Reptiles, a diverse team of air-respiratory vertebrates, are characterised by their scaly pores and skin, amniotic eggs, and ectothermic (cold-blooded) metabolism. They are really traditionally classified into 4 living orders: Crocodilia (crocodiles and alligators), Sphenodontia (tuataras), Squamata (lizards get more info and snakes), and Testudine