2) type B tooth (5.2 mm) (Sankey, Brinkman, Guenther and Currie, 2002)
nine teeth (Baszio, 1997)
material (Tokaryk, 1988)
Late Campanian, Late Cretaceous
De-na-zin Member of the Kirtland Formation, New Mexico, US
Material- (SMP VP-1354) tooth (Sullivan and Lucas, 2006)
Late Maastrichtian, Late Cretaceous
Frenchman Formation, Saskatchewan, Canada
Material- four teeth (Baszio, 1997)
Diagnosis- (after Sahni, 1972) smaller than P. caperatus and with less defined ridges.
Comments- The holotype has a FABL of 4 mm and a BW of 2.4 mm. It is recurved and flattened lingually with four lingual ridges and six labial ridges. Serrations are absent. It is not from the Hell Creek Formation, contra some sources. Though Sankey et al. (2002) claimed it is not illustrated, Glut (1997) included a photo. Baszio (1997) stated that Paronychodon teeth from the Judith River Group, Milk River Formation and Frenchman Formations were identical. Sullivan and Lucas (2006) in turn stated that SMP VP-1354 from the Kirtland Formation is identical to Milk River teeth. All of these are smaller and with less defined ridges than the Lance Formation species. They can be referred to the species P. lacustris, while the Lance Formation material can be referred to P. caperatus. It's probable other Campanian-Maastrichtian Paronychodon remains (listed as P. sp. below) will be referrable to P. lacustris once they are examined in more detail. Furthermore, this P. lacustris morphotype probably belonged to several different species which differed in non-dental characters, which explains its apparently wide distribution.
References- Cope, 1876. Descriptions of some vertebrate remains from the Fort Union Beds of Montana. Proceedings of the Academy of Natural Sciences of Philadelphia. 28, 248-261.
Russell, 1935. Fauna of the Upper Milk River beds, Southern Alberta. Transactions, Royal Society of Canada. 3(29), 115-127.
Sahni, 1972. The vertebrate fauna of the Judith River Formation, Montana. Bulletin of the AMNH. 147.
Tokaryk, 1988. Preliminary vertebrate faunal list of the Oldman Formation Saskatchewan. Journal of Vertebrate Paleontology. 8(3), 28A.
Baszio, 1997. Investigations on Canadian dinosaurs: systematic palaeontology of isolated dinosaur teeth from the Latest Cretaceous of south Alberta, Canada. Courier Forschungsinstitut Senckenberg. 196, 33-77.
Glut, 1997. Dinosaurs, the Encyclopedia: Mcfarland & Company, Inc., Publishers, 1076pp.
Ryan and Russell, 2001. The dinosaurs of Alberta (exclusive of Aves). in Tanke and Carpenter (eds.). Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie. Indiana University Press, Bloomington, Indiana. pp. 279-297.
Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.
Sullivan and Lucas, 2006. The Kirtlandian land-vertebrate "age" - faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America. New Mexico Museum of Natural History and Science Bulletin. 35, 7-29.
P. caperatus (Marsh, 1889) Olshevsky, 1991
= Tripriodon caperatus Marsh, 1889
= Menisocoessus caperatus (Marsh, 1889)
= Dipriodon caperatus (Marsh, 1889) Currie, Rigby and Sloan, 1990
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (YPM 10624; = YPM 11852) type A tooth
Paratype- ?(YPM 10625) tooth
Referred- (AMNH 21550) tooth (AMNH online)
(AMNH 21551) tooth (AMNH online)
(AMNH 21811) twenty-four teeth (AMNH online)
(AMNH 21812) sixteen teeth and fragments (AMNH online)
(AMNH 21813) sixteen teeth (AMNH online)
(AMNH 21814) three teeth (AMNH online)
?(AMNH 21881) two teeth (AMNH online)
?(AMNH 21882) sixteen teeth (AMNH online)
?(AMNH 21883) tooth (AMNH online)
(AMNH 24930) eighteen teeth (AMNH online)
?(AMNH 24931) tooth (AMNH online)
?(AMNH 24932) four teeth (AMNH online)
(AMNH 27122 in part) sixteen teeth and fragments (AMNH online)
?(AMNH coll.) teeth (Estes, 1964)
(SDSM 12459) two teeth (Whitmore, 1988)
(SDSM 12460) tooth (Whitmore, 1988)
(SDSM 12461) tooth (Whitmore, 1988)
(SDSM 12707) tooth (Whitmore, 1988)
(SDSM 15101) tooth fragment (Whitmore, 1988)
(UA BTB: 134) tooth (Baszio, 1997)
(UA BTB: 136) tooth (Baszio, 1997)
(UA BTB: 137) tooth (Baszio, 1997)
(UA BTB: 138) type A tooth (Baszio, 1997)
(UA BTB: 146) tooth (Baszio, 1997)
?(UA BTB: 166) type B tooth (Baszio, 1997)
(UA BTB: coll.) tooth (Baszio, 1997)
(UCM 38288) (juvenile) tooth (4 mm) (Carpenter, 1982)
(UCM 38459) (juvenile) tooth (1.7 mm) (Carpenter, 1982)
(UCMP 53283) tooth (UCMP online)
(UCMP 73075) teeth (UCMP online)
(UCMP 73076) teeth (UCMP online)
(UCMP 85135) tooth (UCMP online)
(UCMP 124400) three teeth (UCMP online)
(UCMP 124401) four teeth (UCMP online)
(UCMP 186863) teeth (UCMP online)
(UCMP 186919) teeth (UCMP online)
(UCMP 187085-187134) fifty teeth (UCMP online)
(UW 14091) tooth (Breithaupt, 1982)
(UW 14092) tooth (Breithaupt, 1982)
?(YPM 54481) (YPM online)
?(YPM 54490) (YPM online)
(YPM 54999) (YPM online)
(YPM 55021) (YPM online)
(YPM 55022) (YPM online)
(YPM 55498) (YPM online)
?(YPM 55501) (YPM online)
(YPM 55514) (YPM online)
?(YPM 55517) (YPM online)
?(YPM 55527) (YPM online)
(YPM 55528) (YPM online)
?(YPM 55533) (YPM online)
(YPM 55547) (YPM online)
(YPM 55548) (YPM online)
?(YPM 55585) (YPM online)
(YPM 55594) (YPM online)
(YPM 10630) partial type A tooth (Marsh, 1889)
(YPM coll.) tooth (Osborn, 1891)
tooth (Breithaupt, 2001)
Diagnosis- (after Sahni, 1972) larger than P. lacustris and with better defined ridges.
Comments- Marsh (1889) originally described Tripriodon caperatus based on several teeth and tooth fragments, including supposed lower incisors. The holotype is often listed as YPM 11853, but is 11852 in the YPM online catalog. Although Marsh states the specimen came from Laramie beds, the Laramie Formation has not yielded dinosaurs in Wyoming, and the YPM online catalog confirms it was actually found in the Lance Formation. Marsh viewed T. caperatus and the genotype T. coelatus as belonging to a new family Tripriodontidae in his Allotheria, most closely related to Stereognathus (now recognized as a tritylodontid). Tripriodon coelatus is based on a molar which is now thought to belong to Meniscoessus robustus, a species of multituberculate. This was first recognized by Osborn (1891), who believed T. caperatus were lower incisors of Meniscoessus. Osborn also recognized supposed lower incisors of Selenacodon brevis (YPM 10630) and Tripriodon coelatus (YPM coll.) have the same morphology as T. caperatus. Selenacodon brevis is now viewed as a junior synonym of the multituberculate Cimolemys gracilis. Estes (1964) incorrectly believed T. caperatus to be the genotype, and was the first of many authors to synonymize Tripriodon with Paronychodon. He referred the T. caperatus holotype and YPM 10630 to Paronychodon lacustris. Currie et al. (1990) mistakenly listed Dipriodon caperatus, but Dipriodon is another genus now viewed as a synonym of Meniscoessus.
The holotype tooth seems nearly identical to the Paronychodon holotype except for having a shorter crown. It clearly matches tooth type A of Sankey et al. (2002). Baszio (1997) notes these Lance Formation teeth are larger than Paronychodon lacustris from the Milk River, Dinosaur Park, Frenchman and Horseshoe Canyon Formations, with more pronounced wrinkles. They are retained as Paronychodon caperatus here, after Olshevsky (1991). UA BTB 166 is unique in being biconvex with helical ridges.
References- Marsh, 1889. Discovery of Cretaceous mammalia. American Journal of Science, 3rd series. 38, 81-92.
Osborn, 1891. A review of the "Discovery of the Cretaceous Mammalia". The American Naturalist. 25(295), 595-611.
Estes, 1964. Fossil vertebrates from the Late Cretaceous Lance Formation, eastern Wyoming. University of California Publications in Geological Sciences. 49, 1-180.
Breithaupt. 1982. Paleontology and paleoecology of the Lance Formation, (Maastrichtian), east flank of Rick Springs Uplift, Sweetwater County, Wyoming. Contributions to Geology, University of Wyoming. 21(2), 123-151.
Carpenter, 1982. Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod. Contributions to Geology, University of Wyoming. 20(2), 123-134.
Whitmore, 1988. The vertebrate paleontology of Late Cretaceous (Lancian) localities in the Lance Formation, Northern Niobrara County, Wyoming. Unpublished Masters Thesis. South Dakota School of Mines and Technology, Rapid City, South Dakota. 130pp.
Currie, Rigby and Sloan, 1990. Theropod teeth from the Judith River Formation of southern Alberta, Canada. in Carpenter and Currie (eds.). Dinosaur Systematics: Perspectives and Approaches. Cambridge University Press, New York. pp. 107-125.
Olshevsky, 1991. A Revison of the Parainfraclass Archosauria Cope, 1869, Excluding the Advanced Crocodyila. Mesozoic Menanderings #2 (1st printing). iv + 196pp.
Baszio, 1997. Investigations on Canadian dinosaurs: systematic palaeontology of isolated dinosaur teeth from the Latest Cretaceous of south Alberta, Canada. Courier Forschungsinstitut Senckenberg. 196, 33-77.
Breithaupt, 2001. Passport-in-time microvertebrate fossil project at the University of Wyoming Geological Museum: Late Cretaceous Paleontological resources in the public eye. in Santucci and McClelland (eds). Proceedings of the 6th fossil resource conference. United States Department of the interior, National Park Service, Geological Resource Division. 107-112.
Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.
Stokosa 2005. Enamel microstructure variation within the Theropoda. in Carpenter (ed). The Carnivorous Dinosaurs. 163-178.
P. sp. (Kirkland and Parrish, 1995)
Late Albian, Early Cretaceous
Mussentuchit Member of the Cedar Mountain Formation, Utah, US
Material- (CM 72650) tooth fragment (Fiorillo, 1999)
teeth (Kirkland et al., 1997)
partial type A tooth (Garrison et al., 2007)
Comments- Kirkland and Parrish (1995), Kirkland et al. (1997) and Cifelli et al. (1999) list cf. Paronychodon sp. teeth. Fiorillo (1999) describes a tooth fragment possessing a flattened side with longitudinal ridges which he assigns to "Paronychodon", and believes is a dromaeosaurid tooth based on its cross section. Garrison et al. (2007) describes a partial tooth lacking serrations and a flattened side with three ridges, referring it to cf. Paronychodon sp..
References- Kirkland and Parrish, 1995. Theropod teeth from the Lower Cretaceous of Utah. Journal of Vertebrate Paleontology. 15(3), 39A.
Kirkland, Britt, Burge, Carpenter, Cifelli, DeCourten, Eaton, Hasiotis and Lawton, 1997. Lower to Middle Cretaceous dinosaur faunas of the Central Colorado Plateau: a key to understanding 35 million years of tectonics, sedimentology, evolution, and biogeography. Brigham Young University Geology Studies. 42, 69-103.
Cifelli, Nydam, Gardner, Weil, Eaton, Kirkland, Madsen, 1999. Medial Cretaceous vertebrates from the Cedar Mountain Formation, Emery County, Utah: the Mussentuchit Local Fauna. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 219-242.
Fiorillo, 1999. Non-mammalian microvertebrate remains from the Robison Eggshell site, Cedar Mountain Formation (Lower Cretaceous), Emery County, Utah. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 259-268.
Garrison, Brinkman, Nichols, Layer, Burge and Thayn, 2007. A multidisciplinary study of the Lower Cretaceous Cedar Mountain Formation, Mussentuchit Wash, Utah: a determination of the paleoenvironment and paleoecology of the Eolambia caroljonesa dinosaur quarry. Cretaceous Research. 28, 461-494.
P. sp. (Kirkland, Britt, Burge, Carpenter, Cifelli, DeCourten, Eaton, Hasiotis and Lawton, 1997)
Late Cenomanian, Late Cretaceous
Dakota Formation, Utah, US
Material- teeth
Comments- These were listed as cf. Paronychodon sp. by Kirkland et al. (1997).
Reference- Kirkland, Britt, Burge, Carpenter, Cifelli, DeCourten, Eaton, Hasiotis and Lawton, 1997. Lower to Middle Cretaceous dinosaur faunas of the Central Colorado Plateau: a key to understanding 35 million years of tectonics, sedimentology, evolution, and biogeography. Brigham Young University Geology Studies. 42, 69-103.
P. sp. (Kirkland, Lucas and Estep, 1998)
Middle-Late Turonian, Late Cretaceous
Smoky Hollow Member of the Straight Cliffs Formation, Utah, US
Material- (MNA 995) tooth (Parrish, 1999)
(OMNH 24451) tooth (Parrish, 1999)
(OMNH 25415) tooth (Parrish, 1999)
Comments- These were listed as cf. Paronychodon by Kirkland et al. (1998) and Parrish (1999).
References- Kirkland, Lucas and Estep, 1998. Cretaceous dinosaurs of the Colorado Plateau. in Lucas, Kirkland and Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. 14, 79-89.
Parrish, 1999. Dinosaur teeth from the Upper Cretaceous (Turonian-. Judithian) of southern Utah. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 319-321.
P. sp. (Kirkland, Lucas and Estep, 1998)
Coniacian-Santonian, Late Cretaceous
John Henry Member of the Straight Cliffs Formation, Utah, US
Comments- This is listed as cf. Paronychodon sp. by Kirkland et al. (1998).
Reference- Kirkland, Lucas and Estep, 1998. Cretaceous dinosaurs of the Colorado Plateau. in Lucas, Kirkland and Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. 14, 79-89.
P. sp. (Kirkland, Lucas and Estep, 1998)
Early Campanian, Late Cretaceous
Wahweap Formation, Utah
Comments- This is listed as cf. Paronychodon sp. by Kirkland et al. (1998).
Reference- Kirkland, Lucas and Estep, 1998. Cretaceous dinosaurs of the Colorado Plateau. in Lucas, Kirkland and Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. 14, 79-89.
P. sp. (Ryan and Russell, 2001)
Late Campanian, Late Cretaceous
Foremost Formation of the Judith River Group, Alberta, Canada
Material- (RTMP coll.) teeth
Reference- Ryan and Russell, 2001. The dinosaurs of Alberta (exclusive of Aves). in Tanke and Carpenter (eds.). Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie. Indiana University Press, Bloomington, Indiana. pp. 279-297.
P. sp. (Ryan and Russell, 2001)
Late Campanian, Late Cretaceous
Oldman Formation of the Judith River Group, Alberta, Canada
Material- (RTMP 92.77.6) tooth
(RTMP coll.) teeth
Reference- Ryan and Russell, 2001. The dinosaurs of Alberta (exclusive of Aves). in Tanke and Carpenter (eds.). Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie. Indiana University Press, Bloomington, Indiana. pp. 279-297.
P? sp. (Armstrong-Zeigler, 1978)
Late Campanian, Late Cretaceous
Fruitland Formation, New Mexico, US
Material- (MNA Pl. 1627) nine teeth (Armstrong-Ziegler, 1978)
Comments- These were listed as Paronychodon lacustris by Armstrong-Ziegler (1978), but later as Dromaeosauridae incertae sedis by Lucas et al. (1987).
References- Armstrong-Zeigler, 1978. An aniliid snake and associated vertebrates from the Campanian of New Mexico. Journal of Paleontology. 52(2), 480-483.
Lucas, Mateer, Hunt and O’Neill, 1987. Dinosaurs, the age of the Fruitland and Kirtland Formations, and the Cretaceous-Tertiary boundary in the San Juan Basin, New Mexico. in Fassett and Rigby (eds). The Cretaceous-Tertiary Boundary in the San Juan and Raton Basins, New Mexico and Colorado. The Geological Society of America Special Paper. 209, 35-50.
P. sp. (Kirkland, Lucas and Estep, 1998)
Late Campanian, Late Cretaceous
Kaiparowitz Formation, Utah, US
Material- (UCM 8304) tooth (Parrish, 1999)
(OMNH 24161) tooth (Parrish, 1999)
(OMNH 24164) tooth (Parrish, 1999)
Comments- These were listed as cf. Paronychodon by Kirkland et al. (1998) and Parrish (1999).
Reference- Kirkland, Lucas and Estep, 1998. Cretaceous dinosaurs of the Colorado Plateau. in Lucas, Kirkland and Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. 14, 79-89.
Parrish, 1999. Dinosaur teeth from the Upper Cretaceous (Turonian-. Judithian) of southern Utah. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 319-321.
Late Campanian, Late Cretaceous
Mesaverde Formation, Wyoming, US
Material- (AMNH 12881) tooth
(AMNH 12882) tooth
(UCMP 120848) tooth (UCMP online)
(UW 34819) tooth
References- Breithaupt, 1985. Nonmammalian vertebrates faunas from the late Cretaceous of Wyoming. Thirty-Sixth Annual Field Conference-1985, Wyoming Geological Association Guidebook. 159-175.
Demar and Breithaupt, 2006. The nonmammalian vertebrate microfossil assemblages of the Mesaverde Formation (Upper Cretaceous, Campanian) of the Wind River and Bighorn Basin, Wyoming. in Lucas and Sullivan (eds). Late Cretaceous Vertebrates from the Western Interior. New Mexico Museum of Natural History & Science, Bulletin. 35, 33-53.
P. sp. (MOR online)
Late Campanian, Late Cretaceous
Two Medicine Formation, Montana, US
Material- (MOR 221) tooth (MOR online)
(MOR 505) tooth (MOR online)
(MOR 516) teeth (MOR online)
P. sp. (Hoganson and Erickson, 2004)
Maastrichtian, Late Cretaceous
Fox Hills Formation, North Dakota, US
Reference- Hoganson and Erickson, 2004. Paleoecological implications of the Fox Hills Formation (Maastrichtian) reptilian and amphibian fauna from south-central North Dakota. Geological Society of America Rocky Mountain and Cordilleran Sections Annual Meeting, Boise, Idaho, Abstracts with Programs. 36(4), 80.
P. sp. (Langston, Standhardt and Stevens, 1989)
Early Maastrichtian, Late Cretaceous
Aguja Formation, Texas, US
Material- (LSU 113:1310) type A tooth (~5.5 mm)
(LSU 113:1311) type A tooth
(LSU 113:5107) type A tooth (~3 mm)
(LSU 113:5993) type A tooth (~2.5 mm)
(LSU 113:5996) type A tooth
References- Langston, Standhardt and Stevens, 1989. Fossil vertebrate collecting in the Big Bend - History and retrospective. in Vertebrate Paleontology, Biostratigraphy and Depositional Environments, Latest Cretaceous and Tertiary, Big Bend Area, Texas. Guidebook Field Trip Numbers 1 a, B, and 49th Annual Meeting of the Society of Vertebrate Paleontology, Austin, Texas, 29 October - 1 November 1989. 11-21.
Sankey, Standhardt and Schiebout, 2005. Theropod teeth from the Upper Cretaceous (Campanian-Maastrichtian), Big Bend National Park, Texas. in Carpenter (ed). The Carnivorous Dinosaurs. 127-152.
P. sp. (Baszio, 1997)
Early Maastrichtian, Late Cretaceous
Horseshoe Canyon Formation, Alberta, Canada
Material- (RTMP 97.39.6) partial type A tooth (Ryan, Currie, Gardner, Vickaryous and Lavigne, 1998)
(RTMP 1041) tooth (Baszio, 1997)
Comments- RTMP 97.39.6 is flat lingually and convex labially. It has eight lingual ridges and ten labial ones.
References- Baszio, 1997. Investigations on Canadian dinosaurs: systematic palaeontology of isolated dinosaur teeth from the Latest Cretaceous of south Alberta, Canada. Courier Forschungsinstitut Senckenberg. 196, 33-77.
Ryan, Currie, Gardner and Livigne, 1997. Baby hadrosaurid material associated with an unusually high abundance of troodontid teeth from the Horseshoe Canyon Formation (Early Maastrichtian), Alberta, Canada. Journal of Vertebrate Paleontology. 17(3), 72A.
Ryan, Currie, Gardner, Vickaryous and Lavigne, 1998. Baby hadrosaurid material associated with an unusually high abundance of Troodon teeth from the Horseshoe Canyon Formation, Upper Cretaceous, Alberta, Canada. Gaia. 15, 123-133.
P. sp. (Estes, Berberian and Mesozoely, 1969)
Late Maastrichtian, Late Cretaceous
Hell Creek Formation, Montana, South Dakota, US
Material- (AMNH 21555) tooth (AMNH online)
(MCZ 3645) two teeth (Estes, Berberian and Mesozoely, 1969)
(UCMP 119922) tooth (UCMP online)
(UCMP 119923) tooth (UCMP online)
(UCMP 120076) tooth (UCMP online)
(UCMP 120192) tooth (UCMP online)
(UCMP 120254) tooth fragment (UCMP online)
(UCMP 123341) tooth (UCMP online)
(UCMP 124405) tooth (UCMP online)
(UCMP 124990) (juvenile) type B tooth (3.4 mm) (Carpenter, 1982)
(UCMP 124991) (juvenile) tooth (4.8 mm) (Carpenter, 1982)
(UCMP 124992) (juvenile) tooth (4.3 mm) (Carpenter, 1982)
(UCMP 128764) three teeth (UCMP online)
(UCMP 186867) teeth (UCMP online)
(UCMP 186876) teeth (UCMP online)
(UCMP 186879) teeth (UCMP online)
(UCMP 186884) teeth (UCMP online)
(UCMP 186898) teeth (UCMP online)
(UCMP 186910) teeth (UCMP online)
(UCMP 186923) teeth (UCMP online)
(UCMP 187080) tooth (UCMP online)
(UCMP 187081) tooth (UCMP online)
(UCMP 187082) tooth (UCMP online)
(UCMP 187135-187156) twenty-two teeth (UCMP online)
(YPM PU 20571) (Estes, Berberian and Mesozoely, 1969)
teeth (Stenerson and O'Conner, 1994)
teeth (Triebold, 1997)
References- Estes, Berberian and Mesozoely, 1969. Lower vertebrates from the Late Cretaceous Hell Creek Formation, McCone County, Montana. Breviora. 337, 1-33.
Carpenter, 1982. Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod. Contributions to Geology, University of Wyoming. 20(2), 123-134.
Stenerson and O'Conner, 1994. The Late Cretaceous Hell Creek Formation of Northwestern South Dakota and its Fauna. MAPS Digest. 17(4), 108-120.
Triebold, 1997. The Sandy Site: Small Dinosaurs from the Hell Creek Formation of South Dakota. in Wolberg, Stump and Rosenberg (eds). Dinofest International, Proceedings of a Symposium sponsered by Arizona State University. A Publication of The Academy of Natural Sciences. 245-248.
P. sp. (Wroblewski, 1995)
Late Maastrichtian, Late Cretaceous
Ferris Formation, Wyoming, US
Material- teeth
References- Wroblewski, 1995. First report of changes in Lower Vertebrate Faunas across the Cretaceous-Tertiary boundary, Western Hanna Basin, Wyoming. Journal of Vertebrate Paleontology. 15(3), 61A.
Wroblewski, 1998. Changing paleoenvironments and paleofaunas across the K-T boundary, Ferris Formation, Southcentral Wyoming. Tate Geological Museum, Casper College, Casper Wyoming. Tate ’98. Life in the Cretaceous. 53-70.
P. sp. indet.
Cretaceous
Montana, US
Material- (AMNH 2134) tooth (AMNH online)
?Cretaceous
US
Material- (YPM 56974) (YPM online)
P. sp. nov. (Rauhut and Zinke, 1995)
Late Barremian, Early Cretaceous
Una (= Calizas de La Huergina) Formation, Spain
Material- (IPFUB Una Th 53, 55-61, 69) thirteen teeth (to 6 mm) (Rauhut and Zinke, 1995)
(IPFUB Una Th 69) tooth (Rauhut, 2002)
Comments- These teeth are slightly recurved, with no mesial or distal serrations. They have a flattened lingual side with a central ridge, while some specimens also have a weak labial ridge. Some teeth have a slight basal constriction. Rauhut and Zinke (1995) originally referred these specimens to cf. Euronychodon sp., though they were later referred to cf. Paronychodon sp. by Rauhut (2002).
References- Rauhut and Zinke, 1995. A description of the Barremian dinosaur fauna from Una with a comparison to that of Las Hoyas. In II International Symposium on Lithographic Limestones, Lleida-Cuenca (Spain), 9th–16th July 1995, Extended Abstracts. 123-126.
Rauhut, 2002. Microrestos de dinosaurios del Cretácico inferior de Uña, España. Resumenes de las XVIII Jornadas Argentinas de Paleontología de Vertebrados. Bahia Blanca, Argentina. 36.
Rauhut, 2002. Dinosaur teeth from the Barremian of Una, Province of Cuenca, Spain. Cretaceous Research. 23, 255-263.
P? sp. (Averianov, Leshchinskiy, Skutschas, Fayngertz and Rezvyi, 2004)
Aptian-Albian, Early Cretaceous
Ilek (=Shestakovo) Formation, Russia
Material- teeth
Comments- Referred to cf. Paronychodon.
Reference- Averianov, Leshchinskiy, Skutschas, Fayngertz and Rezvyi, 2004. Dinosaurs from the Early Cretaceous Ilek Formations in West Siberia, Russia. 2nd EAVP Meeting. July 19-24, 2004. Brno, Czech Republic. Abstracts of papers and posters with program, Excursion Guidebook. pg 6.
P. sp. (Averianov, 2007)
Middle Albian-Early Cenomanian, Early-Late Cretaceous
Khodzhakul Formation, Uzbekistan
Material- teeth
Reference- Averianov, 2007. Theropod dinosaurs from Late Cretaceous deposits in the northeastern Aral Sea region, Kazakhstan. Cretaceous Research.
P. asiaticus (Nessov, 1995) new comb.
= Euronychodon asiaticus Nessov, 1995
Mid-Late Turonian, Late Cretaceous
Bissekty Formation, Uzbekistan
Holotype- (CCMGE N 9/12454) tooth
Paratypes- (CCMGE coll.) six teeth
Diagnosis- provisionally indeterminate within Paronychodon.
Comments- These teeth were first described as Paronychodon cf. lacustris by Nessov (1985, 1986). They are described as curved with a flattened or sometimes weakly concave lingual side with a few ridges. The labial side has 14 or more ridges. Nessov (1995) distinguished it from Euronychodon portucalensis based on the presence of numerous labial grooves, but the latter are seen in a paratype of E. portucalensis.
References- Nessov, 1985. [New mammals of the Cretaceous of the Kyzylkum]. Vyestnik Lyeningradskogo univyersityeta, Biologiya. 17, 8-18.
Nessov, 1986. [The first discovery of the Late Cretaceous bird Ichthyornis in the Old World and some other bones of birds from the Cretaceous and Paleogene of Middle Asia]. Trudy Zoologichyeskogo Instituta AN SSSR. 147, 31-38.
Nessov, 1995. Dinozavri severnoi Yevrasii: Novye dannye o sostave kompleksov, ekologii i paleobiogeografii [Dinosaurs of Northern Eurasia: new data about assemblages, ecology and paleobiogeography], Scientific Research Institute of the Earth's Crust, St. Petersburg State University, St. Petersburg, Russia: 156 pp. + 14 pl. [in Russian with short English, German, and French abstracts].
Averianov, 2007. Theropod dinosaurs from Late Cretaceous deposits in the northeastern Aral Sea region, Kazakhstan. Cretaceous Research.
P. sp. (Garcia, Duffaud, Feist, Marandat, Tambareau, Villatte and Sige, 2000)
Turonian-Maastrichtian, Late Cretaceous
La Nueve, Aix, France
Material- (LNE-D01) tooth
Reference- Garcia, Duffaud, Feist, Marandat, Tambareau, Villatte and Sige, 2000. La neuve, gisement a plantes, invertebres et vertebres du Begudien (Senonien superieur continental) du bassin d’Aix-en-Provence. Geodiversitas. 22(3), 326-348.
P? sp. (Sige, Buscalioni, Duffaud, Gayet, Orth, Rage and Sanz, 1997)
Campanian, Late Cretaceous
unnamed unit, Champ-Garimond, Gard, France
Material- teeth
Comments- These differ from most Paronychodon specimens in lacking carinae. They were assigned to Paronychodon by Sige et al. (1997).
Reference- Sige, Buscalioni, Duffaud, Gayet, Orth, Rage and Sanz, 1997. Etat des données sur le gisement Crétacé supérieur continental de Champ-Garimond (Gard, Sud de la France). Munchner Geowiss.. 34, 111-130.
P? sp. (Le Loeuff, 1992)
Late Campanian, Late Cretaceous
Vitoria Formation, Spain
Material- teeth
Comments- These were listed as cf. Euronychodon sp. by Suberbiola et al. (2000).
References- Le Loeuff, 1992. Les vertébrés continentaux du Crétacé supérieur d'Europe: Paléoécologie, Biostratigraphie et Paléobiogéographie. Mémoires des Sciences de la Terre de l'Université Pierre et Marie Curie, Paris, (Thèse d'Université, non publié). 92-3, 273 pp.
Astibia, Murelaga, Pereda-Suberbiola, Elorza and Gomez-Alday, 1999. Taphonomy and palaeoecology of the Upper Cretaceous continental vertebrate-bearing beds of the Laño Quarry (Iberian Peninsula). Est. Mus. Cienc. Nat. de Alava. 14 (Núm. Espec. 1), 43-104.
Pereda-Suberbiola, Asibia, Murelaga, Elzorza and Gomez-Alday, 2000. Taphonomy of the Late Cretaceous dinosaur-bearing beds of the Lano Quarry (Iberian Peninsula). Palaeogeography, Palaeoclimatology, Palaeoecology. 157, 247-275.
P. portucalensis (Antunes and Sigogneau-Russell, 1991) new comb.
= Euronychodon portucalensis Antunes and Sigogneau-Russell, 1991
Late Campanian-Early Maastrichtian, Late Cretaceous
unnamed unit, Taviero, Portugal
Holotype- (CEPUNL TV 20) type A tooth (1.8 mm)
Paratypes- (CEPUNL TV 18) type B tooth
(CEPUNL TV 19) tooth
Diagnosis- provisionally indeterminate within Paronychodon.
Comments- These teeth were originally referred to Paronychodon lacustris (Antunes and Brion, 1988). They were later described as the new genus Euronychodon by Antunes and Sigogneau-Russell (1992) based on the supposed absence of longitudinal depressions and a median ridge. Yet longitudinal depressions appear to be present in the figure, while identical ridge patterns are seen in some Paronychodon teeth (e.g. Milk River specimens). Euronychodon is thus retained as a junior synonym of Paronychodon here (as in Rauhut, 2002).
References- Antunes and Brion, 1988. Le Cretace terminal de Beira Litoral, Portugal: remarques stratigraphicques et ecologiques, etude complementaire de Rosasia soutoi (Chelonii, Bothremydidate). Ciencias de Terra. 9, 153-200.
Antunes and Sigogneau-Russell, 1992. La faune de petits dinosaures du Cretace Terminal Portugais. Comun. Serv. Geol. Portugal. 78(1), 49-62.
Rauhut, 2002. Dinosaur teeth from the Barremian of Una, Province of Cuenca, Spain. Cretaceous Research. 23, 255-263.
P. sp. nov. (Csiki and Grigorescu, 1998)
Late Maastrichtian, Late Cretaceous
Sinpetru Beds, Romania
Material- (FGGUB R.1431) type A tooth (5.1 mm) (Csiki and Grigorescu, 1998)
type A tooth (Codrea, Smith, Dica, Folie, Garcia, Godefroit and Van Itterbeecke, 2002)
teeth (Codrea, Smith, Dica, Folie, Garcia, Godefroit and Van Itterbeecke, 2002)
Comments- FGGUB R.1431 differs from most Paronychodon specimens in having only two lingual grooves and lacking labial grooves. A tooth morphotype illustrated by Codrea et al. (2002) is elongate and strongly recurved, lacks serrations, is not as asymmetrical as Paronychodon, and is said to lack ridges or grooves. Csiki and Grigorescu refer FGGUB R.1431 to cf. Euronychodon, while Codrea et al. refer to their teeth as Euronychodon morphotype.
References- Csiki and Grigorescu, 1998. Small theropods from the Late Cretaceous of the Hateg Basin (Western Romania) - an unexpected diversity at the top of the food chain. Oryctos. 1, 87-104.
Codrea, Smith, Dica, Folie, Garcia, Godefroit and Van Itterbeecke, 2002. Dinosaur egg nests, mammals and other vertebrates from a new Maastrichtian site of the Hateg Basin (Romania). C. R. Palevol. V. 1, p. 173-180.
P. sp. (Codrea, Smith, Dica, Folie, Garcia, Godefroit and Van Itterbeecke, 2002)
Late Maastrichtian, Late Cretaceous
Sinpetru Beds, Romania
Material- partial type A tooth (Codrea, Smith, Dica, Folie, Garcia, Godefroit and Van Itterbeecke, 2002)
teeth (Codrea, Smith, Dica, Folie, Garcia, Godefroit and Van Itterbeecke, 2002)
Comments- This tooth type is referred to the Paronychodon morphotype by Codrea et al.(2002). It lacks serrations, is flat on one side, and has several longitudinal ridges.
Reference- Codrea, Smith, Dica, Folie, Garcia, Godefroit and Van Itterbeecke, 2002. Dinosaur egg nests, mammals and other vertebrates from a new Maastrichtian site of the Hateg Basin (Romania). C. R. Palevol. V. 1, p. 173-180.

