The dentition of the Neotropical lizard genus Teius Merrem 1820 (Squamata Teiidae)

Within the genera of the Neotropical family Teiidae, Teius Merrem 1820 and Dicrodon Dumeril & Bibron 1839 have been joined by the presence of transversely expanded posterior teeth. However, the particularities of the dentition of Teius have only been tangentially described by several authors and the complex nomenclatural history of the genus has complicated comparisons of the three currently recognized species. In this paper, we describe in detail the dentition of the genus and compare it among species. The dentition of Teius is characterized by the following: (1) the implantation is subpleurodont, with abundant cement deposits totally filling the dental gutter; (2) marginal dentition is heterodont, with unicuspid anterior teeth and multicuspid posterior teeth; (3) six tooth morphologies are recognized, including two types of unicuspid teeth and two types of both bicuspid and tricuspid teeth (with longitudinally and transversely aligned cusps); (4) the transversely bi- and tricuspid teeth are positioned posterior to the longitudinally bi- and tricuspid teeth respectively, and they presumably originate from migration of the cusps; (5) tooth count is higher in the dentaries than in the maxillae in each species, and in both the maxillae and dentaries of the largest species (T. teyou); (6) pterygoid teeth are present in all species, but in higher number in T. teyou (Daudin 1802); (7) tooth replacement is continuous along all the dental series, and replacement pits are variably found on functional tooth sockets; (8) occlusion of the posterior teeth is interdigitated.