Reptiles, a diverse group of air-respiratory vertebrates, are characterized by their scaly pores and skin, amniotic eggs, and ectothermic (chilly-blooded) metabolism. They are ordinarily labeled into 4 dwelling orders: Crocodilia (crocodiles and alligators), Sphenodontia (tuataras), Squamata (lizards and snakes), and Testudines (turtles and tortois