Urbacodon Averianov and Sues, 2007
U. itemirensis Averianov and Sues, 2007
Cenomanian, Late Cretaceous
Dzharakuduk Formation, Uzbekistan
Holotype- (ZIN PH 944/16) dentary, six teeth
Reference- Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.
U. sp. indet. (Averianov and Sues, 2007)
Mid-Late Turonian, Late Cretaceous
Bissekty Formation, Uzbekistan
Material- (CCMGE 2/11822) tooth
(CCMGE 71/12455) premaxillary tooth
(CCMGE 466/12457) braincase fragment
(CCMGE 475/12457) mid caudal vertebra
(ZIN PH 256/16) anterior dentary tooth
(ZIN PH 1899/16) posterior maxillary or dentary tooth
(ZIN PO 4608) dentary fragment, tooth
cervical vertebrae, dorsal vertebrae, distal caudal vertebrae, metacarpal I, metatarsal III
Comments- Nessov (1992, 1997) identified ZIN PO 4608 as an ichthyornithine. Nessov (1993) identified CCMGE 71/12455 as Deinonychosauria or Mammalia. Nessov (1995) identified CCMGE 2/11822 as Theropoda indet., CCMGE 466/12457 as possibly Dromaeosauridae, and CCMGE 475/12457 as possibly Ornithomimidae. Averianov and Sues (2007) reidentified these and additional specimens as being troodontid, assigned to Urbacodon sp. due to the resemblence of the dental and dentary remains to the U. itemirensis holotype.
References- Nessov, 1992. [Review of localities and remains of Mesozoic and Paleogene birds of the USSR and the description of new findings.] Russkii Ornitologicheskii Zhurnal 1:7–50. [Russian]
Nessov, L. A. 1993. [New Mesozoic mammals from Middle Asia and Kazakhstan and comments on the evolution of mammal faunas of the Cretaceous coastal plains of Asia.] Trudy Zoologicheskogo Instituta RAN 249:105–133. [Russian]
Nessov, 1995. [Dinosaurs of Northern Eurasia: New Data about Assemblages, Ecology, and Paleobiogeography.] Izdatel’stvo Sankt-Peterburgskogo Universiteta, Saint Petersburg. 156 pp. [Russian]
Nessov, L. A. 1997. [Cretaceous Nonmarine Vertebrates of Northern Eurasia.] (Posthumous edition by L. B. Golovneva and A. O. Averianov.) Izdatel’stvo Sankt-Peterburgskogo Universiteta, Saint Petersburg, 218 pp. [Russian]
Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.

undescribed Troodontidae (Bolotsky and Moiseenko, 1988)
Late Maastrichtian, Late Cretaceous
Udurchukan Formation of the Tsagayan Group, Russia
Material- teeth
Comments- These teeth have been noted as Troodontidae indet. (Bolotsky and Moiseenko, 1988; Nessov and Golovneva, 1990; Nessov, 1995), Troodon cf. formosus (Moiseenko et al., 1997) and Troodon sp. (Alifanov and Bolotsky, 2002), but have yet to be described.
References- Bolotsky and Moiseenko, 1988. [On Dinosaurs of the Amur River Region.] Amur KNII DVO AN SSSR, Blagoveshchensk, 38pp. [Russian]
Nessov and Golovneva, 1990. [History of the flora, vertebrates and climate in the late Senonian of the north-eastern Koriak Uplands]; pp. 191–212 in V. A. Krasilov (ed.), [Continental Cretaceous of the USSR.] Dal’nevostochnoe Otdelenie AN SSSR, Vladivostok. [Russian]
Nessov, 1995. Dinosaurs of nothern Eurasia: new data about assemblages, ecology, and paleobiogeography. Institute for Scientific Research on the Earth's Crust, St. Petersburg State University, St. Petersburg 1-156.
Moiseenko, Sorokin and Bolotsky, 1997. [Fossil Reptiles of the Amur River Area.] Amurskii Nauchnyi Tsentr DVO RAN, Khabarovsk, 54 pp. [Russian]
Alifanov and Bolotsky, 2002. New data about the assemblages of the Upper Cretaceous carnivorous dinosaurs (Theropoda) from the Amur Region; pp. 25–26 in G. L. Kirillova (ed.), Fourth International Symposium of IGCP 434: Cretaceous Continental Margin of East Asia: Stratigraphy, Sedimentation, and Tectonic, Program and Abstracts. UNESCO-IUGS-IGCP, Khabarovsk.
Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.

undescribed possible troodontid (Brett-Surman, Jabo, Kroehler, Carrano and Kvale, 2005)
Kimmeridgian-Early Tithonian, Late Jurassic
Morrison Formation, Wyoming, US
Material- tooth
Comments- Brett-Surman et al. (2005) state this tooth has troodontid-like serrations. It may belong to Koparion or the taxon represented by WDC DML0001.
Reference- Brett-Surman, Jabo, Kroehler, Carrano and Kvale, 2005. A new microvertebrate assemblage from the Upper Jurassic Morrison Formation, including mammals, theropods, and sphenodontians. Journal of Vertebrate Paleontology. 25(3), 39A.

undescribed possible Troodontidae (Chure, 1995)
Late Kimmeridgian, Late Jurassic
Brushy Basin Member of the Morrison Formation, Utah, US
Material- teeth
Reference- Chure, 1995. The teeth of small theropods from the Morrison Formation (Upper Jurassic: Kimmeridgian), UT. Journal of Vertebrate Paleontology. 15(3), 23A.

undescribed Troodontidae (Cifelli, Gardner, Nydam and Brinkman, 1997)
Early-Middle Albian, Early Cretaceous
Antlers Formation, Oklahoma, US
Reference- Cifelli, Gardner, Nydam and Brinkman, 1997. Additions to the vertebrate fauna of the Antlers Formation (Lower Cretaceous), southeastern Oklahoma. Oklahoma Geology Notes. 57(4), 124-131.

undescribed possible Troodontidae (Kirkland, Britt, Burge, Carpenter, Cifelli, DeCourten, Eaton, Hasiotis and Lawton, 1997)
Late Albian, Early Cretaceous
Mussentuchit Member of the Cedar Mountain Formation, Utah, US
Material- teeth
Comments- These are identified as cf. Troodon sp. in Kirkland et al. (1997), and Troodontidae gen. et sp. indet. by Cifelli et al. (1999). They are probably the troodontid teeth mentioned by Parrish and Eaton (1991) and Kirkland and Parrish (1995) from the Cedar Mountain Formation.
References- Parrish and Eaton, 1991. Diversity and Evolution of Dinosaurs in the Cretaceous of the Kaipirowits Plateau, Utah. Journal of Vertebrate Paleontology. 11(3), 50A.
Kirkland and Parrish, 1995. Theropod teeth from the Lower Cretaceous of Utah. Journal of Vertebrate Paleontology. 15(3), 39A.
Kirkland, Britt, Burge, Carpenter, Cifelli, DeCourten, Eaton, Hasiotis and Lawton, 1997. Lower to Middle Cretaceous dinosaur faunas of the Central Colorado Plateau: a key to understanding 35 million years of tectonics, sedimentology, evolution, and biogeography. Brigham Young University Geology Studies. 42, 69-103.
Cifelli, Nydam, Gardner, Weil, Eaton, Kirkland, Madsen, 1999. Medial Cretaceous vertebrates from the Cedar Mountain Formation, Emery County, Utah: the Mussentuchit Local Fauna. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 219-242.

undescribed Troodontidae (Kirkland, Britt, Burge, Carpenter, Cifelli, DeCourten, Eaton, Hasiotis and Lawton, 1997)
Late Cenomanian, Late Cretaceous
Dakota Formation, Utah, US
Material- teeth
Comments- These are identified as cf. Troodon sp. in Kirkland et al. (1997) and later references.
Reference- Kirkland, Britt, Burge, Carpenter, Cifelli, DeCourten, Eaton, Hasiotis and Lawton, 1997. Lower to Middle Cretaceous dinosaur faunas of the Central Colorado Plateau: a key to understanding 35 million years of tectonics, sedimentology, evolution, and biogeography. Brigham Young University Geology Studies. 42, 69-103.
Eaton, Cifelli, Hutchison, Kirkland and Parrish, 1999. Cretaceous vertebrate faunas from the Kaiparowits Plateau, south central Utah. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 345-353.

undescribed troodontid (Eaton, 1999)
Late Cenomanian-Early Turonian?, Early-Late Cretaceous
Iron Springs Formation, Utah, US
Material- teeth
Reference- Eaton, 1999. Vertebrate paleontology of the Iron Springs Formation, Upper Cretaceous, southwestern Utah. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 339-343.

undescribed Troodontidae (Kirkland, Lucas and Estep, 1998)
Middle-Late Turonian, Late Cretaceous
Smoky Hollow Member of the Straight Cliffs Formation, Utah, US
Material- teeth
Reference- Kirkland, Lucas and Estep, 1998. Cretaceous dinosaurs of the Colorado Plateau. in Lucas, Kirkland and Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. 14, 79-89.

undescribed Troodontidae (Kirkland, Lucas and Estep 1998)
Coniacian-Santonian, Late Cretaceous
John Henry Member of the Straight Cliffs Formation, Utah, US
Reference- Kirkland, Lucas and Estep, 1998. Cretaceous dinosaurs of the Colorado Plateau. in Lucas, Kirkland and Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. 14, 79-89.

undescribed Troodontidae (Kirkland, Lucas and Estep 1998)
Early Campanian, Late Cretaceous
Wahweap Formation, Utah, US
Material- (OMNH 21988) tooth (Parrish, 1999)
(OMNH 24237) tooth (Parrish, 1999)
Comments- Parrish (1999) referred two teeth to cf. Troodon. Eaton et al. listed them as Troodon sp..
References- Kirkland, Lucas and Estep, 1998. Cretaceous dinosaurs of the Colorado Plateau. in Lucas, Kirkland and Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. 14, 79-89.
Eaton, Cifelli, Hutchison, Kirkland and Parrish, 1999. Cretaceous vertebrate faunas from the Kaiparowits Plateau, south central Utah. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 345-353.
Parrish, 1999. Dinosaur teeth from the Upper Cretaceous (Turonian-. Judithian) of southern Utah. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 319-321.

undescribed Troodontidae (www.paleofile.com)
Late Campanian, Late Cretaceous
Fruitland Formation, New Mexico, US
Material- (MNA Pl. 1624) several teeth
Comments- Ford (www.paleofile.com) lists this specimen as being in Armstrong-Ziegler (1978), but neither it nor troodontids are explicitely mentioned in that paper.
Reference- Armstrong-Ziegler, 1978. An Aniliid Snake and Associated Vertebrates from the Campanian of New Mexico: Journal of Paleontology, v. 52, n. 2, p. 480-483.

undescribed Troodontidae (Parrish and Eaton, 1991)
Late Campanian, Late Cretaceous
Kaiparowitz Formation, Utah, US
Material- (OMNH 21958) tooth (Parrish, 1999)
(UCM 83253) tooth (Parrish, 1999)
(UCM 8659; in part) tooth (Parrish, 1999)
References- Parrish and Eaton, 1991. Diversity and Evolution of Dinosaurs in the Cretaceous of the Kaipirowits Plateau, Utah. Journal of Vertebrate Paleontology. 11(3), 50A.
Parrish, 1999. Dinosaur teeth from the Upper Cretaceous (Turonian-. Judithian) of southern Utah. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 319-321.

undescribed troodontid (Lehman, 1981)
Late Campanian, Late Cretaceous
Lower Kirkland Formation, New Mexico, US
Material- (UNM FKK-014) teeth
Reference- Lehman, 1981. The Alamo Wash Local Fauna: a new look at the old Ojo Alamo Fauna. in Lucas, Rigby and Kues (eds.). Advances in San Juan Basin Paleontology. New Mexico University Press, Albuquerque, New Mexico. 189-221.

