Reptiles First truly terrestrial vertebrates ~7000 species worldwide ~300 species in U.S. and Canada. Reptiles Probably best remembered for what they once were, rather than what they are now Mesozoic era - age of reptiles Dominant group for150 millions years
Reptiles 12 or so principal groups of reptiles evolved Only 4 groups remain today. Order Squamata Snakes and lizards 5800 species Most successful group. Order Crocodilian Crocodiles, alligators, caiman ~25 species. Have survived for 200 million years