What is a Reptile?

Reptiles are air-breathing, vertebrate animals that have skin with scales, or scutes. They generally lay tough, leathery shelled eggs and they inhabit every continent on Earth except Antarctica. Reptiles are ectotherms, controlling their body temperature by external means.

Although most reptiles are oviparous, or egg-laying, some are ovoviviparous (eggs develop inside the mother’s body), and some are viviparous, giving birth to live young without the development of eggs.

The science of herpetology is the study of reptiles. Four living orders of reptiles are recognized:

  • Squamata: lizards and snakes – approximately 7900 species worldwide
  • Crocodilia: crocodiles, alligators, gavials, and caimans – 23 species
  • Testudines: turtles and tortoises – approximately 300 species
  • Sphenodontia: tuataras from New Zealand – 2 species

Reptiles range in size from the tiniest gecko at ½ inch in length to the Saltwater crocodile that can weigh over 2000 pounds and can reach 18 feet long. Many species of reptiles are listed as threatened or endangered primarily due to human encroachment and habitat loss.