undescribed Troodontidae (Kirkland, Lucas and Estep, 1998)
Late Maastrichtian, Late Cretaceous
North Horn Formation, Utah, US
Material- (OMNH and/or UMNH coll.) teeth
Comments- Kirkland et al. (1998) and Cifelli et al. (1999) mention Troodontidae gen. et sp. indet. from the North Horn Formation.
References- Kirkland, Lucas and Estep, 1998. Cretaceous dinosaurs of the Colorado Plateau. in Lucas, Kirkland and Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. 14, 79-89.
Cifelli, Nydam, Eaton, Gardner, Kirkland, 1999. Vertebrate faunas of the North Horn Formation (Upper Cretaceous-lower Paleocene), Emery and Sanpete counties, Utah. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological Survey, Miscellaneous Publication. 99-1, 378-388.

unnamed possible troodontid (Huene, 1934)
Santonian-Campanian, Late Cretaceous
Pallacio (Guichon) Formation, Uruguay
Material- tooth
Comments- This was listed on www.paleofile.com as a troodontid. It is preseumably tooth B of Huene (1934), identified by him as an ornithomimid.
Reference- Huene. 1934. Neue Saurier-Zähne aus der Kreide von Uruguay [New saurian teeth from the Cretaceous of Uruguay]. Centralblatt für Mineralogie, Geologie und Paläontologie, Abteilung B: Geologie und Paläontologie. 1934(4),183-189.

undescribed Troodontidae (Bertini and Franco-Rosas, 2001)
Turonian-Late Maastrichtian, Late Cretaceous
Adamantina and Marilia Formations, Bauru Group, Brazil
Material- teeth
Reference- Bertini and Franco-Rosas, 2001. Scanning electron microscope analysis on Maniraptoriformes teeth from the Upper Cretaceous of Southeastern Brazil. JVP 21(3) 33A.

unnamed Troodontidae (Estes and Sanchiz, 1982)
Late Hauterivian-Early Barremian, Early Cretaceous
Castellar Formation, Spain
Material- teeth
Comments- These were referred to Coelosauridae by Estes and Sanchiz (1982).
Reference- Estes and Sanchiz, 1982. Early Cretaceous lower vertebrates from Galve (Teruel), Spain. Journal of Vertebrate Palaeontology. 2(1), 9-20.

unnamed Troodontidae (Antunes and Sigogneau-Russell, 1992)
Maastrichtian, Late Cretaceous
Unnamed unit, Distrito do Coimbra, Portugal
Material- (AV 7) fragmentary tooth
(TV 43) fragmentary tooth
(TV 52) fragmentary tooth
Reference- Antunes and Sigogneau-Russell, 1992. La Faune de Petits Dinosaures du Cretace Terminal Portugais. Comun. Serv. Geol. Portugal. 78(1), 49-62.

undescribed possible troodontid (Xu and Norell, 2006)
Early Aptian, Early Cretaceous
Dawangzhangzi Beds of Yixian Formation, Liaoning, China
Material- specimen including integument
Reference- Xu and Norell, 2006. Non-avian dinosaur fossils from the Lower Cretaceous Jehol Group of western Liaoning, China. Geological Journal. 41(3-4), 419-437.

unnamed possible troodontid (Mathur and Srivastava, 1987)
Maastrichtian, Late Cretaceous
Lameta Formation, India
Material- (GSI 19996) tooth
Comments- This was listed by Mathur and Srivastava (1987) as (?) Megalosaurus type E.
Reference- Mathur and Srivastava, 1987. Dinosaur teeth from Lameta Group (Upper Cretaceous) of Kheda District, Gujarat. Journal of the Geological Society of India. 29, 554-566.

Mei Xu and Norell, 2004
M. long Xu and Norell, 2004
Late Valanginian-Hauterivian, Early Cretaceous
Lujiatun Beds of Yixian Formation, Liaoning, China
Holotype- (IVPP V12733) (530 mm; subadult) incomplete skull (53 mm), sclerotic plates, incomplete mandible (56 mm), ten cervical vertebrae (67 mm), dorsal vertebrae (92 mm), dorsal ribs, gastralia, sacrum (30 mm), caudal vertebrae (257 mm), chevrons, scapulae (45 mm), coracoids, furcula, sternal rib fragments(?), humeri (42 mm), radii (39 mm), ulnae, (manus 67 mm) metacarpal I, phalanx I-1, manual ungual I, metacarpal II, phalanx II-1, phalanx II-2, manual ungual II, phalanx III-2, phalanx III-3, manual ungual III, ilia, pubes, ischium, femora (81 mm), tibiae (106 mm), fibula, astragali, distal tarsals, metatarsal I, phalanx I-1, pedal ungual I, metatarsal II, phalanx II-1, phalanx II-2, pedal ungual II, metatarsal III (58 mm), phalanx III-1, phalanx III-2, phalanx III-3, pedal ungual III, metatarsal IV, phalanx IV-1, phalanx IV-2, phalanx IV-3, phalanx IV-4, pedal ungual IV, metatarsal V
Diagnosis- (modified from from Xu and Norell, 2004) extremely large nares extending posteriorly over one half of the maxillary tooth row; closely packed middle maxillary teeth; maxillary tooth row extending posteriorly to the level of the preorbital bar; lateral process on distal tarsal IV; most proximal end of the pubic shaft is significantly compressed anteroposteriorly, and extends laterally just ventral to the articulation with the ilium.
Comments- Though assigned to Troodontidae bu Xu and Norell (2004), this is mostly based on the small, closely packed anterior dentary teeth and robust fourth metatarsal. Other characters used by them are also found in basal birds and/or basal dromaeosaurs, so may actually diagnose Paraves and/or Deinonychosauria and be reversed in other clades. For instance- birds besides Archaeopteryx have dorsoventrally flattened internarial bars; birds and Sinornithosaurus lack squamosal - quadratojugal contact; Sinornithosaurus and Buitreraptor have lateral dentary grooves; Graciliraptor has dorsally grooved distal caudals; Archaeopteryx, Rahonavis and Buitreraptor have short dorsal transverse processes.
Reference- Xu and Norell, 2004. A new troodontid dinosaur from China with avian-like sleeping posture. Nature. 431, 838-841.

undescribed troodontid (Hwang, Norell, Ji and Gao, 2004)
Late Valanginian-Hauterivian, Early Cretaceous
Lujiatun Beds of Yixian Formation, Liaoning, China
Material- (CAGS-IG01-004) incomplete skeleton including skull
Comments- This taxon shows small teeth with constricted bases and carinae lacking serrations, an apparently absent postorbital, and no quadratojugal-squamosal contact. It may be another specimen of Mei, and is said to be very similar to IGM 100/1323.
Reference- Hwang, Norell, Ji and Gao, 2004. A new troodontid from the lower Yixian Formation of China and its affinities to Mongolian troodontids. Journal of Vertebrate Paleontology. 24(3), 73A–74A.

undescribed troodontid (Hwang, Norell, Ji and Gao, 2004)
Late Campanian, Late Cretaceous
Djadokhta Formation, Mongolia
Material- (IGM 100/1005) skull, mandible, sacrum, twelve caudal vertebrae, distal radius, distal ulna, caprus, metacarpal I, distal phalanx I-1, manual ungual I, metacarpal II, phalanx II-1, phalanx II-2, manual ungual II, metacarpal III, phalanx III-1, phalanx III-2, phalanx III-3, manual ungual III, ilia, femora, tibiae, fibula, metatarsus, pedal ungual II, phalanx III-1, phalanx III-2, phalanx III-3, phalanx IV-1, phalanx IV-2
Late Campanian, Late Cretaceous
Djadokhta equivalent, Inner Mongolia, China
?(IVPP V10597) (.68 m; 1.1 kg; juvenile) femur (86.5 mm), nearly complete tibia (~105 mm), nearly complete fibula, astragalus, metatarsal I (4 mm), proximal phalanx I-1, metatarsal II (94 mm), phalanx II-1 (10.5 mm), phalanx II-2 (8.4 mm), proximal pedal ungual II, metatarsal III (107 mm), phalanx III-1 (14.5 mm), phalanx III-2 (12 mm), proximal phalanx III-3, metatarsal IV (105 mm), phalanx IV-1 (11 mm), phalanx IV-2 (10.5 mm), phalanx IV-3 (9 mm), phalanx IV-4 (9 mm), pedal ungual IV (8 mm), metatarsal V (21.5 mm) (Currie and Peng, 1993)
Comments- This specimen was collected from Ukhaa Tolgod in 1997. In the Fighting Dinosaurs: New Discoveries from Mongolia exhibit at the AMNH in 2000, it was displayed with troodontid postcrania. It is mislabeled on the AMNH website as the Shuvuuia holotype, though it differs in many respects from that taxon. Its braincase was analyzed by Franzosa (2004) as the Zos Canyon troodontid. Hwang et al. (2004) refer to a second Ukhaa Tolgod basal troodontid skull (in addition to IGM 100/1323), which based on their description I infer to be this specimen.
Currie and Peng (1993) described a hindlimb as a possible juvenile Saurornithoides mongoliensis, but Norell et al. believed this specimen to be merely Troodontidae indet., as they stated hindlimb elements were undiagnostic in Saurornithoides and Zanabazar. Yet the extremely slender elements are similar to a basal undescribed troodontid from the same stratigraphic level, while the short flexor lip on metatarsal III is more primitive than Saurornithoides. It is tentatively referred to that unnamed species here.
References- Currie and Peng, 1993. A juvenile specimen of Saurornithoides mongoliensis from the Upper Cretaceous of northern China. Canadian Journal of Earth Sciences. 30, 2224-2230.
Currie and Dong, 2001. New information on Cretaceous troodontids (Dinosauria, Theropoda) from the People's Republic of China. Canadian Journal of Earth Sciences. 38, 1753-1766.
http://paleo.amnh.org/gobi/gobi.swf
Franzosa, 2004. Evolution of the Brain in Theropoda (Dinosauria). PhD Thesis. The University of Texas at Austin. 357 pp.
Hwang, Norell, Ji and Gao, 2004. A new troodontid from the lower Yixian Formation of China and its affinities to Mongolian troodontids. Journal of Vertebrate Paleontology. 24(3), 73A–74A.
Norell and Hwang, 2004. A troodontid dinosaur from Ukhaa Tolgod (Late Cretaceous Mongolia). American Museum Novitates. 3446, 9 pp.
Norell, Makovicky, Bever, Balanoff, Clark, Barsbold and Rowe, 2009. A review of the Mongolian Cretaceous dinosaur Saurornithoides (Troodontidae: Theropoda). American Museum Novitates. 3654, 63 pp.

undescribed troodontid (Hwang, Norell, Ji and Gao, 2004)
Late Campanian, Late Cretaceous
Djadokhta Formation, Mongolia
Material- (IGM 100/1129) specimen including femur (84 mm)
(IGM 100/1323) specimen including skull and femur (80 mm)
Comments- This taxon is supposedly very similar to CAGS-IG01-004 in having teeth of the same number and morphology, and a modified diapsid configuration.
References- Hwang, Norell, Ji and Gao, 2004. A new troodontid from the lower Yixian Formation of China and its affinities to Mongolian troodontids. Journal of Vertebrate Paleontology. 24(3), 73A–74A.
Erickson, Rauhut, Zhou, Turner, Inouye, Hu and Norell, 2009. Was dinosaurian physiology inherited by birds? Reconciling slow growth in Archaeopteryx. PLoS ONE. 4(10), e7390. doi:10.1371/journal.pone.0007390

Sinovenator Xu, Norell, Wang, Makovicky and Wu, 2002
S. changii Xu, Norell, Wang, Makovicky and Wu, 2002
Late Valanginian-Hauterivian, Early Cretaceous
Lujiatun Beds of Yixian Formation, Liaoning, China
Holotype- (IVPP V12615) partial skull, incomplete dentary, four cervical vertebrae, twelve dorsal vertebrae, two partial dorsal ribs, sacrum, four caudal vertebrae, scapula (49 mm), coracoid, distal humerus, ulna (54 mm), metacarpal, manual ungual, ilium, pubis, ischium, femora (117.5 mm), tibiae (153.5 mm), metatarsal II (74 mm), phalanx II-2, pedal ungual II, metatarsal III (85 mm), metatarsal IV (80 mm)
Paratype- (IVPP V12583) mandible, cervical vertebrae, dorsal vertebrae, dorsal ribs, proximal humerus, manual phalanges, manual unguals, pubis, ischium, femora, tibiae, partial fibula, metatarsal II, phalanx II-1, phalanx II-2, pedal ungual II, metatarsal III, phalanx III-1, phalanx III-2, metatarsal IV, phalanx IV-1, phalanx IV-2
Referred- (IVPP V14322) fragmentary skull, fragmentary skeleton (Manabe, 2005)
(IVPP coll.) femur (206 mm), tibia (147 mm), metatarsal II, phalanx II-1, phalanx II-2, metatarsal III (92 mm), phalanx III-1, phalanx III-2, phalanx III-3 metatarsal IV, phalanx IV-1, phalanx IV-2, phalanx IV-3, phalanx IV-4, pedal ungual IV (White, 2009)
? skull, cervical vertebrae, dorsal ribs, sacral vertebrae, caudal vertebrae, scapula, humerus, radius, ulna, manus, ilia, femur, tibiae, fibula, pes (Fossil Mall online)
Diagnosis- (after Xu et al., 2002) straight and vertical anterior margin of antorbital fenestra; frontal with a vertical lamina bordering the lacrimal; surangular T-shaped in cross-section; prominent lateral cnemial crest continuous with the fibular crest.
Comments- Creisler (DML 2002) noted Sinovenator changii was named after a woman, so suggested it be emended to S. changiae, which is followed on several websites. However, the Fourth Edition of the ICZN no longer requires emendations based on this reasoning (Article 31.1.3). If Sinovenator "changiae" is ever published, ICZN Article 32.2.3 states it will become an available name with its own authorship, though an objective junior synonym of S. changii.
Senter (2007) mentioned an undescribed specimen whose photo is available on www.dinosaur.net.cn, but this is possibly the paratype, as the other Lujiatun specimens at that show are type specimens (Incisivosaurus, Graciliraptor) and the paratype was said to be articulated by Xu et al.. Furthermore, it shows the proximodorsal ischial process and right tibiotarsus and metatarsus very clearly, as indicated for the paratype. Another possibility is that it represents IVPP V14322.
White (2009) describes and illustrates the pes of an unregistered specimen at the IVPP as Sinovenator sp.
An undescribed basically complete specimen is referred to Sinovenator on the Fossil Mall website, but may be at least partially faked due to its apparent lumbar region and non-maniraptoran forelimb position.
Senter et al. (2004) corrected Xu et al.'s description of several characters, finding the teeth to be unserrated, the antorbital fossa to lack a prominent rim, the anterior and posterior dentary teeth to be subequal in size and density, and the fourth metatarsal to be subequal in diameter to the second. Senter (2007) later corrected his account of dentary tooth density, agreeing with Xu et al. that the anterior teeth were more densely packed.
References- Xu, Norell, Wang, Makovicky and Wu, 2002. A basal troodontid from the Early Cretaceous of China. Nature. 415, 780-784.
http://dml.cmnh.org/2002Feb/msg00579.html
http://www.dinosaur.net.cn/_Kyohaku2004/show_fly.htm
Senter, Barsbold, Britt and Burnham, 2004. Systematics and evolution of Dromaeosauridae. Bulletin of Gunma Natural History Museum. 8, 1-20.
Manabe, 2005, The Dinosaur expo 2005. 151pp.
Senter, 2007. A new look at the phylogeny of Coelurosauria. Journal of Systematic Palaeontology.
http://www.fossilmall.com/Science/Sites/China/Sinovenator/Sinovenator.jpg
White, 2009. The subarctometatarsus: intermediate metatarsus architecture demonstrating the evolution of the arctometatarsus and advanced agility in theropod dinosaurs. Alcheringa. 33(1), 1-21.

Hulsanpes Osmolska, 1982
H. perlei Osmolska, 1982
Middle Campanian, Late Cretaceous
Baron Goyot Formation, Mongolia
Holotype- (ZPAL MgD-I/173) (~360 mm; juvenile) (?)otico-occipital fragment, metatarsal II (~34 mm), phalanx II-1 (~6.5 mm), proximal phalanx II-2, metatarsal III (~39 mm), proximal phalanx III-1, metatarsal IV (~36 mm)
Diagnosis- metatarsal III expanded proximally; metatarsus excavated on plantar surface.
Comments- This specimen was discovered in 1970 and described twelve years later. Using Mei as a guide, we can estimate Hulsanpes was about 360 mm long, but it was juvenile based on the rough bone texture and the badly abraded articular joints.
The metatarsus "lacks even incipient fusion" (contra Holtz), and is non-arctometatarsalian to the point that metatarsal III expands proximally. It is fairly slender and metatarsal III is slightly more robust than the others. Distally, metatarsal III flattens and widens to partially overlap metatarsal II. The metatarsus is concave posteriorly, with metatarsal III inset compared to the others. The distal end of metatarsal III is shallowly grooved with a symmetrical ginglymus. The distal end of metatarsal IV is transversely flattened and diverges from metatarsal III. The articular surface is narrow and undivided, with a groove posterior to it.
Pedal phalanx I-1 is rather similar to Deinonychus. The proximal end has an elongate articular surface divided asymmetrically by a ridge, showing that the articulation of metatarsal II was ginglymoid. The distal end is divided asymmetrically by a long groove that extends more dorsally than ventrally. The medial condyle is a bit wider and lower. The ligamental fossae are deep and the lateral one is more centrally placed.
Although the second digit could hyperextend, the proximoventral heel of phalanx II-2 was not well-developed.
Relationships- The proximoventral heel on phalanx II-2 and hyperextendable second digit show Hulsanpes is non-ornithurine (sensu Gauthier) eumaniraptoran. When entered into Senter's (2007) matrix, Hulsanpes emerges as a troodontid based on the distally narrowing metatarsus. Hulsanpes resembles Sinovenator more than other troodontids in having a ginglymoid metatarsal II, but resembles most eumaniraptorans besides Sinovenator and some avialans in having a ginglymod metatarsal III. It shares anteroposteriorly deep metatarsals with troodontids more derived than Sinovenator. It is more basal than Sinovenator, Mei and other troodontids in having a broader metatarsus, and it is more basal than Mei and other troodontids except Sinovenator in having metatarsals II and IV subequal in thickness. The basic morphology of the metatarsus is extremely similar to Sinovenator, including the short metatarsal II with reduced distal condyle and large somewhat divergent condyle of metatarsal IV.
Osmolska allied this species with dromaeosaurids based on the ginglymoid second and third metatarsals and subequally developed metatarsals II and IV, but noted it resembled troodontids in the narrow metatarsus and weakly developed second pedal digit. She dismissed avian origins based on the lack of fusion. Senter et al. (2004) is the only published analysis to include Hulsanpes, which emerged as a dromaeosaurid because they miscoded the ginglymoid metatarsal II as absent in Sinovenator. Chiappe and Norell (Norell pers. comm. to Currie, 2001) think Hulsanpes is not a dromaeosaurid, but from "another more speciose branch of the Maniraptora". Holtz (DML, 1995) wrote that the metatarsals and distal tarsals are fused at least distally in this species, like birds. He also cryptically said "future work may show why this is no surprise....". Then in May of 1997 (DML), Holtz said that Hulsanpes is almost certainly not a dromaeosaurid. The description specifically states that the metatarsus is unfused however, contradicting Holtz's statement (but not his conclusion). However, the only obviously birdlike character is the proximally expanded metatarsal III also seen in Yandangornis and basal avebrevicaudans. Though not included in Senter's character list, placing Hulsanpes in Avialae results in trees at least three steps longer. Thus the expanded third metatarsal would not be enough to remove Hulsanpes from Troodontidae. An additional test was carried out by adding Hulsanpes to a matrix of published Mesozoic birds (using the characters of Clarke and Chiappe, along with many more taxa). Though the excavated plantar metatarsus surface is similar to some pygostylians, Hulsanpes still falls out by deinonychosaurs at the base of the tree.
References- Osmolska, 1982. Hulsanpes perlei n. g. n. sp. (Deinonychosauria, Saurischia, Dinosauria) from the Upper Cretaceous Barun Goyot Formation of Mongolia. Neues Jahrbuch fur Geologie und Palaeontologie, Monatshefte. 1982(7), 440-448.
http://dml.cmnh.org/1995Sep/msg00030.html
http://dml.cmnh.org/1997May/msg00576.html
Currie, 2001. Theropod dinosaurs from the Cretaceous of Mongolia. in Benton, Shishkin, Unwin and Kurochkin, eds. The Age of Dinosaurs in Russia and Mongolia. 434-455.
Senter, Barsbold, Britt and Burnham, 2004. Systematics and evolution of Dromaeosauridae. Bulletin of Gunma Natural History Museum. 8, 1-20.
Senter, 2007. A new look at the phylogeny of Coelurosauria. Journal of Systematic Palaeontology.

