Uatchitodon

Uatchitodon is an extinct genus of Late Triassic reptile known only from isolated teeth. Based on the structure of the teeth, Uatchitodon was probably a carnivorous archosauromorph. Folded grooves on the teeth indicate that the animal was likely venomous, with the grooves being channels for salivary venom. The teeth are similar to those of living venomous squamates such as Heloderma and venomous snakes. Uatchitodon and Microzemiotes are the earliest known potentially venomous reptiles.

==Description and species== The genus was first named with the description of the type species U. kroehleri by Hans-Dieter Sues in the journal Nature in 1991. U. kroehleri is known from several teeth found from the early middle Carnian Turkey Branch Formation of the Newark Supergroup in Virginia, uncovered from the Tomahawk locality. The teeth average around 10 mm in length. The tooth crown is strongly labiolingually compressed, recurved, and serrated along both the anterior and posterior edges. The serrations are formed from individual denticles, each of which is further denticulated. On both the labial (outer) and lingual (inner) surfaces of the tooth, there is a deep central groove running longitudinally. The grooves form deep invaginations that constrict the inner pulp cavity of the tooth. The grooves do not reach the tip of the tooth.