The Geology of Delaware

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Vertebrates: Phylum Chordata

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Phylum Chordata includes the vertebrates. Although not as common as the invertebrates, teeth and bones from different classes of vertebrate animals can be found at Canal sites.

Chondrichthyes, or “cartilage fish,” include the sharks, skates, and rays. Teeth and vertebrae from these animals are the most common types of vertebrate fossil found. They may be found on the surface of a rock outcrop or in various spoil piles.

The most commonly found shark teeth belong to the extinct shark Squalicorax. These broad and serrated teeth are easy to identify to the genus level, but it is more difficult to distinguish between the species. Teeth of the goblin shark, Scapanorhynchus, are the largest shark teeth found at the Canal, with some specimens reaching over two inches in length. The teeth of this shark have caused workers much confusion because teeth from different parts of the mouth have different and distinct shapes. At one time there were three different names given to the teeth of this single shark species.

Osteichthyes, or “bony fish,” are represented by the dagger-like teeth of the Cretaceous predator Enchodus. Single, isolated teeth and small sections of the jaw with teeth still attached are relatively common finds. Teeth from other bony fish include Anomoeodus and Stephanodus. Vertebral columns of bony as well as cartilaginous fish are also found on the spoil piles.

Reptile remains are rare and thus the most treasured finds from the Delaware Cretaceous. Teeth of the sea-going reptile Mosasaurus and fragments from the upper and lover shells of turtles are the usual finds. Most collectors have to hunt for years before they find a single mosasaur tooth.

Reference(s): 

Unless otherwise noted, photographs and figures are from DGS Special Publication No. 18, by E. M. Lauginiger, 1988.

Photo Gallery
8. Batoid vertebra - specimen from the Marshalltown Formation, also occurs in the Mount Laurel Formation and the Merchantville Formation<br>9. Shark vertebra - specimen from the Merchantville Formation, also occurs in the Mount Laurel Formation and the Marshalltown Formation<br>
1, 2, 3. Scapanorhynchus texanus - specimens from the Marshalltown Formation, also occur in the Merchantville Formation<br>4. Squalicorax kaupi - specimen from the Marshalltown Formation, also occurs in the Mount Laurel Formation and the Merchantville Formation<br>5,6. Squalicorax pristodontus - specimens from the Marshalltown Formation<br>7, 8. Odontaspis sp. - specimens from the Marshalltown Formation, also occur in the Mount Laurel Formation and the Merchantville Formation<br>Plus More
Shark's tooth<br>Cretaceous Chordata illustration from Page 15, DGS Special Publication No. 9, 1992.
Squalicorax kaupi - occurs in the Mount Laurel Formation, the Marshalltown Formation, and the Merchantville Formation<br>Shark vertebrae - occurs in the Mount Laurel Formation, the Marshalltown Formation, and the Merchantville Formation<br>Scapanorhynchus texanus - occurs in the Marshalltown Formation and the Merchantville Formation<br>Odontaspis sp. - occurs in the Mount Laurel Formation, the Marshalltown Formation, and the Merchantville Formation<br>Plus More
4. Anomoeodus phaseolus - complete lower jaw section of a bony fish - specimen from the Marshalltown Formation, also occurs in the Mount Laurel Formation and the Merchantville Formation<br>5. Enchodus ferox - side view of an isolated tooth - specimen from the Mount Laurel Formation, also occurs in the Marshalltown Formation and the Merchantville Formation<br>Plus More
1. Turtle shell fragment from the plaston - specimen from the Merchantville Formation, also occurs in the Marshalltown Formation<br>2. Trionyx sp. - middle scute from the carapace of a soft shelled turtle - specimen from the Merchantville Formation<br>Plus More