Jinfengopteryx Ji, Ji, Lu, You, Chen, Liu and Liu, 2005
J. elegans Ji, Ji, Lu, You, Chen, Liu and Liu, 2005
Early Aptian, Early Cretaceous
Qiaotou Member of the Huajiying Formation, Hebei, China
Holotype- (CAGS-IG-04-0801) (548 mm) skull (~68 mm), sclerotic plates, mandible, hyoids, twelve cervical vertebrae, cervical ribs, eleven dorsal vertebrae, dorsal ribs, gastralia, twenty-four caudal vertebrae (273 mm), chevrons, scapulae (47.09 mm), coracoid, furculae, humeri (49.22 mm), radii (42.44 mm), ulnae (43.31 mm), radiale, semilunate carpal, metacarpal I (8.77 mm), phalanx I-1 (18.83 mm), manual ungual I (17.75 mm), metacarpal II (21.37 mm), phalanx II-1 (15.26 mm), phalanx II-2 (21.07 mm), manual ungual II (17.32 mm), metacarpal III, phalanx III-1+III-2 (10 mm), phalanx III-3 (12.95 mm), manual ungual III, partial ilium, pubes, partial ischium, femora (70.32 mm), tibiae (100.5 mm), fibula (98.75 mm), proximal tarsus, metatarsus, pedal digit II, pedal digit III, pedal digit IV, feathers, gastroliths/eggs/seeds
Diagnosis- more than ten cervical vertebrae; less than twelve dorsal vertebrae; scapula expanded distally more than twice minimal shaft width; manual phalanges III-1 and III-2 fused.
Comments- Jin et al. (2008) reassign Jinfengopteryx's horizon to the Qiaotou Member of the Huajiying Formation, as opposed to the Qiaotau Formation which was stated in Ji et al. (2005).
Though Ji et al. (2005) assign it to the Archaeopterygidae, Jinfengopteryx is remarkably unbirdlike in several ways. The naris is small and anteriorly positioned, with a short dorsal premaxillary process above it. The snout is more rounded than avialans. The maxillary and promaxillary fenestrae take up a larger percentage of the antorbital fossa length. There are a large amount of maxillary teeth. The scapula is distally expanded (like scansoriopterygids). The first manual digit is comparatively robust. The first metacarpal is longer than most paravians.
There are a few birdlike characters, but they are all too derived for an archaeopterygid- twelve cervicals, eleven dorsals, fused manual phalanges III-1 and III-2.
After entering it into my matrix, Jinfengopteryx emerges as a basal troodontid (Mortimer, DML 2005). Characters that may support this include the robust lacrimal (compare to Mei), smaller and closely packed anterior teeth, apically expanded dorsal neural spines (like Sinovenator and Mei), short pedal digit II, and possibly the absence of ossified uncinate processes and sterna (if their absence in Sinornithoides is real). This would also fit well with the short forelimbs and slender furcula. The snout resembles Sinovenator fairly closely. Xu and Norell (2006) stated Jinfengopteryx was a possible troodontid based on "general body plan" and several undisclosed dental features.
Ji et al. assign it to the Archaeopterygidae based on the triangular skull (as in Sinovenator and Mei), cervical ribs longer than their respective centra, extensive contact between the semilunate and metacarpal I (as in IGM 100/44 and Sinornithoides), and two characters which require comment. One is "conical tooth with D shaped in cross-section", as contrasted with "curved tips with sharp anterior and posterior cutting edges". This is scored as derived in Archaeopteryx and Jinfengopteryx and basal in other taxa. However, Archaeopteryx has recurved teeth with carinae, and Jinfengopteryx's teeth are illustrated as recurved. The other is a second caudal centrum less than half the length of the first. But this ratio in Archaeopteryx is 110-140%, a far cry from <50%. The condition in Jinfengopteryx seems to be caused by Ji et al. treating the first two caudals as one vertebra, as the illustration suggests two chevrons are associated with it.
There are a couple other characters scored in Ji et al.'s matrix which may may have led Jinfengopteryx to group with birds. The coronoid is scored as absent, despite the poor preservation in this area and its presence in such derived taxa as Ichthyornis. Similarly, the external mandibular fenestra is scored as absent, despite the covered posterior surangular area and medial view of the mandible.
The last question is how are Sinovenator and Jinfengopteryx coded differently by Ji et al., allowing them to be placed apart. Ji et al. incorrectly code Sinovenator as having dental serrations (Senter et al., 2004), enlarged anterior dorsal hypapophyses, more than twenty-seven caudals (actually unknown), proximal caudal transverse processes subequal to central width and a dorsally arched scapular blade. Sinovenator has an unfused scapulocoracoid unlike Jinfengopteryx, but may be immature judging by the unfused braincase and sacral elements. Sinovenator is coded as having a pointed acromion, though it is broken, while Jinfengopteryx's is coded as blunt, though it appears pointed in the illustration. Sinovenator is coded as having a proximally domed humeral head, unlike Jinfengopteryx. Sinovenator is also supposed to differ in the orientation and size of its deltopectoral crest. I have yet to study humeral morphology in detail, so cannot comment on these three characters. Sinovenator is coded as having short cervical ribs, but this was coded as unknown by Xu et al. (2002). The other two 'differences' relate to the last problematic supposed archaeopterygid synapomorphies described above, so are absent in both Sinovenator and Jinfengopteryx. So their separation in Ji et al.'s tree is largely due to miscodings.
Finally, a couple notes about Ji et al.'s identifications. The labeled "pterygoid" looks to be a parasphenoid rostrum, the "squamosal" part of the parietal.
References- Ji, Ji, Lu, You, Chen, Liu and Liu, 2005. First avialan bird from China (Jinfengopteryx elegans gen. et sp. nov.). Geological Bulletin of China 24(3): 197-205.
http://dml.cmnh.org/2005Mar/msg00372.html
Xu and Norell, 2006. Non-avian dinosaur fossils from the Lower Cretaceous Jehol Group of western Liaoning, China. Geological Journal. 41(3-4), 419-437.
Ji and Ji, 2007. Jinfengopteryx compared to Archaeopteryx, with comments on the mosaic evolution of long-tailed avialan birds. Acta Geologica Sinica (English Edition). 81(3), 337-343.
Jin, Zhang, Li, Zhang, Li and Zhou, 2008. On the horizon of Protopteryx and the early vertebrate fossil assemblages of the Jehol Biota. Chinese Science Bulletin. 53(18), 2820-2827.

unnamed clade
Diagnosis- distal carina of some teeth serrated.

unnamed troodontid (Barsbold, Osmolska and Kurzanov, 1987)
Aptian-Albian, Early Cretaceous
Barunbayaskaya (or Huhteeg?) Svita, Mongolia
Material- (IGM 100/44) quadrate, baincase fragment, dentary fragment, posterior mandible, four teeth (2.5-3 mm), five partial cervical neural arches (22-25 mm), semilunate carpal, metacarpal I (15 mm), phalanx I-1 (36 mm), manual ungual I (18 mm), metacarpal II (40 mm), phalanx II-1 (26 mm), incomplete phalanx II-2 (24 mm), manual ungual II, metacarpal III (~37 mm), manual ungual III, distal femur, metatarsal I (13 mm), phalanx I-1 (13 mm), distal metatarsal II, phalanx II-1 (25 mm), phalanx II-2 (17 mm), pedal ungual II (~20 mm), distal metatarsal III (~108 mm), phalanx III-1 (29 mm), phalanx III-2 (17 mm), phalanx III-3 (~12 mm), distal metatarsal IV, phalanx IV-1 (19 mm), phalanx IV-2 (~13 mm), pedal ungual IV fragment
Reference- Barsbold, Osmolska and Kurzanov, 1987. On a new troodontid (Dinosauria, Theropoda) from the Early Cretaceous of Mongolia. Acta Palaeontologica Polonica. 32(1-2), 121-132.

Sinusonasus Xu and Wang, 2004
S. magnodens Xu and Wang, 2004
Late Valanginian-Hauterivian, Early Cretaceous
Lujiatun Beds of Yixian Formation, Liaoning, China
Holotype- (IVPP V 11527) (adult) incomplete skull (~109 mm), incomplete mandible, several dorsal ribs, gastralia, sacrum, twenty-seven caudal vertebrae (537 mm), chevrons, pubis (113 mm), ischia (61 mm), femur (141 mm), tibiae (186 mm), fibula (167 mm), metatarsal I (22.7, 19.9 mm), phalanx I-1 (10.2, 12.1 mm), pedal ungual I (15.7, 15.7 mm), metatarsal II (93.5 mm), phalanx II-1 (24.2, 21.2 mm) phalanx II-2 (17.6, 20.6 mm), pedal ungual II (31.1 mm), metatarsal III (~108 mm), phalanx III-1 (28.5 mm), phalanx III-2 (19.1 mm), phalanx III-3 (19.4 mm), pedal ungual III (13.6 mm), metatarsal IV (106.6 mm), phalanx IV-1, phalanx IV-2 (13.7 mm), phalanx IV-3 (14.7 mm), metatarsal V
Diagnosis- (after Xu and Wang, 2004) interantorbital canal absent; nasal sinusoid in lateral view; middle maxillary teeth relatively large; distal chevrons elongated to contact each other anteroposteriorly; femoral neck long.
Comments- This genus was consistantly mispelled Sinucerasaurus by Xu and Norell (2006), though the latter was written over a year after the publication of Sinusonasus.
Reference- Xu and Wang, 2004. A New Troodontid (Theropoda: Troodontidae) from the Lower Cretaceous Yixian Formation of Western Liaoning, China. Acta Geologica Sinica. 78(1), 22-26.
Xu and Norell, 2006. Non-avian dinosaur fossils from the Lower Cretaceous Jehol Group of western Liaoning, China. Geological Journal. 41(3-4), 419-437.

unnamed clade
Diagnosis- mesial carinae of some teeth serrated.

unnamed troodontid (Dong, 1997)
Barremian-Albian, Early Cretaceous
Xinminbao Group, Gansu, China
Material- (IVPP V11119) two teeth, two caudal vertebrae, partial tibia, distal tarsal, incomplete metatarsal II, phalanx II-1 (17 mm), phalanx II-2 (13 mm), pedal ungual II (9 mm), distal metatarsal III, phalanx III-1, partial metatarsal IV, phalanx IV-1
Comments- Dong (1997) referred this to Sinornithoides sp. nov. based on undescribed distal tarsal similarities, subequal size, and the plesiomorphically limited proximal extent of the distal articular surface on metatarsal III. However, he notes the less robust metatarsal IV differs. This suggests the specimen was outside the Sinornithoides+Troodon clade and should not be referred to the former genus. The teeth are said to have serrations (though smaller than derived troodontids), suggesting the taxon is closer to Troodon than Sinovenator or Mei.
Reference- Dong, 1997. On small theropods from Mazongshan Area, Gansu Province, China. Pp. 13-18. in Dong (ed). Sino-Japanese Silk Road Dinosaur Expedition. China Ocean Press, Beijing. 114 p.

unnamed troodontid (Dong, 1997)
Barremian-Albian, Early Cretaceous
Xinminbao Group, Gansu, China
Material- (IVPP V11122-2) tooth
Comments- This short recurved tooth with a basal constriction was reported to have mesial and distal serrations. It was referred to Troodontidae. It may belong to the same taxon as IVPP V11119.
Reference- Dong, 1997. On small theropods from Mazongshan Area, Gansu Province, China. Pp. 13-18. in Dong (ed). Sino-Japanese Silk Road Dinosaur Expedition. China Ocean Press, Beijing. 114 p.

unnamed possible troodontid (Grigorescu, Hartemberger, Radulescu, Samson and Sudre, 1985)
Late Maastrichtian, Late Cretaceous
Sinpetru Beds, Romania
Material- (FGGUB R.1318) tooth (12.5 mm)
(FGGUB R.1319) tooth (11 mm)
(FGGUB R.1320) tooth (5.3 mm)
(MAFI v.12685) tooth (11.2 mm), tooth (8 mm)
Comments- These teeth are most similar to Koparion in having constricted roots, blood pits and enlarged serrations (~5/mm) which are present on both carinae, yet not enlarged to the extent seen in Saurornithoides and Troodon, nor apically hooked. They differ in being much larger and less recurved, with flat distal serrations.
References- Grigorescu, Hartemberger, Radulescu, Samson and Sudre, 1985. Decouverte de Mammiferes et Dinosaures dans le Cretace superieur de Pui (Roumanie). Compte rendu hebdomadaire des seances de l’Academie des Sciences Paris. 301, 2(19), 1365-1368.
Csiki and Grigorescu, 1998. Small Theropods from the Late Cretaceous of the Hateg Basin (Western Romania) - an unexpected diversity at the top of the food chain. Oryctos. 1, 87-104.

Koparion Chure, 1994
K. douglassi Chure, 1994
Late Kimmeridgian, Late Jurassic
Brushy Basin Member of the Morrison Formation, Utah, US
Holotype- (DINO 3353) maxillary tooth (2 mm)
Diagnosis- differs from Sinusonasus, Sinornithoides and "Saurornithoides" asiamericanus in having mesial serrations on lateral teeth; differs from Sinornithoides, "Saurornithoides" asiamericanus, Saurornithoides and Troodon in having comparatively smaller distal serrations; differs from "Saurornithoides" asiamericanus, Saurornithoides and Troodon in having distal serrations which are not hooked apically.
Comments- Although Chure no longer thinks Koparion is a troodontid (pers. comm. to Harris, 1997; in Naish, DML 1997), there are no other suggested phylogenetic placements which are supported by the evidence. Rauhut (2000) suggested it might be a compsognathid, but Compsognathus differs in lacking mesial serrations. Compsognathus-like teeth from Guimarota described by Zinke (1998) do have mesial serrations, but Koparion differs in having no blood pits, and less serrations per mm on both carinae (8 and 7 on mesial and distal vs. 10-17 and 10-15 in cf. Compsognathus) despite similar crown size. These are more similar to derived troodontids. The only other theropods with constricted tooth bases and serrated teeth are Richardoestesia-like taxa and therizinosaurs. Richardoestesia and related taxa differ in having highly elongate teeth with extremely numerous serrations with no blood pits. Therizinosauroids have much larger serrations (~3/mm in Beipiaosaurus and Alxasaurus), while Falcarius' serration size is comparable. However, maxillary teeth of Falcarius have convex distal edges with serrations smaller in comparison to tooth size. Smaller posterior dentary teeth are schematically illustrated as being more recurved, so may be more comparable to Koparion. Therizinosaurs also lack blood pits. Koparion differs from Sinusonasus in having mesial serrations, though they are similar in having small distal serrations without apically hooked tips. It differs from Sinornithoides and "Saurornithoides" asiamericanus in having comparatively smaller distal serrations (Currie and Dong, 2001), and having mesial serrations on non-premaxillary teeth. It further differs from "Saurornithoides" americanus in having distal serrations whose tips are not hooked.
References- Chure and Britt, 1993. New data on theropod dinosaurs from the Late Jurassic Morrison Fm. (MF). Journal of Vertebrate Paleontology. 13(3), 30A.
Chure, 1994. Koparion douglassi, a new dinosaur from the Morrison Formation (Upper Jurassic) of Dinosaur National Monument; The oldest troodontid (Theropoda: Maniraptora). Brigham Young University Geological Studies. 40, 11-15.
http://dml.cmnh.org/1997Jan/msg00325.html
Zinke, 1998. Small theropod teeth from the Upper Jurassic coal mine of Guimarota (Portugal). Palaontologische Zeitschrift. 72(1/2) 179-189.
Rauhut, 2000. The interrelationships and evolution of basal theropods (Dinosauria, Saurischia). Ph.D. dissertation, University of Bristol, Bristol. 583 pp.
Currie and Dong, 2001. New information on Cretaceous troodontids (Dinosauria, Theropoda) from the People’s Republic of China. Canadian Journal of Earth Sciences. 38, 1753-1766.

Byronosaurus Norell, Makovicky and Clark, 2000
= "Byranjaffia" Novacek, 2002
B. jaffei Norell, Makovicky and Clark, 2000
Late Campanian, Late Cretaceous
Djadokhta Formation, Mongolia
Holotype- (IGM 100/983) partial skull, incomplete mandibles, posterior axis, incomplete third cervical vertebra, anterior fourth cervical vertebra, fourth cervical rib, two anterior dorsal centra, posterior dorsal vertebrae, dorsal rib fragment, possible sacral centrum, four distal caudal fragments, distal femur (~150 mm), proximal tibia, proximal fibula, limb bone fragments, distal metatarsal II, phalanx II-2, distal phalanx III-2, proximal phalanx III-3
Paratype- (IGM 100/984) premaxillae, anterior maxillae, maxillary fragment, lacrimals, posterior nasals, vomer fragment
Referred- (IGM 100/972) (juvenile) partial premaxillae, maxillae, nasals, lacrimals, incomplete jugals, anterior frontal, palatal elements, incomplete mandible (Norell, Clark, Demberelyin, Barsbold, Chiappe, Davidson, McKenna, Perle and Novacek, 1994)
?(IGM 100/974) (juvenile) incomplete skull, posterior mandible (Norell, Clark, Demberelyin, Barsbold, Chiappe, Davidson, McKenna, Perle and Novacek, 1994)
(IGM 100/1003) (adult) tooth
....(juvenile) skeleton including cervical vertebrae, dorsal ribs, incomplete femora, tibiae, fibula, metatarsi, pedal phalanges, thirteen eggs, nest (Clark et al., 2002)
Diagnosis- (after Makovicky et al., 2003) teeth lacking serrations; interfenestral bar is not recessed from the plane of the maxilla; shallow groove along the buccal margin of the maxilla.
Comments- The holotype was discovered in 1993 and illustrated as an undescribed troodontid in Novacek et al. (1994). Its unassociated remains were mixed with those of ornithomimid specimen IGM 100/987. The paratype was found later in 1996. Novacek (2002) used the name "Byranjaffia" in his book for Byronosaurus. The former is either a misspelling or an unpublished name previously intended for the genus.
Two juvenile skulls were found associated with a Citipati nest (Norell et al., 1994). They were identified by Norell et al. as Velociraptor, based on their long premaxillae (on IGM 100/974 at least). However, Norell and Makovicky (1999) state that Norell et al. (in press) will show they are actually troodontids (which later became Bever and Norell, 2009). This is supported by their anatomy, while their serrationless teeth suggest they may belong to the contemporaneous Byronosaurus. At least one additional undescribed troodontid with serrationless teeth is known from the Djadokhta Formation however (Hwang et al., 2004), making the situation less certain. In fact, my examination of available photographs suggests IGM 100/972 may resemble Byronosaurus more closely while 100/974 resembles the undescribed basal troodontid specimen IGM 100/1005. Bever and Norell (2009) confirm their assignment to Byronosaurus. Sues and Averianov (2007) mistakenly state IGM 100/974 was reidentified as an oviraptorid, and that the serrationless teeth were actually maxillary palatal bumps, but they were confusing it with embryonic Citipati specimen IGM 100/971.
Norton (DML, 2000) first noted this specimen was on display at the AMNH's Fighting Dinosaurs exhibit. A photo appears on the AMNH website. Clark et al. (2002) noted an undescribed nest with juveniles and an adult tooth as being the subject of an upcoming paper (Norell et al., in prep.). It may be the same specimen, and belong to Byronosaurus, as Grellet-Tinner and Makovicky (2006) code Byronosaurus eggshells.
References- Norell, Clark, Dashzeveg, Barsbold, Chiappe, Davidson, McKenna and Novacek, 1994. A theropod dinosaur embryo, and the affinities of the Flaming Cliffs dinosaur eggs. Science 266, 779-782.
Novacek, Norell, McKenna and Clark, 1994 Fossils of the Flaming Cliffs. Scientific American. 271(6), 60-69.
Norell and Makovicky, 1999. Important features of the dromaeosaurid skeleton II: information from newly collected specimens of Velociraptor mongoliensis. American Museum Novitates. 3282, 1-45.
Norell, Makovicky and Clark, 2000. A new troodontid theropod from Ukhaa Tolgod, Mongolia. Journal of Vertebrate Paleontology. 20(1), 7-11.
http://dml.cmnh.org/2000Jun/msg00082.html
Clark, Norell and Makovicky, 2002. Cladistic approaches to the relationships of birds to other theropod dinosaurs. in Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 31-64.
Novacek, 2002. Time Traveler: In search of dinosaurs and ancient mammals from Montana to Mongolia. Farrar, Strauss and Giroux, New York. 368 + xii pp.
Makovicky, Norell, Clark and Rowe, 2003. Osteology and relationships of Byronosaurus jaffei (Theropoda: Troodontidae). American Museum Novitates. 3402, 1-32.
Hwang, Norell, Ji and Gao, 2004. A new troodontid from the lower Yixian Formation of China and its affinities to Mongolian troodontids. Journal of Vertebrate Paleontology. 24(3), 73A–74A.
Grellet-Tinner and Makovicky, 2006. A possible egg of Deinonychus antirrhopus: Phylogenetic and biological implications. Canadian Journal of Earth Sciences. 43, 705-719.
Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.
http://www.amnh.org/exhibitions/fightingdinos/ex4.php
Bever and Norell, 2009. The perinate skull of Byronosaurus (Troodontidae) with observations on the cranial ontogeny of paravian theropods. American Museum Novitates. 3657, 51 pp.
Erickson, Rauhut, Zhou, Turner, Inouye, Hu and Norell, 2009. Was dinosaurian physiology inherited by birds? Reconciling slow growth in Archaeopteryx. PLoS ONE. 4(10), e7390. doi:10.1371/journal.pone.0007390

unnamed clade
Diagnosis- distal serrations hooked apically.

unnamed Troodontidae (Novikov, Lebedev and Alifanov, 1998)
Aptian-Albian, Early Cretaceous
Ilek (=Shestakovo) Formation, Russia
Material- (PM TGU 16/5-124) maxillary or posterior dentary tooth
(PM TGU coll.) caudal vertebra, metacarpal I
(lost) fragmentary skeleton including jaw element, teeth, tarsus (Alifanov et al., 1999)
References- Novikov, Lebedev and Alifanov, 1998. New Mesozoic vertebrate fossil sites of Russia. Third European Workshop on Vertebrate Paleontology, Maastricht, 6-9 May 1998, p. 58.
Alifanov, Efimov, Novikov and Morales, 1999. [A new psittacosaur complex of tetrapods from the Lower Cretaceous Shestakovo locality (southern Siberia).] Doklady Akademii Nauk. 369(4), 491–493. [Russian]
Alifanov, Efimov, Novikov and Morales, 1999. A new psittacosaurian complex of tetrapods from the Lower Cretaceous Shestakovo locality (Southern Siberia). Doklady Earth Sciences. 369A(9), 1228–1230.
Leshchinskiy, Voronkevich, Fayngertz, Maschenko, Lopatin and Averianov, 2001. Early Cretaceous vertebrate locality Shestakovo, Western Siberia, Russia: A refugium for Jurassic relicts? Journal of Vertebrate Paleontology. 21(3), 73A.
Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.

unnamed troodontid (Currie, Rigby and Sloan, 1990)
Late Campanian, Late Cretaceous
Dinosaur Park Formation of the Judith River Group, Alberta, Canada
Material- (RTMP 79.8.635) tooth (3.3 mm) (Currie, Rigby and Sloan, 1990)
(RTMP 85.30.1) tooth (Currie, Rigby and Sloan, 1990)
(RTMP 2000.19.1) tooth (5.5 mm) (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 2000.20.1) tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 2000.21.11) tooth (5.2 mm) (Sankey, Brinkman, Guenther and Currie, 2002)
Late Maastrichtian, Late Cretaceous
Lance Formation, Montana, Wyoming, US
(AMNH 8114) tooth (Estes, 1964)
?(AMNH 27117) eleven teeth (Estes, 1964; AMNH online)
Diagnosis- (after Sankey et al., 2002) tooth crowns flattened or concave on one side; enamel pitted on flat/concave side; two well-developed longitudinal ridges present on flat surface, one ridge extending from the apex denticle to near the base of the enamel and the second extending along the anterior carina; mesial serrations always absent; distal serrations rounded.
Comments- This tooth morphology was considered a pathological varient of Troodon formosus by Currie et al. (1990), who referred to it as "Paronychodon" (Troodon). Sankey et al. (2002) considered it a valid taxon though, based on its differing temporal and spatial distribution than Troodon formosus. Specifically, this taxon is restricted to the upper Dinosaur Park Formation within the Judith River Group, and has not been reported from the Prince Creek Formation where T. formosus is common. Sankey et al. also referred teeth described by Estes (1964) as cf. Saurornithoides sp. from the Lance Formation to this species, based on figured specimen AMNH 8114. Troodon bakkeri from that formation is not the same as this taxon, as it has pointed distal serrations like Troodon formosus. It's highly possible additional Late Cretaceous North American teeth currently identified as Troodon belong to this taxon.
References- Estes, 1964. Fossil vertebrates from the Late Cretaceous Lance Formation, eastern Wyoming. University of California Publications in Geological Sciences. 49, 1-180.
Currie, Rigby and Sloan, 1990. Theropod teeth from the Judith River Formation of southern Alberta, Canada. in Carpenter and Currie (eds.). Dinosaur Systematics: Perspectives and Approaches. Cambridge University Press, New York. pp. 107-125.
Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.

undescribed troodontid (Hartman, Lovelace and Wahl, 2005)
Late Kimmeridgian, Late Jurassic
Brushy Basin Member of the Morrison Formation, Wyoming, US
Material- (WDC DML0001; Lori) (~1.5 m; adult) incomplete skull, incomplete mandible, hyoid, four cervical vertebrae, cervical rib, dorsal vertebra, several partial dorsal ribs, twelve caudal vertebrae, four chevrons, partial scapula, partial coracoid, furcula, incomplete humerus, distal radius, distal ulna, radiale, semilunate carpal, metacarpal I, manual ungual I, metacarpal II, manual ungual II, metacarpal III, partial phalanx III-1, phalanx III-2, phalanx III-3, manual ungual III, ilial fragment, incomplete femur, tibia, fibula, proximal tarsus, distal tarsal, metatarsal II, metatarsal III, phalanx III-1, phalanx III-2, pedal ungual III, metatarsal IV, phalanx IV-1, phalanx IV-2, phalanx IV-3, phalanx IV-4, metatarsal V
Description- antorbital fossa with distinct rim; elongate posterior lacrimal process; pneumatic quadrate; dentary lateral nutrient foramina within deep groove; dentary interdental plates absent; base of teeth slightly constricted; distal caudal vertebrae with dorsal midline sulcus; anteriorly bifurcated chevrons; semilunate carpal; extremely reduced fibula; arctometatarsalian pes; metatarsal IV more robust than II.
Comments- This specimen was discovered in 2000 or 2001 and will be described soon. In Hartman et al.'s (2005) preliminary analysis, it claded with Sinornithoides.
Reference- Hartman, Lovelace and Wahl, 2005. Phylogenetic assessment of a maniraptoran from the Morrison Formation. Journal of Vertebrate Paleontology. 25(3), 67A.

unnamed Troodontidae (Averianov and Sues, 2007)
Early Cenomanian, Late Cretaceous
Khodzhakul Formation, Uzbekistan
Material- (ZIN PH 1885/16) anterior dentary tooth
(ZIN PH 1886/16) anterior dentary tooth
(ZIN PH 1888/16) maxillary tooth
(ZIN PH coll.) six teeth, postcrania
Comments- These are indistinguishable from and may belong to "Saurornithoides" asiamericanus.
Reference- Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.

