Dinosaurs of South Jersey

While all of us are familiar with the dinosaur discoveries of the western US, many don't realize that dinosaurs have been found on the east coast. In fact, many of the early discoveries occurred in New Jersey.

By far the most famous of these discoveries was that of Hadrosaurus foulkii. It was discovered in 1838 by workers digging a marl pit on a farm in Haddonfield, NJ . It wasn't until 1858 that it came to the attention of science. William Foulke was vacationing in Haddonfield when he heard of some large bones found in a pit on the farm of John Hopkins. Foulke, a member of the Philadelphia Academy of Natural Science, organized an expedition to relocate the site. After considerable searching, an excavation revealed a mass of large dark-colored of bones. Dr Joseph Leidy, also of the Academy, was brought in to study the find.

The discovery was significant, not only because it was the first dinosaur skeleton found in the Western hemisphere, but was in fact the first nearly complete dinosaur found in the world. It also dramatically changed how dinosaurs were viewed. Before its discovery, dinosaurs were assumed to be low, squat, lizard-like quadrupeds. But as Leidy pointed out, the small forelimbs and large rear leg bones were clearly those of a biped.

The Hadrosaur also set another precedent by being the first dinosaur skeleton to be mounted. It was put on display in the Philadelphia Academy of Science in 1868, and gave the public their first glimpse of these massive creatures.

Interestingly, although the Hadrosaur was a very early dinosaur find, it was not the first in New Jersey. Benjamin Franklin lectured in the American Philosophical Society in Philadelphia on the discovery of a large leg bone found in the banks of Woodbury Creek. This find predates by a number of years the early discoveries of dinosaurs in England. This specimen was apparently lost for many years, but a bone matching the description was located recently.

The city of Philadelphia was a major academic center of America for much of the 19th century. Many prominent scientists studied the fossils continually being discovered from greensand marl pits across the river. One of the most famous of these was Edward Cope. A student of Leidy in Philadelphia, he became one of the most prominent paleontologists ever.

In 1863, Cope moved from Philadelphia to Haddonfield, NJ. He lived in the center of town, where the borough hall of Haddonfield now stands. There he was able to study the fossils from the local marl pits, where he made contacts with the marl workers to send him their finds. His life was marked by the fierce rivalry he shared with Othniel Marsh. The 'bone wars' they waged in Wyoming and Colorado are legendary, but their relationship was at first friendly, as Cope shared some of his more prolific localities on a visit by Marsh. The relationship soured, however, when Marsh paid marl workers to send fossils his way, rather than to Cope.

Perhaps the most spectacular discovery of Cope during his stay in New Jersey was that of a partial skeleton of a carnivorous dinosaur, Laelaps, in a marl pit near Barnsboro, Gloucestor County. Now known as Dryptosaurus, it represented one of the earliest theropods found. Its most distinguishing feature was the presence of dagger-like nine inch claws on its forelimbs.

Another unique find was the discovery, in 1929, of the footprints of a large carnivorous dinosaur at Woodbridge, NJ. This represents the only Cretaceous dinosaur footprints east of the Mississippi. The clay was still soft, making removal of the footprints nearly impossible. A single footprint remains, displayed in the Geological Museum of Rutgers.

Unfortunately, the decline of the marl industry has reduced the number of localities where dinosaur fossils may be found. The last functioning pit is the Inversand Pit at Sewell, Gloucestor County. A partial skeleton of Hadrosaurus minor, and a number of isolated bones have been found there over the years, including those of a Dryptosaur.

A thin scattering of dinosaur remains have been found in South Jersey, though they are generally extremely rare. This is for three major reasons. First, during most of the Cretaceous New Jersey was under water. Thus, the bones had to survive washing down streams and rivers into the ocean to become fossilized. The Hadrosaurus foulkii find was especially unlikely, since the entire carcass had to float out to sea and become buried before it was torn apart by scavengers. The second reason dinosaur finds are rare is the lack of exposure of dinosaur age outcrops. A narrow band of Cretaceous formations extends northeast from Salem County to Sandy Hook. Unfortunately, this band is covered nearly everywhere by a thick deposit of Tertiary and recent deposits. Generally, only deep streams expose the Cretaceous sediments. Dinosaur footprints of Triassic and Jurassic age are found in north Jersey, however, these rocks are not exposed further south. Finally, numerous housing developments have obscured many once prolific sites.

Despite these drawbacks, a number of interesting finds have been made in recent years, largely through the efforts of dedicated amateur collectors. In 1980, two amateurs, Bob Denton and Bob O'Neal discovered a number of bone fragments near Ellisdale, Burlington County. An excavation of the site was done by the New Jersey State Museum. Bones and teeth of Hadrosaurus and Dryptosaurus were found, along with extremely rare mammal and amphibian remains. Another site where dinosaur remains are still being found is Big Brook, in Marlboro, Monmouth County. This site is one of the more accessible and prolific fossils sites in the area. However, the odds of finding any dinosaur remains in south Jersey are still remote. The author considers himself very lucky to have several Hadrosaur teeth and some probable dinosaur bone fragments. Generally, the collector is looking for other fossils, such as shark teeth or molluscs, and stumbles on dinosaur remains by chance.

The number of species which have been positively identified in New Jersey are small, at least partly because the finds are almost always fragmentary. The currently accepted species include: Hadrosaurus foulkii; Dryptosaurus aquilunguis; Lambeosaurinae indet.; Hadrosaur minor; Nodosauridae indet.; Ornithomimus. Gallagher (1993) Other specimens hint at further types, and are awaiting further study.

Besides their remains, research has also been conducted on the possible causes of the great extinction which wiped out all the dinosaurs and many other forms of life. Southern New Jersey has exposures of the interval during the extinction. Known as the K/T boundary, this zone separates the Age of Dinosaurs from the Age of Mammals which followed. According to current theories, an asteroid hit the Earth about 65 million years ago, causing a cloud of ash and smoke to blot out the sun and resulting in the death of many plants and the animals, both on land and in the sea.

Although many exciting discoveries of dinosaurs and the animals which lived with them in New Jersey have been made over the years, much more remains to be found. Careful collection by both amateurs and professionals will insure our increasing knowledge of the life of the dinosaurs.


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Steve Kurth