Summary:
- Reptile evolution is currently an area of intense research and constant revision.
- The earliest known reptile, pictured in Figure below, dates back about 315 million years.
- Some of the earliest reptiles to diverge were ancestors of turtles.
- Ancestral crocodilians evolved at least 220 million years ago.
- Tuataras may have diverged from squamates (snakes and lizards) not long after that.
- Finally, lizards and snakes went their separate ways about 150 million Years ago.