"Saurornithoides" asiamericanus (Nessov, 1995) Olshevsky, 2000
= Pectinodon "asiamericanus" Nessov, 1985
= Saurornithoides "asiamericanus" (Nessov, 1985) Olshevsky, 1991
= Troodon asiamericanus Nessov, 1995
Early Cenomanian, Late Cretaceous
Khodzhakul Formation, Uzbekistan
Material- (CCMGE 49/12176) posterior dentary tooth
Diagnosis- provisionally indeterminate relative to Sinornithoides.
Comments- This tooth was originally distinguished from Troodon formosus by its smaller size, more labiolingually compressed crowns, unserrated mesial carina and smaller distal serrations (Nessov, 1995). However, these characters are also seen in more basal troodontids such as Sinornithoides and Sinusonasus (Averianov and Sues, 2004).
References- Nessov, 1985.
Olshevsky, 1991. A Revision of the Parainfraclass Archosauria Cope, 1869, Excluding the Advanced Crocodylia. Mesozoic Meanderings #2 (1st printing): iv + 196 pp.
Nessov, 1995. Dinosaurs of nothern Eurasia: new data about assemblages, ecology, and paleobiogeography. Institute for Scientific Research on the Earth's Crust, St. Petersburg State University, St. Petersburg 1-156.
Olshevsky, 2000. An Annotated Checklist of Dinosaur Species by Continent. Mesozoic Meanderings #3: 1-157.
Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.

Sinornithoides Russell and Dong, 1993
S. youngi Russell and Dong, 1993
Early Cretaceous
Ejinhoro Formation, Inner Mongolia, China
Holotype- (IVPP V9612) (1.1 m) skull (109 mm), hyoid, atlantal neural arch, fourth cervical centrum (18 mm), fifth cervical vertebra (18 mm), sixth cervical prezygapophysis, ninth cervical vertebra (19.1 mm), ninth cervical rib, tenth cervical vertebra (14.4 mm), tenth cervical rib, first dorsal vertebra (13 mm), first dorsal rib, ten pairs of dorsal ribs, fifteen rows of gastralia, (sacrum- 72 mm) sixth sacral vertebra (12 mm), first caudal vertebra (~11.5 mm), first chevron (16.7 mm), second caudal vertebra (~13.5 mm), second chevron (23.8 mm), third caudal vertebra (14.5 mm), fourth caudal vertebra, fifth caudal vertebra, sixth caudal vertebra, seventh caudal vertebra (11.6 mm), seventh chevron (9.2 mm), eighth caudal vertebra (14 mm), ninth caudal vertebra (17.5 mm), tenth caudal vertebra (21.2 mm), eleventh caudal vertebra (21.5 mm), twelfth caudal vertebra (23 mm), thirteenth caudal vertebra (24.5 mm), fourteenth caudal vertebra (23.9 mm), fifteenth caudal vertebra (23 mm), sixteenth caudal vertebra (22.5 mm), seventeenth caudal vertebra (23.5 mm), eighteenth caudal vertebra (22.9 mm), nineteenth caudal vertebra (24 mm), twentieth caudal vertebra (23.8 mm), twenty-first caudal vertebra (23 mm), twenty-second caudal vertebra (22 mm), twenty-third caudal vertebra (18 mm), twenty-fourth caudal vertebra (22.4 mm), twenty-fifth caudal vertebra (~20 mm), twenty-sixth caudal vertebra (~18 mm), twenty-seventh caudal vertebra (~16.8 mm), chevrons, proximal scapula, coracoids (~30 mm long, 27 mm deep), incomplete furcula, humeri (82.8 mm), radius (59.1 mm), ulna (65 mm), radiale, semilunate carpal, metacarpal I (11.3, 12.1 mm), phalanx I-1 (29.3 mm), manual ungual I (19.7 mm), metacarpal II (37.1 mm), phalanx II-1 (19 mm), phalanx II-2 (28.5, 28.1 mm), manual ungual II (22, 22 mm), metacarpal III (35 mm), phalanx III-1 (4.2 mm), phalanx III-2 (8.2 mm), phalanx III-3 (20.3 mm), manual ungual III (15.5 mm), ventral ilia (73 mm), pubes (89 mm), ischia (47.5 mm), femora (140 mm), tibiae (197.6 mm), fibulae, astragali (19.2 mm wide), distal tarsal III, distal tarsal IV, metatarsal I (~12.3, 12.3 mm), phalanx I-1 (11.4, 10 mm), pedal ungual I (10.7, 9.5 mm), metatarsal II (100.4, 100.6 mm), phalanx II-1 (20.2, 21.7 mm), phalanx II-2 (11.7 mm), pedal ungual II (19 mm), metatarsal III (111 mm), phalanx III-1 (27.6, 23 mm), phalanx III-2 (20, 19.2 mm), phalanx III-3 (16, 15.8 mm), pedal ungual III (14.6 mm), metatarsal IV (110 mm), phalanx IV-1 (17.8, 18.2 mm), phalanx IV-2 (15.7, 13.9 mm), phalanx IV-3 (13, 11.7 mm), phalanx IV-4 (12.5, 13 mm), pedal ungual IV (11.5 mm), metatarsal V (41.8 mm)
Comments- Dong (1997) referred a fragmentary specimen (IVPP V11119) to Sinornithoides sp. nov., but it seems to be more basal.
References- Russell and Dong, 1993. A nearly complete skeleton of a new troodont dinosaur from the Early Cretaceous of the Ordos Basin, Inner Mongolia, People's Republic of China. Canadian Journal of Earth Sciences. 30, 2163-2173.
Dong, 1997. On small theropods from Mazongshan Area, Gansu Province, China. Pp. 13-18. in Dong (ed). Sino-Japanese Silk Road Dinosaur Expedition. China Ocean Press, Beijing. 114 p.
Currie and Dong, 2001. New information on Cretaceous troodontids (Dinosauria, Theropoda) from the People's Republic of China. Canadian Journal of Earth Sciences. 38, 1753-1766.
White, 2009. The subarctometatarsus: intermediate metatarsus architecture demonstrating the evolution of the arctometatarsus and advanced agility in theropod dinosaurs. Alcheringa. 33(1), 1-21.

unnamed clade
Diagnosis- enlarged serrations; mesial carinae of some lateral teeth serrated; distal articular surface of metatarsal III extends far proximally.

unnamed troodontid (Nessov and Golovneva, 1990)
Middle Maastrichtian, Late Cretaceous
Kakanaut Formation, Russia
Material- (ZIN PH 1/28) partial tooth
Diagnosis- (after Averianov and Sues, 2007) no distinct pits between the bases of the distal serrations; larger serrations (1.64/mm) than T. formosus.
Comments- This was referred to cf. Troodon sp. by Nessov and Goloneva (1990) and Nessov (1995), and Troodon cf. formosus by Averianov and Sues (2007) because Troodon is known from the Maastrichtian of Alaska, but the mesial carina is missing so it is unknown if serrations extended apically as in Troodon, or not as in Saurornithoides.
References- Nessov and Golovneva, 1990. [History of the flora, vertebrates and climate in the late Senonian of the north-eastern Koriak Uplands]; pp. 191–212 in V. A. Krasilov (ed.), [Continental Cretaceous of the USSR.] Dal’nevostochnoe Otdelenie AN SSSR, Vladivostok. [Russian]
Nesov, 1992. Maastrichtian Dinosaurs of NE Asia and Climate Changes caused by vertical oceanic circulation. International Conference on Arctic Margins, Abstracts. 43.
Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.

unnamed troodontid (Rodriguez de la Rosa, 1996)
Late Campanian, Late Cretaceous
Cerro del Pueblo Formation, Mexico
Material- (IGM-7710) pedal phalanx II-2 (22.5 mm)
Diagnosis- shaft more elongate than other troodontids; proximoventral heel bifurcated.
Comments- Rodriguez de la Rosa and Cevallos-Ferriz (1998) refer this to the Troodontidae because the collateral ligament pit is centrally placed. This is only seen in Saurornithoides and Troodon though, not more basal forms (IGM 100/44, Sinornithoides, Borogovia). Thus IGM-7710 may be more closely related to the former two genera.
References- Hernandez, Aguillon, Delgado and Gomez, 1995. The Mexican Dinosaur National Monument. Journal of Vertebrate Paleontology. 15(3), 34A.
Rodriguez de la Rosa, 1996. Vertebrate remains from a Late Cretaceous locality (Campanian, Cerro del Pueblo Formation), Coahuila, Mexico. Journal of Vertebrate Paleontology. 16(3), 60A.
Rodriguez de la Rosa and Cevallos-Ferriz, 1998. Vertebrates of the El Pelillal locality (Campanian, Cerro del Pueblo Formation), Southeastern Coahuila, Mexico. Journal of Vertebrate Paleontology. 18, 751-764.

unnamed troodontid (Zinke, 1998)
Kimmeridgian, Late Jurassic
Guimarota Formation, Portugal
Material- (IPFUB GUI D 93-97, 100, 102, 104, 111, 114-116, 156, 190) 14 teeth (~1.02 mm; FABL ~.92 mm)
Comments- These teeth can be identified as troodontid based on their constricted roots, enlarged serrations and hooked distal serrations. The latter are particularily derived characters among troodontids, as is the presence of serrations on most mesial teeth.
Reference- Zinke, 1998, Small theropod teeth from the Upper Jurassic coal mine of Guimarota (Portugal). Palaontologische Zeischrift. 72(1/2), 179-189.

unnamed troodontid (Codrea, Smith, Dica, Folie, Garcia, Godefroit and Van Itterbeecke, 2002)
Late Maastrichtian, Late Cretaceous
Sinpetru Beds, Romania
Material- teeth
Comments- These teeth are short and not recurved, with mesial and distal serration. The distal serrations are tall, enlarged (~5.5/mm) and apically hooked. They may belong to Elopteryx.
Reference- Codrea, Smith, Dica, Folie, Garcia, Godefroit and Van Itterbeecke, 2002. Dinosaur egg nests, mammals and other vertebrates from a new Maastrichtian site of the Hateg Basin (Romania). C. R. Palevol. V. 1, p. 173-180.

unnamed Troodontidae (Averianov and Sues, 2007)
Early Santonian, Late Cretaceous
Yalovach Formation, Tajikistan
Material- (ZIN PH 1/66) anterior dentary tooth
(ZIN PH 2/66) dentary fragment
(ZIN PH 3/66) anterior dentary tooth
(ZIN PH 4/66) anterior maxillary tooth
(ZIN PH 5/66) posterior maxillary tooth
(ZIN PH 7/66) posterior dentary tooth
(ZIN PH 8/66) premaxillary tooth
?(ZIN PH 13/60) tooth
(ZIN PH coll.) at least four teeth
Comments- ZIN PH 13/60 may belong to another taxon because it is unserrated. The dentary fragment ZIN PH 2/66 lacks tooth crowns, so may be referrable to the taxon with serrated teeth or the same one as ZIN PH 13/60.
Reference- Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.

unnamed Troodontidae (Averianov and Sues, 2007)
Early Campanian, Late Cretaceous
Darbasa Formation, Kazakhstan
Material- (ZIN PH 2/67) maxillary tooth
(ZIN PH 3/67) posterior dentary tooth
(ZIN PH 4/67) posterior dentary tooth
(ZIN PH coll.) four teeth
Comments- These teeth were identified as cf. Troodon sp. by Averianov and Nessov (1995) and Nessov (1995). They have 1.82-3.33 serrations per mm on the distal carina, while all but one lack mesial serrations. The mesial serrations on that specimen are smaller than its distal ones (3.33/mm vs. 2.33).
Reference- Averianov and Nessov, 1995. A new Cretaceous mammal from the Campanian of Kazakhstan. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte. 1995, 65-74.
Nessov, 1995. Dinosaurs of nothern Eurasia: new data about assemblages, ecology, and paleobiogeography. Institute for Scientific Research on the Earth's Crust, St. Petersburg State University, St. Petersburg 1-156.
Averianov and Sues, 2007. A new troodontid (Dinosauria: Theropoda) from the Cenomanian of Uzbekistan, with a review of troodontid records from the territories of the former Soviet Union. Journal of Vertebrate Paleontology. 27(1), 87-98.

Troodontidae indet. (Currie and Eberth, 1993)
Early Maastrichtian, Late Cretaceous
Iren Dabasu Formation, Inner Mongolia, China
Material- (AMNH 6570) (subadult) axis, third cervical vertebra (Makovicky, 1995)
(AMNH 21751) distal metatarsal III, distal metatarsal II (Currie and Eberth, 1993)
(AMNH 21772) metatarsal III (Currie and Eberth, 1993)
(AMNH 25570) three vertebrae (AMNH online)
(IVPP 230790-16) metatarsal III (Currie and Eberth, 1993)
Description- AMNH 21751 and 21772 were discovered in the 1920's, provisionally referred to Saurornithoides by Currie and Eberth (1993), then described by Currie and Dong (2001), who identified them as indeterminate troodontids more derived than Sinornithoides. This was based on the proximal extent of the distal articular surface on metatarsal III. IVPP 230790-16 was discovered in 1990, provisionally referred to Saurornithoides (mistakenly as IVPP 230090-16) by Currie and Eberth (1993) , then described by Currie and Dong (2001) who came to the same conclusions as they did for AMNH 21751 and 21772. AMNH 6570 was described by Makovicky (1995). Currie and Eberth also provisionally referred a femur (PIN 2549-100) to Saurornithoides, but Osmolska (1996) has shown it is more similar to Bagaraatan.
Comments- Provisionally referred to Saurornithoides by Currie and Eberth (1993), but said to be an undetermined derived troodontid by Currie and Dong (2001). AMNH 21751 consists of two elements the right size to belong to the same individual, but are different colors, so may not.
References- Currie and Eberth, 1993. Palaeontology, sedimentology and palaeoecology of the Iren Dabasu Formation (Upper Cretaceous), Inner Mongolia, People’s Republic of China. Cretaceous Research. 14 127-144.
Makovicky, 1995. Phylogenetic aspects of the vertebral morphology of Coelurosauria (Dinosauria: Theropoda). M.S. thesis, Univ. Copenhagen, 311pp.
Osmolska, 1996. An unusual theropod dinosaur from the Late Cretaceous Nemegt Formation of Mongolia. Acta Palaeontologica Polonica. 41, 1-38.
Currie and Dong, 2001. New information on Cretaceous troodontids (Dinosauria, Theropoda) from the People's Republic of China. Canadian Journal of Earth Sciences. 38, 1753-1766.

Borogovia Osmolska, 1987
B. gracilicrus Osmolska, 1987
Early Maastrichtian, Late Cretaceous
Nemegt Formation, Mongolia
Holotype- (ZPAL MgD-I/174) incomplete tibiotarsi (280+ mm, 27 mm wide), proximal fibula, distal metatarsal II, phalanx II-1 (32 mm), phalanx II-2 (13 mm), pedal ungual II (31 mm), distal metatarsal III, distal phalanx III-1, phalanx III-2 (23 mm), phalanx III-3 (22 mm), pedal ungual III (15 mm), distal metatarsal IV, phalanx IV-1 (18 mm), phalanx IV-2 (17 mm), phalanx IV-3 (15 mm), phalanx IV-4 (16 mm), pedal ungual IV (21.5 mm)
Comments- This specimen was first mentioned by Osmolska (1982) as Saurornithoides sp. and may be a junior synonym of Zanabazar, as posited by Osmolska (1987). The currently known specimens of each taxon do not overlap.
References- Osmolska, 1982. Hulsanpes perlei n.g.n.sp. (Deinonychosauria, Saurisichia, Dinosauria) from the Upper Cretaceous Barun Goyot Formation of Mongolia. Neües Jahrbuch fur Geologie und Palaontologie Monatschefte. 1982(7), 440-448.
Osmolska, 1987. Borogrovia gracilicrus gen. et sp. n., a new troodontid dinosaur from the Late Cretaceous of Mongolia. Acta Palaeontologica Polonica. 32, 133-150.

Tochisaurus Kurzanov and Osmolska, 1991
T. nemegtensis Kurzanov and Osmolska, 1991
Early Maastrichtian, Late Cretaceous
Nemegt Formation, Mongolia
Holotype- (PIN 551-224) (2.83 m) metatarsal II (233 mm), metatarsal III (232 mm), metatarsal IV (242 mm)
Diagnosis- (after Kurzanov and Osmolska, 1991) proximal surface of metatarsus inclined; strongly reduced metatarsal II.
Comments- This was originally figured by Kurzanov (1987) as an unknown theropod, then identified by Osmolska (1987) as a troodontid. Although Osmolska speculated it might be a specimen of Borogovia, Kurzanov and Osmolska (1991) noted the distal end of metatarsal II is far more reduced in Tochisaurus. Similarly, Tochisaurus differs from Zanabazar in having metatarsal II narrower proximally, and the proximal surface of the metatarsus inclined. It cannot be compared to the earlier Saurornithoides, however.
References- Kurzanov, 1987. Avimimidae and the problem of the origin of birds [in Russian]. Trudy, Sovmestnaa Sovetsko-Mongolskaa paleontologiceskaa ekspedicia. 31, 1-95.
Osmolska, 1987. Borogrovia gracilicrus gen. et sp. n., a new troodontid dinosaur from the Late Cretaceous of Mongolia. Acta Palaeontologica Polonica. 32, 133-150.
Kurzanov and Osmólska, 1991. Tochisaurus nemegtensis gen. et sp. n., a new troodontid (Dinosauria, Theropoda) from Mongolia. Acta Palaeontologia Polonica. 36, 69-76.

