Permian reptiles

With the close of the Carboniferous, reptiles became the dominant tetrapod fauna. While the terrestrial reptilomorph labyrinthodonts still existed, the mammal-like reptiles evolved the first terrestrial megafauna in the form of pelycosaurs like Edaphosaurus and the carnivorous Dimetrodon. In the mid-Permian the climate turned dryer, resulting in a faunal turnover. The primitive pelycosaurs where replaced by the more advanced therapsids.

The anapsid reptiles, with their massive skulls without postorbital holes, continued and flourished throughout the Permian. The pareiasaurs reached giant proportions in the late Permian, eventually disappearing at the close of the period (the turtles being possible survivors).

Early in the period, the diapside reptiles split into two lineages, the lepidosaurs (forefathers of modern snakes, lizards, and tuataras). The group remained lizard-like and relatively small and inconspicuous during the whole periode.