What are Reptiles?
Reptiles are cold-blooded, air-breathing vertebrates which include snakes, lizards, turtles, tortoises, crocodiles, and alligators. Most reptiles hatch from eggs. Both mammals and birds evolved out of reptiles. All three are part of a group called Amniota, which have been the dominant land vertebrates for over 340 million years, since the Carboniferous era. The evolution of the amniote egg was a critical innovation which allowed animals to travel substantial distances from water for the first time in planetary history. In adulthood, reptiles are protected by scales. The first reptile was Hylonomus (“forest mouse”), which lived 315 million years ago in what is now eastern Canada. It was small, about 8 to 12 inches (20 to 30 cm) in length, and consumed insects. Around 230 million years ago, during the Triassic period, new, larger reptiles – the first dinosaurs – evolved, and these would go on to dominate terrestrial ecosystems for 160 million years, until they were wiped out during the C