Saurornithoides Osborn, 1924
= "Ornithoides" Osborn, 1924
S. mongoliensis Osborn, 1924
= "Ornithoides oshiensis" Osborn, 1924
= Troodon mongoliensis (Osborn, 1924) Paul, 1988
Late Campanian, Late Cretaceous
Djadokhta Formation, Mongolia
Holotype- (AMNH 6516) (1.56 m; 13 kg) incomplete skull (192 mm), three sclerotic plates, incomplete mandibles, ninth dorsal vertebra, tenth dorsal vertebra (23 mm), eleventh dorsal vertebra (22 mm), incomplete twelfth dorsal vertebra (23 mm), (sacrum 147 mm) incomplete first sacral vertebra (23 mm), partial second sacral centrum (24 mm), partial third sacral centrum (25 mm), partial fourth sacral centrum (25 mm), partial fifth sacral vertebra (25 mm), incomplete sixth sacral vertebra (25 mm), incomplete first caudal vertebra (22 mm), incomplete second caudal vertebra (23 mm), partial third caudal vertebra, partial fourth caudal vertebra, incomplete first chevron, partial second chevron, partial third chevron, ilial fragment, incomplete pubes, ischia (114 mm), proximal femur (~198 mm), tibial mold (~243 mm), metatarsal I fragments, phalanx I-1 (16 mm), incomplete pedal ungual I, partial metatarsal II, phalanx II-1 (27.5 mm), phalanx II-2 (14 mm), pedal ungual II (29.3 mm), distal metatarsal III (~139 mm), phalanx III-1 (~33 mm), phalanx III-2 (24 mm), proximal phalanx III-3, partial metatarsal IV, phalanx IV-1 (20.5 mm), proximal phalanx IV-2
Referred- ?(IGM 100/1083) (1.85 m; 21 kg) maxillary fragment, incomplete quadrate, incomplete anterior cervical vertebra, partial anterior dorsal vertebra, sacral fragment, three distal caudal vertebrae, distal tarsal IV, pedal ungual II (34.7 mm), distal metatarsal III, proximal metatarsal IV, four pedal phalanges (Norell and Hwang, 2004)
Late Campanian, Late Cretaceous
Djadokhta equivalent, Inner Mongolia, China
?(IVPP V10599) partial sacrum, caudal vertebrae, chevrons, pelvis (Currie and Dong, 2001)
Diagnosis- More derived than Sinornithoides and Sinusonasus due to the absent promaxillary fenestra, large serrations on teeth, and six sacral vertebrae. Less derived than Zanabazar and Troodon due to the dorsal tympanic recess.
Other diagnoses- Osborn (1924) was the first to publish a diagnosis, but as the specimen was the first troodontid known from more than teeth, the generic diagnosis is now far too generalized. The presence of five pairs of external cranial fenestrae is incorrect, as Osborn did not take the supratemporal fenestrae into account, but six pairs are primitive for tetanurines anyway. The external mandibular fenestra is primitive for archosaurs, while the fairly homodont maxillary series is primitive for an even more inclusive group. The presence of nineteen premaxillary and maxillary teeth is incorrect, as there are actually twenty-three. The "less raptorial" teeth are also found in other maniraptoriforms except dromaeosaurids. Teeth which have only distal serrations are also now known in several other troodontids (e.g. Sinornithoides, Sinusonasus, Zanabazar). Maxillary teeth which lack replacement gaps are also present in Mei, Sinovenator and basal avialans, so may be plesiomorphic. Of his listed "specific characters", the posteriorly increasing size of maxillary teeth, closely spaced dentary teeth, and teeth with a sub-acute tip are common in troodontids. The premaxillary teeth do not decrease in size posteriorly though, as the first tooth is small, the second unpreserved, and the third and fourth subequal (Norell et al., 2009). The illusion of decreasing size is due to the length of the roots which are exposed. Flattened, recurved teeth are primitive for archosaurs
Norell et al. (1009) listed several characters in their diagnosis, as they differ from Zanabazar. While Saurornithoides is smaller than Zanabazar, Norell et al. note all other named troodontids except perhaps Troodon are as well. Norell et al. also distinguish it from Zanabazar by its low tooth count (19 maxillary teeth and ~31-33 dentary teeth), but Sinornithoides (18 maxillary teeth), Sinusonasus (~19 maxillary teeth) and Urbacodon (32 dentary teeth) are similar. A jugal with a straight ventral edge below the front of the orbit is also present in Mei and seemingly Sinornithoides, and is somewhat uncertain in Saurornithoides due to breakage in any case. The dorsal tympanic recess is plesiomorphic, being present in Byronosaurus and Sinovenator as well. Norell et al. note their last listed character (maxillary teeth with only slight posterior increase in height) is also present in Mei, Sinovenator and basal avialans, so may be plesiomorphic.
Comments- A partial sacrum, three mid caudal vertebrae and two partial ilia were originally included in the holotype, but were reidentified as protoceratopsian by Norell et al. (2009) and placed in the new number AMNH 30613. Currie and Peng (1993) described a hindlimb as a possible juvenile Saurornithoides mongoliensis, but Norell et al. believed this specimen to be merely Troodontidae indet., as they stated hindlimb elements were undiagnostic in Saurornithoides and Zanabazar. Yet the extremely slender elements are similar to a basal undescribed troodontid from the same stratigraphic level, while the short flexor lip on metatarsal III is more primitive than Saurornithoides. It is tentatively referred to that unnamed species here. Norell and Hwang (2004) described a fragmentary specimen they provisionally referred to Saurornithoides mongoliensis, as it was identical except for being larger. Norell et al. noted definitive referral was not possible, though they did state the tooth replacement was more similar to Saurornithoides than to Byronosaurus, the only other named troodontid from that formation. IVPP V10599 was mentioned by Currie and Dong as being referrable to Saurornithoides mongoliensis and having a sixth sacral vertebra derived from the caudal series, but details including a rationale for the referral are lacking.
References- Osborn, 1924. The discovery of an unknown continent. Natural History. XXIV, 133-149.
Osborn, 1924. Three new Theropoda, Protoceratops zone, central Mongolia. American Museum Novitates. 144, 1-12.
Russell, 1969. A new specimen of Stenonychosaurus from the Oldman Foramtion of Alberta. Canadian Journal of Earth Sciences. 6, 595-612.
Barsbold, 1974. Saurornithoididae, a new family of small theropod dinosaurs from Central Asia and North America. Palaeontologia Polonica. 30, 5-22.
Paul, 1988. Predatory Dinosaurs of the World. Simon and Schuster Co., New York. 464 pp.
Osmolska and Barsbold, 1990. Troodontidae. In Weishampel, Dodson, and Osmolska (eds). The Dinosauria, Berkeley: University of California Press. 259-268.
Currie and Peng, 1993. A juvenile specimen of Saurornithoides mongoliensis from the Upper Cretaceous of northern China. Canadian Journal of Earth Sciences. 30, 2224-2230.
Currie and Dong, 2001. New information on Cretaceous troodontids (Dinosauria, Theropoda) from the People's Republic of China. Canadian Journal of Earth Sciences. 38, 1753-1766.
Norell and Hwang, 2004. A troodontid dinosaur from Ukhaa Tolgod (Late Cretaceous Mongolia). American Museum Novitates. 3446, 9 pp.
Norell, Makovicky, Bever, Balanoff, Clark, Barsbold and Rowe, 2009. A review of the Mongolian Cretaceous dinosaur Saurornithoides (Troodontidae: Theropoda). American Museum Novitates. 3654, 63 pp.

Zanabazar Norell, Makovicky, Bever, Balanoff, Clark, Barsbold and Rowe, 2009
= "Mongolodon" Franzosa, 2004
Z. junior (Barsbold, 1974) Norell, Makovicky, Bever, Balanoff, Clark, Barsbold and Rowe, 2009
= Saurornithoides junior Barsbold, 1974
= "Mongolodon" junior (Barsboild, 1974) Franzosa, 2004
Early Maastrichtian, Late Cretaceous
Nemegt Formation, Mongolia
Holotype- (IGM 100/1) (2.28 m, 27 kg, adult) skull (280.6 mm), anterior mandibles, (sacrum- 200 mm) first sacral vertebra (~34 mm), second sacral vertebra (~31 mm), third sacral vertebra (31 mm), fourth sacral vertebra (31 mm), fifth sacral vertebra (36 mm), sixth sacral vertebra (36.2 mm), proximal caudal vertebra (~31.5 mm), proximal caudal vertebra (33 mm), proximal caudal vertebra (32 mm), proximal caudal vertebra (32 mm), proximal caudal vertebra (33 mm), proximal caudal vertebra (32.8 mm), mid caudal vertebra (31.5 mm), mid caudal vertebra (34 mm), mid caudal vertebra (37 mm), distal caudal vertebra (38 mm), distal caudal vertebra (38 mm), distal caudal vertebra (39 mm), distal caudal vertebra (39.5 mm), distal caudal vertebra (39.5 mm), two proximal chevrons, mid chevron, five distal chevrons, distal tibia (68 mm wide), astragalocalcaneum, distal tarsal III, distal tarsal IV, proximal metatarsal II, proximal metatarsal III, proximal metatarsal IV
Referred- ?(IGM 100/2) postcrania
Diagnosis- (after Norell et al., 2009) exoccipital forms large part of posttemporal fenestra (unknown in other troodontids except Troodon); deep paroccipital processes, with proximodorsal edge above foramen magnum.
Other diagnoses- Barsbold (1974) originally listed a few characters in his diagnosis. The large size is also seen in Troodon. The maxillary tooth count (19-20) overlaps Saurornithoides (19) and Sinusonasus (~19), while the dentary tooth count (35) is the same as Troodon.
Norell et al. also listed several other characters in their diagnosis. The absent dorsal tympanic recess is shared with Troodon. They note the foramen magnum is more transversely compressed than Troodon, but that Byronosaurus and Sinovenator are similar, making it plesiomorphic. Similarly, the lack of a separate canal for the opthalmic branch of the trigeminal nerve is also seen in Byronosaurus and most dromaeosaurids, meaning it is plesiomorphic as well.
Comments- Contrary to Barsbold (1974), Norell et al. note the teeth lack mesial serrations, the caudal vertebrae are probably not a continuous series, and the distal fibula is unpreserved. However, they also fail to note three proximal caudal vertebrae in their materials list and description. Franzosa (2004) assigns this species to a new genus "Mongolodon" without comment in his unpublished thesis. However, Norell et al. (2009) later redescribed the species and made it the type of their new genus Zanabazar. This was largely done because of the absence of characters supporting a sister relationship with Saurornithoides mongoliensis, though Norell et al. do not explicitly support a closer relationship of either species to Troodon either. Borogovia may be a junior synonym (Osmolska, 1987), as its holotype cannot be compared to IGM 100/1. Tochisaurus is not a junior synonym however (Kurzanov and Osmolska, 1991), though this was proposed as possible by Osmolska.
References- Barsbold, 1974. Saurornithoididae, a new family of small theropod dinosaurs from Central Asia and North America. Palaeontologia Polonica. 30, 5-22.
Osmolska, 1987. Borogrovia gracilicrus gen. et sp. n., a new troodontid dinosaur from the Late Cretaceous of Mongolia. Acta Palaeontologica Polonica. 32, 133-150.
Osmolska and Barsbold, 1990. Troodontidae. In Weishampel, Dodson, and Osmolska, eds.. The Dinosauria, Berkeley: University of California Press: 259-268.
Kurzanov and Osmólska, 1991. Tochisaurus nemegtensis gen. et sp. n., a new troodontid (Dinosauria, Theropoda) from Mongolia. Acta Palaeontologia Polonica. 36, 69-76.
Russell and Dong, 1993. A nearly complete skeleton of a new troodont dinosaur from the Early Cretaceous of the Ordos Basin, Inner Mongolia, People's Republic of China. Canadian Journal of Earth Sciences. 30, 2163-2173.
Franzosa, 2004. Evolution of the Brain in Theropoda (Dinosauria). PhD Thesis. The University of Texas at Austin. 357 pp.
Norell, Makovicky, Bever, Balanoff, Clark, Barsbold and Rowe, 2009. A review of the Mongolian Cretaceous dinosaur Saurornithoides (Troodontidae: Theropoda). American Museum Novitates. 3654, 63 pp.

