Anapsid

The anapsids are a group of amniotes, characterized by skulls without openings near the temples. The only extant members are the Testudines - turtles, tortoises, and terrapins. Various other groups, however, are known from Permian and Triassic fossils. The anapsids have traditionally been treated as a subclass of the class Reptilia, but as this group is paraphyletic they are sometimes placed in a separate class Anapsida.

Most of the anapsid orders, including groups the, millerettids[?], nyctiphrurets[?] and pareiasaurs[?], were extincted in the late Permian period by the Permian-Triassic extinction event. Both the procolophonoids[?] and some ancient ancestors of the testudines managed to survive into the Triassic, and the testidunes are the only surviving order.

External links

Introduction to Anapsida (http://www.ucmp.berkeley.edu/anapsids/anapsida.html) from UCMP