Deinosuchus

Deinosuchus is a giant relative of the alligator that lived in the Late Cretaceous of North America.

Description
Despite its huge size, Deinosuchus was not very different from today's crocodilians. Its teeth were very robust, and the animal's bite force is believed to have equalled or surpassed 18,000 newtons (larger than the bite force of Tyrannosaurus). Deinosuchus had a bony palate which could allow it to breathe when most of its body was underwater, and it large, heavy, deeply pitted scutes.

Size
Because most Deinosuchus fossils are very fragmentary, size estimates vary widely. It was originally believed that it could reach lengths of 15 meters. In 1999, the estimate was reduced to 8 or 10 meters. Later, David Schwimmer compared various skull sizes and concluded that two groups of Deinosuchus existed: a group that lived in the eastern half of the continent and reached 8 meters, and a group that lived in the western half and grew from 10 to 12 meters. These groups comprise two different species in the genus (see Classification, below).

Whatever the correct size, it was still far larger than any modern crocodilian.

Classification
At first, Deinosuchus was believed to be a giant crocodile, but later analysis showed that it was in fact more closely related to alligators. There are two species, D. rugosus and D. riograndensis.

Discovery
Deinosuchus teeth were first found in North Carolina in 1858, although they were believed to come from a genus of pliosaur.

More fossils were found by John Bell Hatcher in Montana in 1903, and they were described in 1909. In 1940, a more complete Deinosuchus was found in Texas. Since then its remains have periodically turned up in seven other states such as Georgia and New Jersey, and a possible specimen has been found in Mexico.

Habitat
Deinosuchus lived on both sides of the Western Interior Seaway, and apparently preferred estuarine environments.

Diet
It was speculated as early as 1954 that Deinosuchus may have preyed upon dinosaurs. Hadrosaurid tail vertebrae discovered in 2002 seem to show tooth marks matching that of Deinosuchus, strongly supporting this theory.