Troodon Leidy, 1856
= Polyodontosaurus Gilmore, 1932
= Stenonychosaurus Sternberg, 1932
= Pectinodon Carpenter, 1982
T. formosus Leidy, 1856
= Laelaps cristatus Cope, 1876
= Dryptosaurus cristatus (Cope, 1876) Hay, 1902
= Deinodon cristatus (Cope, 1876) Osborn, 1902 non (Marsh, 1892) Hay, 1902
= Dromaeosaurus cristatus (Cope, 1876) Matthew and Brown, 1922
= Polyodontosaurus grandis Gilmore, 1932
= Stenonychosaurus inequalis Sternberg, 1932
= Saurornithoides inequalis (Sternberg, 1932) Carpenter, 1982
= Stegoceras formosum (Leidy, 1856) Olshevsky, 1991
= Troodon cristatus (Cope, 1876) Olshevsky, 1995
= Troodon inequalis (Sternberg, 1932) Snively and Russell, 2002
Late Campanian, Late Cretaceous
Judith River Formation, Montana, US
Holotype- (ANSP 9259) posterior premaxillary tooth
Referred- (AMNH 3954; syntypes of Laelaps cristatus) two maxillary teeth (11 mm)
(AMNH 8519) tooth (Sahni, 1972)
(AMNH 8520) tooth (3.4 mm) (Sahni, 1972)
(AMNH 21760) tooth (AMNH online)
(ANSP 15937) dentary tooth (Fiorillo and Currie, 1994)
(ANSP 15947) maxillary tooth (Fiorillo and Currie, 1994)
(ANSP 15950) maxillary tooth (Fiorillo and Currie, 1994)
(ANSP 15964) dentary tooth (Fiorillo and Currie, 1994)
(ANSP 17642) premaxillary tooth (Fiorillo and Currie, 1994)
(ANSP 17780) premaxillary tooth (Fiorillo and Currie, 1994)
(ANSP 17795) premaxillary tooth (Fiorillo and Currie, 1994)
(ANSP 18005) maxillary tooth (Fiorillo and Currie, 1994)
(MOR 170) vertebra (MOR online)
(MOR 320) tooth (MOR online)
(MOR 993) egg (Varricchio and Jackson, 2004)
Late Campanian, Late Cretaceous
Oldman Formation of the Judith River Group, Alberta, Canada
(RTMP 89.77.5) tooth (Ryan and Russell, 2001)
(RTMP 94.157.1) eggshells (Zelenitsky, Modesto and Currie, 2002)
(RTMP 94.157.2) eggshells (Zelenitsky, Modesto and Currie, 2002)
(RTMP 94.157.4) eggshells (Zelenitsky, Modesto and Currie, 2002)
(RTMP 94.157.5) eggshells (Zelenitsky, Modesto and Currie, 2002)
(RTMP 138.319) tooth (Ryan, 2003)
teeth (Ryan and Russell, 2001)
(embryos and adults) material (Zelenitsky, Modesto and Currie, 2002)
Late Campanian, Late Cretaceous
Dinosaur Park Formation of the Judith River Group, Alberta, Canada
(AMNH 6174) frontals, parietals, laterosphenoid (Russell, 1969)
(AMNH 21598) tooth (AMNH online)
(AMNH 21714) tooth (AMNH online)
(CMN 199) distal tibia (58.6 mm wide), astragalus (Russell, 1969)
(CMN 1267) premaxillary tooth (Lambe, 1902)
(CMN 1650) distal manual phalanx, pedal ungual I (52 mm), phalanx II-1 (47.6 mm), phalanx II-2 (24.8, 24.6 mm), pedal ungual II (~70 mm), pedal ungual IV (~45 mm) (Russell, 1969)
(CMN 2506) pedal phalanx II-1 (Russell, 1969)
(CMN 8539, holotype of Stenonychosaurus inequalis) six distal caudal vertebrae, metacarpal I (36.5 mm), distal phalanx I-1, distal metacarpal II, partial phalanx II-1, distal manual phalanx, distal tibia, astragalus, metatarsal I, phalanx I-1 (~29 mm), pedal ungual I (~45 mm), metatarsal II (202.4 mm), phalanx II-1 (~50.5 mm), phalanx II-2 (29 mm), pedal ungual II, metatarsal III (253.6 mm), phalanx III-1 (~66 mm), phalanx III-2 (41.2 mm), phalanx III-3 (39.3 mm), pedal ungual III (~55 mm), metatarsal IV (244.5 mm), phalanx IV-1 (~34.2 mm), phalanx IV-2 (~28.3 mm), phalanx IV-3 (~23.6 mm), phalanx IV-4 (~24.5 mm), pedal ungual IV (~47 mm) (Sternberg, 1932)
(CMN 8540; holotype of Polyodontosaurus grandis) dentary (117.5 mm) (Gilmore, 1932)
(CMN 12340) postorbital, frontals, parietals, basioccipital, basisphenoid, dorsal centrum fragment, four dorsal ribs, seven gastralia, three distal caudal vertebra fragments, three chevrons, proximal radius, ulnae (one distal) (131 mm), semilunate carpal, incomplete manual phalanx II-1, manual ungual, incomplete femur, astragali, metatarsal I, phalanx I-1 (26.3 mm), pedal ungual I (46.5 mm), metatarsal II fragments, phalanx II-1 (46.7 mm), pedal ungual II (65, 66 mm), metatarsal III fragments, phalanx III-1, phalanx III-3 (32.8 mm), pedal ungual III, metatarsal IV fragments, phalanx IV-1 (33.5 mm), phalanx IV-2 (27.3 mm), pedal ungual IV (~43 mm) (Russell, 1969)
(CMN 12392) anterior maxilla, fragments (Russell, 1969)
(CMN 12425) astragalus (58.4 mm wide) (Russell, 1969)
(CMN 12433) ulna (138 mm) (Russell, 1969)
(CMN 12434) pedal phalanx II-1 (Russell, 1969)
(CMN coll.) distal metacarpal I (?), astragalus, calcaneum(?), distal metatarsal I (?), pedal ungual II (Lambe, 1902)
(PMAA P67.14.39) partial dentary (Sues, 1977)
(ROM 1445) partial dentary, second dentary tooth, thirteenth dentary tooth, twentieth dentary tooth (Russell, 1948)
(RTMP 65.23.32) maxillary tooth (10 mm) (Currie, Rigby and Sloan, 1990)
(RTMP 67.14.39) partial dentary, fourteenth dentary tooth (Sues, 1977)
(RTMP 79.8.1) frontals, parietals, laterosphenoid (Currie, 1985)
(RTMP 79.8.635) (juvenile) posterior dentary tooth (4 mm) (Currie, 1987)
(RTMP 79.8.1171) tooth (Baszio, 1997)
(RTMP 80.16.1473) parietals (Currie, 1985)
(RTMP 80.16.1478) frontals, mesethmoid (Currie, 1985)
(RTMP 81.22.66) (Currie, 1985)
(RTMP 82.16.124) frontals, parietals (Currie, 1985)
(RTMP 82.16.138) partial dentary (Currie, 1987)
(RTMP 82.16.282) premaxillary tooth (Currie, 1987)
(RTMP 82.19.23) lacrimal, postorbitals, squamosals, frontals, parietals, braincase (Currie, 1985)
(RTMP 82.19.151) partial dentary (Currie, 1987)
(RTMP 82.20.259) premaxillary tooth (Currie, 1987)
(RTMP 83.12.11) dentary tooth (Currie, Rigby and Sloan, 1990)
(RTMP 83.36.214) maxillary tooth (Currie, Rigby and Sloan, 1990)
(RTMP 83.36.215) tooth (Currie, Rigby and Sloan, 1990)
(RTMP 83.45.7) maxillary tooth (Currie, Rigby and Sloan, 1990)
(RTMP 83.45.8) tooth (Currie, Rigby and Sloan, 1990)
(RTMP 84.65.1) distal metatarsal II, incomplete metatarsal III, distal metatarsal IV (Wilson and Currie, 1985)
(RTMP 85.6.3) premaxillary tooth (Currie, Rigby and Sloan, 1990)
(RTMP 85.6.186) maxillary tooth (Currie, Rigby and Sloan, 1990)
(RTMP 86.36.4) frontal (Currie, 1987)
(RTMP 86.36.457) incomplete braincase (Currie and Zhao, 1993)
(RTMP 86.49.10) frontal (Currie, 1987)
(RTMP 86.54.66) premaxillary tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 86.177.8) maxillary tooth (Sankey, Brinkman, Guenther and Currie, 2002)
(RTMP 88.50.58) tooth (Baszio, 1997)
(RTMP 88.96.2) maxillary tooth (Currie, Rigby and Sloan, 1990)
(RTMP 89.36.268) tooth (Ryan and Russell, 2001)
(RTMP 89.76.50) tooth (Baszio, 1997)
(RTMP 89.77.5) tooth (Baszio, 1997)
(RTMP 89.89.4) tooth (Baszio, 1997)
(RTMP 89.116.63) tooth (Baszio, 1997)
(RTMP 90.34.1) tooth (Baszio, 1997)
(UA 5282) frontal (Russell, 1969)
(UA 5284) distal metatarsal III (Russell, 1969)
(YPM PU 23414) parietals (Currie, 1985)
teeth (Brinkman, 1990)
Campanian, Late Cretaceous
Two Medicine Formation, Montana, US
(MOR 246) nest (Horner and Weishampel, 1988)
....(MOR 246-1) (embryo) teeth, two cervical centra (4.4 mm), cervical neural arch, sacral centrum (5.1 mm), scapula (14.7 mm), fragmentary coracoid, humerus (20.3 mm), partial tibiae, partial fibula, egg
....(MOR 246-2) (embryo) humerus, egg
....(MOR 246-3) egg
....(MOR 246-5) (embryo) bone, egg
....(MOR 246-7) (embryo) bone, egg
....(MOR 246-8) (embryo) femur, egg
....(MOR 246-9) (embryo) bone, egg
....(MOR 246-10) (embryo) bone, egg
....(MOR 246-11) (embryo) (skull ~50 mm) maxilla (~18 mm), quadrate (12.1 mm), basioccipital, teeth (1 mm), vertebrae, ilia, pubes (~23 mm), ischial fragments, femur (34.9 mm), tibiae (46 mm), partial fibula, metatarsal II, metatarsal III, metatarsal IV (33.5 mm)
....(MOR 246-12) egg
....(MOR 246-13) (embryo) bone, egg
....(MOR 246-14) egg
....(MOR 246-15) egg
....(MOR 246-16) (embryo) bone, egg
....(MOR 246-17) (embryo) bone, egg
....(MOR 246-18 (embryo) bone, egg
(MOR 247) egg (Varricchio, Horner and Jackson, 2002)
(MOR 299) eggs (Varricchio, Horner and Jackson, 2002)
(MOR 323) tooth (MOR online)
(MOR 363-7-4-83-1) nest, twenty-two eggs (Varricchio, Jackson, Borkowski and Horner, 1997)
(MOR 393) nest, twenty-two eggs (Varricchio, Horner and Jackson, 2002)
(MOR 430) partial skeleton including premaxilla, caudal vertebrae, femur (Currie, Rigby and Sloan, 1990)
(MOR 493) metatarsals, pedal phalanges (MOR online)
(MOR 510) tooth (MOR online)
(MOR 511) teeth (MOR online)
(MOR 512) teeth (MOR online)
(MOR 513) teeth (MOR online)
(MOR 553) anterior dorsal vertebra, distal caudal vertebrae (Makovicky, 1995)
(MOR 553-1) metatarsal II, metatarsal III, metatarsal IV (Varricchio, 1993)
(MOR 553-2) metatarsal (Varricchio, 1997)
(MOR 553-6.21.9) fourth cervical vertebra (Makovicky, 1995)
(MOR 553-7.16.0.61) femur (Varricchio, 1993)
(MOR 553-7.21.92.46) (adult) ninth or tenth cervical vertebra (Makovicky, 1995)
(MOR 553-7.24.8.64) tibia (425 mm) (Varricchio, 1993)
(MOR 553-7.28.91.236) tenth cervical vertebra (Makovicky, 1995)
(MOR 553-7.20.91.120) anterior dorsal vertebra (Makovicky, 1995)
(MOR 553-7.23.91.36) first caudal vertebra (Makovicky, 1995)
(MOR 553-8.3.92.141) (adult) eighth cervical vertebra (Makovicky, 1995)
(MOR 553-8.8.92.186) first dorsal vertebra (Makovicky, 1995)
(MOR 553-8.10.92.203) (adult) twelfth dorsal vertebra (Makovicky, 1995)
(MOR 553-8.11.92.204) third cervical vertebra (Makovicky, 1995)
(MOR 553-8.12.92.222) (juvenile) eighth or ninth cervical vertebra (Makovicky, 1995)
(MOR 553-8.19.92.212) fourth cervical vertebra (Makovicky, 1995)
(MOR 553-8.20.92.305) (adult) sixth or seventh dorsal vertebra (Makovicky, 1995)
(MOR 553D) partial sacrum (Makovicky, 1995)
(MOR 553L) ischium (Hutchinson, 2001)
(MOR 553S) pubis, ischium, femur (Hutchinson, 2001; 2001)
(MOR553S-7-21-92-47) maxilla (MOR online)
(MOR553S-8-2-91-303) humerus (MOR online)
(MOR553S-8-2-92-131) braincase (MOR online)
(MOR553S-8-12-92-219) ulna (MOR online)
(MOR 558) braincase, three cervical vertebrae, elements (MOR online)
(MOR 563) skeleton including tibia, metatarsal III (Varricchio, 1993)
?(MOR 564) (embryo) maxilla (MOR online)
?(MOR 584) partial skeleton (MOR online)
(MOR 615) eggs (MOR online)
(MOR 646) jaw fragment (MOR online)
(MOR 675) eggs (Varricchio, Horner and Jackson, 2002)
(MOR 676) eggs (Varricchio, Horner and Jackson, 2002)
(MOR 702) two eggs (Varricchio and Jackson, 2004)
(MOR 748) nine proximal caudal vertebrae, eight distal caudal vertebrae, partial pelvis, femur (483 mm), tibia (407 mm), fibula, astragalus, metatarsus (223 mm), four pedal phalanges, nest, at least ten eggs (Varricchio, Jackson, Borkowski and Horner, 1997)
(MOR 750) eggs (Varricchio, Horner and Jackson, 2002)
(MOR 796) five vertebrae, partial ribs (MOR online)
(MOR 963) nest, twenty-four eggs (Varricchio, Jackson, Borkowski and Horner, 1997)
(MOR 964) eggs (MOR online)
(MOR 1006) partial egg (MOR online)
(MOR 1115) twenty-four eggs (MOR online)
(MOR 1138) eggs (MOR online)
(MOR 1139) eggs (Varricchio, Horner and Jackson, 2002)
(MOR 1170) tibia (MOR online)
(YPM PU 22445) (YPM online)
(YPM PU 23246-23248) (YPM online)
(YPM PU 22544) (Hirsch and Quinn, 1990)
(YPM PU 22594) (Hirsch and Quinn, 1990)
(YPM PU 23259) (YPM online)
(YPM PU 23408) (YPM online)
(YPM PU 23409) (YPM online)
Diagnosis- (after Currie, 1987; compared to Saurornithoides and Zanabazar) round anterior border of antiorbital fenestra; sculpturing less extensive on nasal process of maxilla; postorbital region of skull longer; no sulcus between parasphenoid capsule and rectangular platform between basipterygoid processes; mesethmoid located further anteriorly; very strong, caudoventrally shifted basal tubera; otic recess extends further posteroventrally; dentary symphysis more extensive; mesial serrations extend to tip of carina on maxillary teeth.
Comments- The supposed Struthiomimus manual ungual in plate XV figure 10-11 of Lambe (1902) is not ornithomimid and may be a Troodon pedal ungual II instead. Found with this and apparently similar unguals and manual phalanges were an astragalus, calcaneum, pedal phalanges and two elements identified by Lambe as distal ends of metacarpal I and metatarsal I. A metatarsal I would exclude ornithomimids from consideration, but a calcaneum would exclude troodontids. It's probable some material was incorrectly associated or misidentified.
Ornithischian or theropod?- Troodon was originally identified as a lizard by Leidy (1856) based on the holotype tooth, but reidentified as a theropod by Cope (1877). Nopcsa (1901) and Hay (1902) placed it in Megalosauridae. Brown (1908) placed it in Ankylosauridae, while Gilmore (1924) believed it was a pachycephalosaurid and a senior synonym of Stegoceras. Thus pachycephalosaurs were classified under Gilmore's new family Troodontidae until Sternberg (1945) placed Troodon back in Theropoda and named Pachycephalosauridae. Russell (1948) described a partial dentary (ROM 1445) of Troodon, assigning it to Troodontidae within the Theropoda. A further confusion with ornithischians occured when Galton (1983) suggested "Laosaurus" minimus should be assigned to Troodon and that the latter is a carnivorous ornithopod (first suggested by Baird, 1981). Galton cited pers. comm. with Horner alluding to undescribed Two Medicine Formation material. The latter turned out to be adults of the ornithopod Orodromeus (Horner and Weishampel, 1988) associated with Troodon teeth, eggs and embryos (Horner and Weishampel, 1996). The idea of Troodon as a carnivorous ornithopod was never established in the technical literature, but was widespread in the popular literature in the 1980's. Instead, it was almost always assigned to Theropoda after 1945.
Laelaps cristatus- Cope (1876) described two teeth as a new species of Laelaps (in which he placed all Judithian theropods). Once Marsh provided the replacement name Dryptosaurus for the preoccupied Laelaps, Hay (1902) moved cristatus to that genus. Osborn (1902) meanwhile referred it to Deinodon, though this is not the same taxon as Hay's (1902) Deinodon cristatus, which was a new combination of Aublysodon cristatus, a tyrannosaurid premaxillary tooth. Matthew and Brown (1922) questionably referred the species to their new genus Dromaeosaurus, probably based on size, for it was the smallest of their 'deinodontids'. Olshevsky (1995) most recently referred it to Troodon, though most workers have ignored it. This tooth can indeed be identified as Troodon by its large serrations (2/mm distally, and slightly smaller mesially), presence of mesial serrations and absence of longitudinal ridges. The size (FABL 6 mm) and BW/FABL (.50) are also comparable to Troodon maxillary teeth (Currie et al., 1990), as is the height/FABL (1.83). The serrations are smaller than in premaxillary teeth, which is why Cope kept it separate from Troodon (at the time only known from the type premaxillary tooth). The tooth is larger than dentary teeth, posterior examples of which also differ in lacking mesial serrations. As it is from the same formation as T. formosus and lacks distinguishing characters, it is referred to that species here.
Polyodontosaurus grandis- Sternberg collected a dentary (CMN 8540) from the same formation as Leidy's specimen, which Gilmore (1932) described as a new genus of lizard- Polyodontosaurus. Sternberg later (1951) assigned this genus to Troodontidae, noting it may be congeneric with Troodon. The latter synonymization was formalized by Romer in 1966, who assigned both to the Coeluridae. On the other hand, Russell (1969) synonymized Polyodontosaurus with Stenonychosaurus inequalis in the Troodontidae.
Stenonychosaurus and Saurornithoides- Sternberg (1932) named Stenonychosaurus inequalis as a coelurid, based on a fragmentary skeleton (CMN 8539). Sternberg later (1951) suggested Stenonychosaurus and Troodon might be synonymous, but no comparable elements were known which could prove this. Russell (1969) described several specimens found in 1968 as Stenonychosaurus inequalis, assigning it to the Troodontidae along with Saurornithoides and Troodon. He did not synonymize Troodon with Stenonychosaurus or Saurornithoides due to the fragmentary condition of the former. Ostrom (1969) assigned both Saurornithoides and Stenonychosaurus to the Dromaeosauridae based on their raptorial second pedal digit, though perhaps deserving subfamilial status. Barsbold (1974) noted differences between the holotype of Troodon and teeth of Saurornithoides, while feeling the cranial and postcranial resemblences between Stenonychosaurus and Saurornithoides justified a close relationship. He assigned the latter two genera to his new family Saurornithoididae, while retaining Troodon in Troodontidae. This was followed until Currie (1987). Sues (1977) described two new dentaries as saurornithoidids, though he was uncertain if they belonged to Stenonychosaurus or Saurornitholestes (which was assigned to Dromaeosauridae once he described it the next year). Stenonychosaurus was generally used for the Dinosaur Park troodontid through the 1980's (e.g. Currie, 1985), though Carpenter (1982) synonymized it with Saurornithoides, as Saurornithoides inequalis. This was done without justification however, referencing a Carpenter and Paul in prep. publication which never emerged. Paul did later (1988) synonymize Saurornithoides with Troodon (including Stenonychosaurus), but this is a subjective decision which has not been accepted by later authors.
Estes (1964) originally referred several teeth from the Lance Formation of Wyoming to Saurornithoides sp.. Carpenter (1982) named Pectinodon bakkeri from the same formation, believing some of Estes' specimens to be referrable to that species, some to his new combination Saurornithoides inequalis, and others to an unnamed third taxon. He assigned Pectinodon to the Saurornithoididae.
Currie's breakthrough- Currie (1987) cleared up the American troodontid situation, determining the differences between known dentaries were ontogenetic, and dental differences between Troodon, ROM 1445, Saurornithoides and the Lance Formation specimens were largely due to variation within the tooth row. Troodon's holotype is a premaxillary tooth, the teeth of Saurornithoides which Barsbold compared were maxillary (as were Carpenter's Saurornithoides inequalis examples), Pectinodon was based on posterior dentary teeth, while ROM 1445 contains a few dentary teeth. Currie described intermediates between all of these morphologies, although he noted the maxillary mesial serrations are more extensive in Troodon than Saurornithoides, extending to the tip of the tooth. He synonymized Stenonychosaurus inequalis and Polyodontosaurus grandis with Troodon formosus, and provisionally did the same for Pectinodon bakkeri. This has remained the consensus, along with the assignment of Saurornithoides, Troodon and related taxa to the Troodontidae.
Overlumped?- Recently the concept of all Campanian-Maastrichtian North American troodontids being one taxon has been questioned. Currie et al. (1990) noted that though Horseshoe Canyon Formation troodontid teeth are essentially identical to those from the Judith River Group/Formation, teeth from the Frenchman, Hell Creek, Lance, Prince Creek and Scollard Formations are different and may prove to be separate species. Baszio (1997) elaborated, describing differences between teeth from the Judith River, Horseshoe Canyon and Scollard Formations. Olshevsky (1991) created the new combination Troodon bakkeri for the Lance Formation material, while several papers have used the combination Troodon inequalis for the Dinosaur Park Formation taxon (Snively, 2002; Osmolska, 2004; Currie, 2005). Currie (2005) stated that it is more conservative to retain inequalis for Dinosaur Park specimens, but keeping taxa separate based on a political boundary (Montana vs. Alberta) has no biological value. Sankey et al. (2002) have split Dinosaur Park Formation troodontids into Troodon formosus and cf. Troodontidae indet., with the latter being a rare form only present in some formations and distinguished by various dental characters. If they are correct, most of the non-dental specimens (including the Stenonychosaurus holotype and CMN 12340) could not be definitively assigned to either taxon, and many poorly or undescribed Troodon teeth could end up not being referrable to that genus.
Troodon eggs and embryos- Horner (1982) first reported ten nests in the Two Medicine Formation which he ascribed to ornithopods, "closely allied to the Hypsilophodontidae". Horner and Weishampel later (1988) described a new genus of ornithopod from the site, Orodromeus makelai. They believed abundant nest with eggs and embryos belonged to Orodromeus, though this was disproven by Horner and Weishampel (1996) due to the small size of adult Orodromeus and the reidentification of an embryo as Troodon. Zelenitsky and Hillis (1996) named eggs from the Oldman Formation of Alberta Prismatoolithus levis (Prismatoolithidae), while Zelenitsky (2000) identified the Two Medicine Formation Troodon eggs as belonging to this oospecies as well. Most of the publications dealing with Troodon since that time have concerned these nests, eggs and embryos.
One confusing aspect is that Continuoolithus canadensis eggs were provisionally assigned to Troodon by Horner (1984), based on an embryo. This was followed by Hirsch and Quinn (1990) and Horner (1994), until 1996. Horner (1997) found the embryo to be indeterminate, while Varricchio and Jackson (2004) found the eggshell to be theropod. The precise identity of Continuoolithus is still unknown.
Reinterpreted records- Although Currie et al. (1990) reported Troodon from the Milk River Formation, Baszio (1997) notes the ROM specimens noted were collected in the Milk Creek area, but probably in the Judith River Group. A large sample of theropod teeth from the Milk River Formation did not include Troodon.
Rowe et al. (1992) and Sankey (1997, 1998) identified Troodon in the Aguja Formation of Texas based on teeth (TMM 43057-323 and LSUMG 140:6117 respectively), but these were later identified as pachycephalosaurian by Sankey (2001). This means Troodon is unknown from the Aguja Formation.
References- Leidy, 1856. Notices of remains of extinct reptiles and fishes, discovered by Dr. F. V. Hayden in the bad lands of the Judith River, Nebraska Territory. Proceedings of the Academy of Natural Sciences of Philadelphia. 8, 72-73.
Cope, 1876. On some extinct reptiles and Batrachia from the Judith River and Fox Hills Beds of Montana. Proceedings of the Academy of Natural Sciences of Philadelphia. 28, 340-359.
Cope. 1877. Report on the geology of the region of the Judith River, Montana, and on vertebrate fossils obtained on or near the Missouri River. Bulletin of the United States Geological and Geographical Survey. 3(3), 565-597.
Nopcsa, 1901. Synopsis un Abstammung der Dinosaurier. Foldtani Kozlony (Budapest). 31, 247-288.
Hay, 1902. Bibliography and Catalogue of Fossil Vertebrata of North America. U.S. Geological Survey Bulletin. 179, 868 pp.
Lambe, 1902. New genera and species from the Belly River Series (mid-Cretaceous). Contributions to Canadian Palaeontology, Geological Survey of Canada. 3, 23-81.
Osborn, 1902. On Vertebrata of the Mid-Cretaceous of the Northwest Territory. I: Distinctive characters of the Mid-Cretaceous fauna. Contrib. Canad. Pal. III. 1-21.
Matthew and Brown, 1922. The family Deinodontidae, with notice of a new genus from the Cretaceous of Alberta. Bulletin of the American Museum of Natural History. 46(6), 367-385.
Gilmore, 1924. On Troodon validus, an orthopodous dinosaur from the Belly River Cretaceous of Alberta, Canada. Department of Geology, University of Alberta Bulletin. 1, 1-43.
Gilmore, 1932. A new fossil lizard from the Belly River Formation of Alberta. Transactions of the Royal Society of Canada, section 4, series 3. 16, 117-119.
Sternberg, 1932. Two new theropod dinosaurs from the Belly River Formation of Alberta. Canadian Field-Naturalist. 46(5), 99-105.
Russell, 1948. The dentary of Troödon, a genus of theropod dinosaurs. Journal of Paleontology. 22(5), 625-629.
Sternberg, 1945. Pachycephalosauridae proposed for domeheaded dinosaurs, Stegoceras lambei n. sp., described. Journal of Paleontology. 19, 534-538.
Sternberg, 1951. The lizard Chamops from the Wapiti Formation of northern Alberta; Polyodontosaurus grandis not a lizard. National Museum of Canada Bulletin. 123, 256-258.
Estes, 1964. Fossil vertebrates from the Late Cretaceous Lance Formation, eastern Wyoming. University of California Publications in Geological Sciences. 49, 1-180.
Romer, 1966. Vertebrate Paleontology, 3rd edition. University of Chicago Press, Chicago. 1-468.
Ostrom, 1969. Osteology of Deinonychus antirrhopus, an unusual theropod from the Lower Cretaceous of Montana. Peabody Museum of Natural History Bulletin. 30, 1-165.
Russell, 1969. A new specimen of Stenonychosaurus from the Oldman Foramtion of Alberta. Canadian Journal of Earth Sciences. 6, 595-612.
Sahni, 1972. The vertebrate fauna of the Judith River Formation, Montana. Bulletin of the AMNH. 147.
Barsbold, 1974. Saurornithoididae, a new family of small theropod dinosaurs from Central Asia and North America. Palaeontologia Polonica. 30, 5-22.
Sues, 1977. Dentaries of small theropods from the Judith River Formation (Campanian) of Alberta, Canada. Canadian Journal of Earth Sciences. 14, 587-592.
Baird, 1981. Princeton University. Society of Vertebrate Paleontology News Bulletin. 121, 21-22.
Carpenter, 1982. Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod. Contributions to Geology, University of Wyoming. 20(2), 123-134.
Horner, 1982. Evidence for colonial nesting and "site fidelity" among ornithischian dinosaurs. Nature. 297, 675-676.
Galton, 1983. The cranial anatomy of Dryosaurus, a hypsilophodontid dinosaur from the Upper Jurassic of North America and East Africa, with a review of hypsilophodontids from the Upper Jurassic of North America. Geologica et Palaeontologica. 17, 207-243.
Horner, 1984. The nesting behavior of dinosaurs. Scientific American. 250, 130-137.
Currie, 1985. Cranial anatomy of Stenonychosaurus inequalis (Saurischia, Theropoda) and its bearing on the origin of birds. Canadian Journal of Earth Sciences. 22(1), 643-658.
Wilson and Currie, 1985. Stenonychosaurus inequalis (Saurischia: Theropoda) from the Judith River (Oldman) Formation of Alberta: new findings on metatarsal structure. Canadian Journal of Earth Sciences. 22(1), 813–817.
Currie, 1987. Bird-like characteristics of the jaws and teeth of troodontid theropods (Dinosauria, Saurischia). Journal of Vertebrate Paleontology. 7, 72-81.
Currie, 1987. Theropods of the Judith River Formation. Occasional Paper of the Tyrrell Museum of Palaeontology. 3, 52-60.
Horner and Weishampel, 1988. A comparative embryological study of two ornithischian dinosaurs. Nature. 332, 256-257.
Fiorillo, 1989. The vertebrate fauna from the Judith River Formation (Late Cretaceous) of Wheatland and Golden Valley Counties, Montana. The Mosasaur. 4, 127-142.
Brinkman, 1990. Paleoecology of the Judith River Formation (Campanian) of Dinosaur Provincial Park, Alberta, Canada: Evidence from vertebrate microfossil localities. Palaeogeography, Palaeoclimatology, Palaeoecology. 78, 37-54.
Currie, Rigby and Sloan, 1990. Theropod teeth from the Judith River Formation of southern Alberta, Canada. in Carpenter and Currie (eds.). Dinosaur Systematics: Perspectives and Approaches. Cambridge University Press, New York. pp. 107-125.
Hirsch and Quinn, 1990. Eggs and eggshell fragments from the Upper Cretaceous Two Medicine Formation of Montana. Journal of Paleontology. 10, 491-511.
Olshevsky, 1991. A Revison of the Parainfraclass Archosauria Cope, 1869, Excluding the Advanced Crocodyila. Mesozoic Menanderings #2 (1st printing). iv + 196pp.
