Reptiles (along with amphibians, mammals, birds and fish) are vertebrate animals. This means they have an internal skeleton (made of bone or cartilage) and a backbonewhich is also called a vertebral column.
Reptiles include snakes, lizards and turtles and they are all characterised by having an external covering of scales or horny plates and by breathing through lungs. All reptiles are ‘tetrapods’ which means they have four legs. Snakes are also tetrapods even though they have no legs now. Their legs have been lost over the many years of evolution.
With the exception of the Leatherback Turtle our native reptiles, like most reptiles, are cold-blooded and they derive virtually all of their heat from sources outside of their body. Heat is generated by sunlight or by lying on warm rocks. The study of reptiles (or amphibians) is called herpetology and the latin term ‘reptilia’ means creeping animals.