Phytosaur
Late Triassic (Norian)
Upper Redonda Formation, Chinle Group
Quay County, New Mexico, USA

19mm tooth on 58mm matrix.

Phytosaurs (Order Phytosauria) were crocodile-like archosaurs that lived during the Late Triassic of various parts of North America.  Some species were larger than any crocodile living today, exceeding 25 feet in length.  The group died out during the end-Triassic mass extinction.

One way phytosaurs differed from crocodilians was in their teeth.  Phytosaurs had long, conical teeth in the front of their jaws (anteriors) and spade-shaped, serrated-edge teeth in the back.  As a rule, crocodilians have had back teeth that are also conical but shorter.