Varricchio and Currie, 1991. New theropod finds from the Two Medicine Formation (Campanian) of Montana. Journal of Vertebrate Paleontology. 11(3), 59A.
Rowe, Ciffelli, Lehman and Weil, 1992. The Campanian Terlingua local fauna, with a summary of other vertebrates from the Aguja Formation, Trans-Pecos, Texas. Journal of Vertebrate Paleontology. 12, 472-493.
Varricchio, 1992. Taphonomy and Histology of the Upper Cretaceous Theropod Dinosaur Troodon formosus: Life history Implications. Journal of Vertebrate Paleontology. 12(3), 57A.
Currie and Zhao, 1993. A new troodontid (Dinosauria, Theropoda) braincase from the Dinosaur Park Formation (Campanian) of Alberta. Canadian Journal of Earth Sciences. 30(10-11), 2234-2247.
Varricchio, 1993. Bone microstructure of the Upper Cretaceous theropod dinosaur Troodon formosus. Journal of Vertebrate Paleontology. 13(1), 99-104.
Fiorillo and Currie, 1994. Theropod teeth from the Judith River Formation (Upper Cretaceous) of south-central Montana. Journal of Vertebrate Paleontology. 14(1), 74-80.
Horner, 1994. Comparative taphonomy of some dinosaur and extant bird colonial nesting grounds. in Carpenter, Hirsch and Horner (eds.). Dinosaur Eggs and Babies. Cambridge University Press. 116-123.
Makovicky, 1995. Phylogenetic aspects of the vertebral morphology of Coelurosauria (Dinosauria: Theropoda). M.S. thesis, Univ. Copenhagen, 311pp.
Olshevsky, 1995. The origin and evolution of the tyrannosaurids. Kyoryugaku Saizensen [Dino-Frontline]. 9, 92-119 (part 1); 10, 75-99 (part 2) [in Japanese].
Horner Weishampel, 1996. A comparative embryological study of two ornithischian dinosaurs - a correction. Nature. 383, 103.
Zelenitsky and Hills, 1996. An egg clutch of Prismatoolithus levis oosp. nov. from the Oldman Formation (Upper Cretaceous), Devil’s Coulee, southern Alberta. Canadian Journal of Earth Science. 33(1), 127-131.
Baszio, 1997. Investigations on Canadian dinosaurs: systematic palaeontology of isolated dinosaur teeth from the Latest Cretaceous of south Alberta, Canada. Courier Forschungsinstitut Senckenberg. 196, 33-77.
Horner, 1997. Rare preservation of an incompletely ossified fossil embryo. Journal of Vertebrate Paleontology. 17, 431-434.
Sankey, 1997. Late Cretaceous vertebrate paleontology and Paleoecology, Upper Aguja Formation, Big Bend National Park, Texas. Journal of Vertebrate Paleontology. 17(3), 73A.
Varricchio, Jackson, Borkowski and Horner, 1997. Nest and egg clutches of the dinosaur Troodon formosus and the evolution of avian reproductive traits. Nature. 385, 247-250.
Sankey, 1998. Vertebrate paleontology and magnetostratigraphy of the upper Aguja Formation (late Campanian), Talley Mountain area, Big Bend National Park, Texas. Unpublished Ph.D. dissertation. Louisiana State University, Baton Rouge. 263 pp.
Varricchio, Jackson and Trueman, 1999. A nesting trace with eggs for the Cretaceous theropod dinosaur Troodon formosus. Journal of Vertebrate Paleontology. 19, 91-100.
Varricchio and Jackson, 2000. Physiological implications of reproductive behavior in the dinosaur Troodon formosus. Journal of Vertebrate Paleontology. 20(3), 75A.
Zelenitsky, 2000. Dinosaur eggs from Asia and North America. Journal of the Paleontological Society of Korea, Special Publication. 4, 13-26.
Horner, Padian and de Ricqles, 2001. Comparative osteohistology of some embryonic and perinatal archosaurs: developmental and behavioral implications for dinosaurs. Paleobiology. 27, 39-58.
Hutchinson, 2001. The evolution of pelvic osteology and soft tissues on the line to extant birds (Neornithes). Zoological Journal of the Linnean Society. 131, 123-168.
Hutchinson, 2001. The evolution of femoral osteology and soft tissues on the line to extant birds (Neornithes). Zoological Journal of the Linnean Society. 131, 169-197.
Ryan and Russell, 2001. The dinosaurs of Alberta (exclusive of Aves). in Tanke and Carpenter (eds.). Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie. Indiana University Press, Bloomington, Indiana. pp. 279-297.
Sankey, 2001. Late Campanian southern dinosaurs, Aguja Formation, Big Bend, Texas. Journal of Vertebrate Paleontology. 75(1), 208-215.
Varricchio, 2001. "Beautiful wounding tooth": ontogeny and osteology in the theropod Troodon formosus. Journal of Vertebrate Paleontology. 21(3), 110A.
Varricchio, Horner and Jackson, 2002. Embryos and eggs for the Cretaceous theropod Troodon formosus. Journal of Vertebrate Paleontology. 22, 564-576.
Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.
Snively and Russell, 2002. Kinematic model of tyrannosaurid (Dinosauria: Theropoda) arctometatarsus function. 255(2), 215-227.
Zelenitsky, Modesto and Currie, 2002. Bird-like characteristics of troodontid theropod eggshell. Cretaceous Research. 23, 297-305.
Ryan, 2003. Taxonomy, systematics and evolution of centrosaurine ceratopsids of the Campanian Western Interior basin of North America. Unpublished PhD thesis. Department of Biological Sciences, Calgary, Alberta. 578pp.
Osmolska, 2004. Evidence on relation of brain to endocranial cavity in oviraptorid dinosaurs. Aacta Paleontologica Polonica. 49(2), 321-324.
Varricchio and Jackson, 2004. Two eggs sunny-side up: reproductive physiology in the dinosaur Troodon formosus. in Currie, Koppelhus, Shugar and Wright (eds.). Feathered Dragons: Studies on the Transition from Dinosaurs to Birds. Indiana University Press, Bloomington. pp 215-233.
Varricchio and Jackson, 2004. A phylogenetic assessment of prismatic dinosaur eggs from the Cretaceous Two Medicine Formation of Montana. Journal of Vertebrate Paleontology. 24(4), 931-937.
Currie, 2005. Theropods, including birds. in Currie and Koppelhus (eds). Dinosaur Provincial Park, a spectacular ecosystem revealed, Part Two, Flora and Fauna from the park. Indiana University Press. 367-397.
Erickson, Rauhut, Zhou, Turner, Inouye, Hu and Norell, 2009. Was dinosaurian physiology inherited by birds? Reconciling slow growth in Archaeopteryx. PLoS ONE. 4(10), e7390. doi:10.1371/journal.pone.0007390
T. bakkeri (Carpenter, 1982) Olshevsky, 1991
= Pectinodon bakkeri Carpenter, 1982
Late Maastrichtian, Late Cretaceous
Lance Formation, Montana, Wyoming, US
Holotype- (UCM 38445; holotype of Pectinodon bakkeri) tooth (6.2 mm) (Carpenter, 1982)
Paratypes- (UCM 38446) (juvenile) tooth (1.8 mm) (Carpenter, 1982)
(UCM 41666) (juvenile) anterior dentary (Carpenter, 1982)
(UCM 43218) (juvenile) basioccipital (Carpenter, 1982)
(UCM 73098) (juvenile) tooth (2.8 mm) (Carpenter, 1982)
(UCMP 125239) (juvenile) tooth (3.2 mm) (Carpenter, 1982)
(UCMP 125240) tooth (Carpenter, 1982)
(UCMP 125241) tooth (Carpenter, 1982)
(UCMP 125242) tooth (Carpenter, 1982)
(UCMP 125243) tooth (Carpenter, 1982)
(UCMP 125244) tooth (Carpenter, 1982)
(UCMP 125245) tooth (Carpenter, 1982)
(UCMP 125246) tooth (Carpenter, 1982)
(UCMP 125247) tooth (Carpenter, 1982)
Referred- (CMN 30748) partial humerus, ulna, femora, tibia (McIntosh, 1981)
(SDSM 12456) four dentary teeth (Whitmore, 1988)
(SDSM 12458) maxillary tooth (Whitmore, 1988)
(SDSM 15098) three dentary teeth (Whitmore, 1988)
(SDSM 15099) maxillary tooth (Whitmore, 1988)
(UA 156) tooth (Baszio, 1997)
(UA 157) tooth (Baszio, 1997)
(UCMP 84990) tooth (UCMP online)
(UCMP 186864) teeth (UCMP online)
(UCMP 186886) teeth (UCMP online)
(UCMP 186916) tooth (UCMP online)
(UCMP 186979) tooth (UCMP online)
(UCMP 187050-187056) seven teeth (UCMP online)
(UCMP 187058-187079) twenty-two teeth (UCMP online)
(UCMP 187180) tooth (UCMP online)
(UCMP 187181) tooth (UCMP online)
(UCMP 214059) tooth (UCMP online)
(YPM 54491) (YPM online)
(YPM 55041) (YPM online)
(YPM 55521) (YPM online)
(YPM 55536) (YPM online)
(YPM 55545) (YPM online)
(YPM 55546) (YPM online)
(YPM 55583) (YPM online)
(YPM 55584) (YPM online)
(YPM 55591) (YPM online)
(YPM 55592) (YPM online)
(YPM 55627) (YPM online)
teeth (Derstler, 1995)
(juvenile) elements, eggshells (Derstler, 1995)
teeth (Spencer, Turner and Chadwick, 2001)
Comments- Estes (1964) referred teeth to Saurornithoides sp., but these seem to belong to a different species of troodontid (cf. Troodontidae indet. of Sankey et al., 2002). Carpenter (1982) described several teeth as Pectinodon bakkeri, believing them to be distinct from Judith River troodontids, though Currie showed this was due to their position in the jaw (posterior dentary). Virtually no Lance Formation troodontid material has been described except this material, which Currie (1987) felt was indistinguishable from Judith River Troodon, though Currie et al. (1990) stated they were somewhat different. Derstler (1995) considered his juvenile material and eggshells to belong to a new taxon of troodontid. Olshevsky (1991) created the new combination Troodon bakkeri for Lance Formation troodontid teeth, which is used here because the basal tubera are large and the dentary symphysis seems more robust than Zanabazar, though not as much as in T. formosus (due to ontogeny?).
References- Estes, 1964. Fossil vertebrates from the Late Cretaceous Lance Formation, eastern Wyoming. University of California Publications in Geological Sciences. 49, 1-180.
McIntosh, 1981. Annotated catalogue of the dinosaurs (Reptilia, Archosauria) in the Collections of Carnegie Museum of Natural History. Bulletin of the Carnegie Museum of Natural History. 18, 1-67.
Carpenter, 1982. Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod. Contributions to Geology, University of Wyoming. 20(2), 123-134.
Currie, 1987. Bird-like characteristics of the jaws and teeth of troodontid theropods (Dinosauria, Saurischia). Journal of Vertebrate Paleontology. 7, 72-81.
Whitmore, 1988. The vertebrate paleontology of Late Cretaceous (Lancian) localities in the Lance Formation, Northern Niobrara County, Wyoming. Unpublished Masters Thesis. South Dakota School of Mines and Technology, Rapid City, South Dakota. 130pp.
Currie, Rigby and Sloan, 1990. Theropod teeth from the Judith River Formation of southern Alberta, Canada. in Carpenter and Currie (eds.). Dinosaur Systematics: Perspectives and Approaches. Cambridge University Press, New York. pp. 107-125.
Olshevsky, 1991. A Revison of the Parainfraclass Archosauria Cope, 1869, Excluding the Advanced Crocodyila. Mesozoic Menanderings #2 (1st printing). iv + 196pp.
Derstler, 1995. The Dragons’ Grave - an Edmontosaurus bonebed containing theropod egg shells and juveniles, Lance Formation, (Uppermost Cretaceous), Niobrara County, Wyoming: Journal of Vertebrate Paleontology. 15(3), 26A.
Spencer, Turner and Chadwick, 2001. A remarkable vertebrate assemblage from the Lance Formation, Niobrara County, Wyoming. GSA Annual Meeting and Exposition Abstracts. 33(6), A-197.
Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.
T. sp. nov. (Currie, 1987)
Middle Maastrichtian, Late Cretaceous
Horseshoe Canyon Formation, Alberta, Canada
(RTMP 83.12.11) anterior dentary, four teeth (Currie, 1987)
(RTMP 96.29.29) posterior maxillary tooth (Ryan, Currie, Gardner, Vickaryous and Lavigne, 1998)
(RTMP 97.39.3) posterior dentary tooth (Ryan, Currie, Gardner, Vickaryous and Lavigne, 1998)
(RTMP 97.39.5) dentary tooth (Ryan, Currie, Gardner, Vickaryous and Lavigne, 1998)
(RTMP 97.39.7) posterior premaxillary or anterior maxillary tooth (Ryan, Currie, Gardner, Vickaryous and Lavigne, 1998)
(RTMP coll.) six teeth (Baszio, 1997)
(RTMP coll.) nine premaxillary teeth, thirty-nine maxillary teeth, thirteen dentary teeth (Ryan, Currie, Gardner, Vickaryous and Lavigne, 1998)
elements (Ryan and Russell, 2001)
Comments- Currie (1987) described a dentary with teeth that can be referred to Troodon because of its extensive mandibular symphysis. Although Currie et al. (1990) state Horseshoe Canyon Formation teeth are essentially identical to Judith River teeth, Baszio (1997) notes they are are generally smaller than Dinosaur Park (Judith River) T. formosus, but identical in morphology. Ryan et al. (1998) state they could not distinguish Horseshoe Canyon teeth from Judith River teeth, but referred to the former as Troodon sp. due to the stratigraphic difference.
References- Currie, 1987. Bird-like characteristics of the jaws and teeth of troodontid theropods (Dinosauria, Saurischia). Journal of Vertebrate Paleontology. 7, 72-81.
Currie, Rigby and Sloan, 1990. Theropod teeth from the Judith River Formation of southern Alberta, Canada. in Carpenter and Currie (eds.). Dinosaur Systematics: Perspectives and Approaches. Cambridge University Press, New York. pp. 107-125.
Baszio, 1997. Investigations on Canadian dinosaurs: systematic palaeontology of isolated dinosaur teeth from the Latest Cretaceous of south Alberta, Canada. Courier Forschungsinstitut Senckenberg. 196, 33-77.
Ryan, Currie, Gardner and Livigne, 1997. Baby hadrosaurid material associated with an unusually high abundance of troodontid teeth from the Horseshoe Canyon Formation (Early Maastrichtian), Alberta, Canada. Journal of Vertebrate Paleontology. 17(3), 72A.
Ryan, Currie, Gardner, Vickaryous and Lavigne, 1998. Baby hadrosaurid material associated with an unusually high abundance of Troodon teeth from the Horseshoe Canyon Formation, Upper Cretaceous, Alberta, Canada. Gaia. 15, 123-133.
Ryan and Russell, 2001. The dinosaurs of Alberta (exclusive of Aves). in Tanke and Carpenter (eds.). Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie. Indiana University Press, Bloomington, Indiana. pp. 279-297.
Evans, Lam, Maddin and Conacher, 2003. Taphonomy of the Prehistoric Park Quarry, Horseshoe Canyon Formation, Drumheller, Alberta. Alberta Palaeontological Society, Seventh Annual Symposium, "Fossils in Motion" Abstracts. 25-28.
T. sp. nov. (Baszio, 1997)
Late Maastrichtian, Late Cretaceous
Scollard Formation, Alberta, Canada
(RTMP 94.106.1) tooth (Ryan and Russell, 2001)
(UA 109) tooth (Baszio, 1997)
teeth (Ryan and Russell, 2001)
Comments- Baszio (1997) reported UA 109 was similar to Judith River T. formosus in size, but differed in having larger mesial serrations (up to three times wider than distal serrations).
References- Baszio, 1997. Investigations on Canadian dinosaurs: systematic palaeontology of isolated dinosaur teeth from the Latest Cretaceous of south Alberta, Canada. Courier Forschungsinstitut Senckenberg. 196, 33-77.
Ryan and Russell, 2001. The dinosaurs of Alberta (exclusive of Aves). in Tanke and Carpenter (eds.). Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie. Indiana University Press, Bloomington, Indiana. pp. 279-297.
T. sp. (Currie, Rigby and Sloan, 1990)
Campanian, Late Cretaceous
Prince Creek Formation, Alaska, US
Material- (AK83-V-095) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK138-V-128) (subadult) partial braincase (Fiorillo et al., 2009)
(AK233-V-054) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK282-V-001) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK282-V-010) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK282-V-052) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK282-V-056) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK283-V-017) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK283-V-115) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK284-V-024) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK285-V-008) premaxillary tooth (Fiorillo and Gangloff, 2000)
(AK285-V-013) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK285-V-037a) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK299-V-134) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK300-V-017) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK300-V-021) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK300-V-042) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK300-V-055) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK300-V-060) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK300-V-129) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK335-V-012FT) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK335-V-076) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK382-V-015) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK382-V-105) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK383-V-018) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK383-V-137) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK383-V-140) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK383-V-176) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK383-V-183) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK385-V-001) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK385-V-002) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK387-V-000FT) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK387-V-017) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK388-V-002) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK388-V-082) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK392-V-007) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK459-V-011) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK498-V-001) tooth (Fiorillo, 2008)
(AK490-V-004) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK490-V-008FL) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK490-V-086FT) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK491-V-143) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK491-V-168) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK497-V-002) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK498-V-001) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK498-V-002) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK498-V-003) maxillary or dentary tooth (Fiorillo and Gangloff, 2000)
(AK coll.) thirty-three teeth (Fiorillo, 2008)
(DMNH 22158) (adult) partial braincase (Fiorillo et al., 2009)
(UCMP 140624; lost) three teeth (UCMP online)
skull fragments (Gangloff, 1998)
Comments- The two braincases were described as T. formosus, apparently identical to that species except for some pneumatic features, which are known to exhibit marked individual and symmetry variation. These teeth have not been described in detail, though Currie et al. (1990) noted they were somewhat different than Judith River Troodon teeth, and Sankey et al. (2002) said that no examples of their cf. Troodontidae indet. were present in this formation. Fiorillo (2008) found the teeth to be larger on average than T. formosus (9.78 mm in length vs. 4.96 mm), but indentical in length vs. FABL. The Alaskan teeth range from 5.4-14.3 mm in length and 4.3-9 mm in FABL.
References- Currie, Rigby and Sloan, 1990. Theropod teeth from the Judith River Formation of southern Alberta, Canada. in Carpenter and Currie (eds.). Dinosaur Systematics: Perspectives and Approaches. Cambridge University Press, New York. pp. 107-125.
Nelms, 1992. Paleoecological implications of a North Slope Dinosaurian assemblage. International Conference on Arctic Margins, Abstracts. 42.
Gangloff, 1998. Arctic Dinosaurs with Emphasis on the Cretaceous Record of Alaska and the Eurasian-North American Connection. Kirkland, Lucas and Estep (eds). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science, Bulletin. 14, 211-220.
Fiorillo and Gangloff, 2000. Theropod teeth from the Prince Creek Formation (Cretaceous) of Northern Alaska, with speculations on Arctic dinosaur paleoecology. Journal of Vertebrate Paleontology. 20(3), 41A.
Fiorillo and Gangloff, 2000. Theropod teeth from the Prince Creek Formation (Cretaceous) of Northern Alaska, with speculations on Arctic dinosaur paleoecology. Journal of Vertebrate Paleontology. 20(4), 675-682.
Sankey, Brinkman, Guenther and Currie, 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology. 76(4), 751-763.
Fiorillo, 2008. On the occurence of exceptionally large teeth of Troodon (Dinosauria: Saurischia) from the Late Cretaceous of Northern Alaska. Palaios. 23, 322-328.
Fiorillo, Tykoski, Currie, McCarthy and Flaig, 2009. Description of two partial Troodon braincases from the Prince Creek Formation (Upper Cretaceous), North Slope Alaska. Journal of Vertebrate Paleontology. 29(1), 178-187.
T. sp. (Estes, Berberian and Mesozoely, 1969)
Late Maastrichtian, Late Cretaceous
Hell Creek Formation, Montana, South Dakota, US
(MCZ 3694) tooth (Estes, Berberian and Mesozoely, 1969)
(UCMP 186856) tooth (UCMP online)
(UCMP 186868) teeth (UCMP online)
(UCMP 186873) tooth (UCMP online)
(UCMP 186885) teeth (UCMP online)
(UCMP 186904) tooth (UCMP online)
(UCMP 187057) tooth (UCMP online)
(UCMP 187168-187174) seven teeth (UCMP online)
(UCMP 187178) tooth (UCMP online)
(UCMP 187184) tooth (UCMP online)
(UCMP 187186) tooth (UCMP online)
(UCMP 214060-214062) three teeth (UCMP online)
teeth (Stenerson and O'Conner, 1994)
material (Triebold and Russell, 1995; Triebold, 1997)
material (Jacobson and Sroka, 1998)
four teeth (Larson, Nellermoe and Gould, 2003)
Comments- Estes et al. (1969) referred MCZ 3694 to Coeluridae, while Stenerson and O'Conner (1994) called their teeth Saurornithoides sp.. None have been described yet, though the UCMP specimens were identified as Troodon by Sankey.
References- Estes, Berberian and Mesozoely, 1969. Lower vertebrates from the Late Cretaceous Hell Creek Formation, McCone County, Montana. Breviora. 337, 1-33.
Stenerson and O'Conner, 1994. The Late Cretaceous Hell Creek Formation of Northwestern South Dakota and its Fauna. MAPS Digest. 17(4), 108-120.
Triebold and Russell, 1995. A new small dinosaur locality in the Hell Creek Formation: Journal of Vertebrate Paleontology. 15(3), 57A.
Triebold, 1997. The Sandy Site: Small Dinosaurs from the Hell Creek Formation of South Dakota. in Wolberg, Stump and Rosenberg (eds). Dinofest International, Proceedings of a Symposium sponsered by Arizona State University. A Publication of The Academy of Natural Sciences. 245-248.
Jacobson and Sroka, 1998. Preliminary assement of a Hell Creek Dinosaurian Fauna from sites in Corson County, South Dakota. Journal of Vertebrate Paleontology. 18(3), 53A.
Larson, Nellermoe and Gould, 2003. A study of theropod teeth from a low-species-density hadrosaur bone bed in the Lower Hell Creek Formation in Carson, Co., S.D.. Journal of Vertebrate Paleontology. 23(3), 70A-71A.
T. sp. (Langston, 1975)
Maastrichtian, Late Cretaceous
St. Mary River Formation, Alberta, Canada
(CMN 10649) tooth (Langston, 1975)
(CMN 10674) partial tooth (Langston, 1975)
References- Langston, 1975. The ceratopsian dinosaurs and associated lower vertebrates from the St. Mary River Formation (Maestrichtian) at Scabby Butte, Southern Alberta. Canadian Journal of Earth Science. 12, 1576-1608.
Ryan and Russell, 2001. The dinosaurs of Alberta (exclusive of Aves). in Tanke and Carpenter (eds.). Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie. Indiana University Press, Bloomington, Indiana. pp. 279-297.
T. sp. (Ryan and Russell, 2001)
Maastrichtian, Late Cretaceous
Wapiti Formation, Alberta, Canada
(RTMP 89.55.1008) metatarsal (Ryan and Russell, 2001)
teeth (Ryan and Russell, 2001)
Reference- Ryan and Russell, 2001. The dinosaurs of Alberta (exclusive of Aves). in Tanke and Carpenter (eds.). Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie. Indiana University Press, Bloomington, Indiana. pp. 279-297.
T? sp. (Hernandez-Rivera, 1997)
Late Campanian, Late Cretaceous
El Gallo Formation, Mexico
Material- (LACM 42637/HJG 689) tooth (Hilton, 2003)
(42675/HJG 696) tooth (Hilton, 2003)
Comments- These were identified as Saurornithoides by Hilton (2003).
References- Hernandez-Rivera, 1997. Mexican Dinosaurs. in Currie and Padian (eds). Encyclopedia of Dinosaurs. Academic Press. 433-437.
Hilton, 2003. Dinosaurs and other Mesozoic reptiles of California. University of California Press. 318pp.
T? sp. (Williamson, 2001)
Late Campanian, Late Cretaceous
Fruitland and/or Lower Kirtland Formation, New Mexico, US
Material- teeth
Reference- Williamson, 2001. Dinosaurs from microvertebrate sites in the Upper Cretaceous Fruitland and Kirtland Formations, San Juan Basin, New Mexico. 2001 GSA abstracts.
T? sp. (Wroblewski, 1998)
Late Maastrichtian, Late Cretaceous
Ferris Formation, Wyoming, US
Reference- Wroblewski, 1998. Changing paleoenvironments and paleofaunas across the K-T boundary, Ferris Formation, Southcentral Wyoming. Tate Geological Museum, Casper College, Casper Wyoming. Tate ’98. Life in the Cretaceous. 53-70.
T? sp. (Stokosa, 2005)
Maastrichtian, Late Cretaceous
Fox Hills Formation, South Dakota, US
Material- (SDSM 14518) dentary tooth
Comments- This tooth was identified by Stoksad (2005) as Troodon cf. formosus. Its macroscopic structure has not been described.
Reference- Stokosa 2005. Enamel microstructure variation within the Theropoda. in Carpenter (ed). The Carnivorous Dinosaurs. 163-178.
T? sp. (Langston, Standhardt and Stevens, 1989)
Late Maastrichtian, Late Cretaceous
Lower Javelina Formation, Texas, US
Reference- Langston, Standhardt and Stevens, 1989. Fossil vertebrate collecting in the Big Bend - History and retrospective. in Vertebrate Paleontology, Biostratigraphy and Depositional Environments, Latest Cretaceous and Tertiary, Big Bend Area, Texas. Guidebook Field Trip Numbers 1 a, B, and 49th Annual Meeting of the Society of Vertebrate Paleontology, Austin, Texas, 29 October - 1 November 1989. 11-21.
R. sp. (Wel and Williamson, 2000)
Late Maastrichtian, Late Cretaceous
Naashoibito Member of Kirtland Formation, New Mexico, US
Reference- Weil and Williamson, 2000. Diverse Maastrichtian terrestrial vertebrate fauna of the Naashoibito Member, Kirtland Formation (San Juan Basin, New Mexico) confirms “Lancian” faunal heterogeneity in western North America. Geological Society of America Abstracts with Programs. 32, A-498.
Williamson, 2001. Dinosaurs from microvertebrate sites in the Upper Cretaceous Fruitland and Kirtland Formations, San Juan Basin, New Mexico. 2001 GSA abstracts.
T. sp. indet. (Lambe, 1902)
Late Campanian-Maastrichtian, Late Cretaceous
Judith River or Horseshoe Canyon Formation, Alberta, Canada
(RTMP 81.16.321) anterior dentary tooth (6 mm) (Currie, 1987)
(RTMP 81.20.71) anterior premaxillary tooth (Currie, 1987)
(RTMP 82.20.47) posterior dentary tooth (Currie, 1987)
(RTMP 82.20.299) mid-dentary tooth (Currie, 1987)
(RTMP 84.168.5) maxillary tooth (Currie, 1987)
Late Campanian-Maastrichtian, Late Cretaceous
Judith River or Edmonton Group, Alberta, Canada
(CMN 1266) tooth (Lambe, 1902)
(CMN 8841) tooth (Sternberg, 1945)
(CMN coll.) five teeth (Sternberg, 1945)
Late Cretaceous
Alberta, Canada
(RTMP 81.37.15) tenth cervical vertebra (Makovicky, 1995)
(RTMP 92.36.1212) (adult) posterior cervical vertebra (Makovicky, 1995)
(RTMP 94.12.438) third dorsal vertebra (Makovicky, 1995)
Late Cretaceous
US
(AMNH 21629) tooth (AMNH online)
(YPM 55009) (YPM online)
(YPM 55040) (YPM online)
Comments- Though Britt described the posterior cervical vertebrae RTMP 81.37.15 and 92.36.1212 as ornithomimids, Makovicky (1995) indicated they were actually Troodon.
References- Lambe, 1902. New genera and species from the Belly River Series (mid-Cretaceous). Contributions to Canadian Palaeontology, Geological Survey of Canada. 3, 23-81.
Sternberg, 1945. Pachycephalosauridae proposed for domeheaded dinosaurs, Stegoceras lambei n. sp., described. Journal of Paleontology. 19, 534-538.
Currie, 1987. Bird-like characteristics of the jaws and teeth of troodontid theropods (Dinosauria, Saurischia). Journal of Vertebrate Paleontology. 7, 72-81.
Britt, 1993. Pneumatic postcranial bones in dinosaurs and other archosaurs. PhD Thesis, University of Calgary (Canada), Alberta.
Makovicky, 1995. Phylogenetic aspects of the vertebral morphology of Coelurosauria (Dinosauria: Theropoda). M.S. thesis, Univ. Copenhagen, 311pp.