Kingdom: Animalia
Phylum: Chordata
Class: Reptilia (Reptiles)

Reptile species can be found in all types of habitat except polar ice and tundra. Most are terrestrial but some also spend a great deal of time in the water. All reptiles are vertebrates, meaning they have a backbone or spine, they are covered with scales and have lungs for breathing. Reptiles are ectothermic, also known as cold-blooded, so they're unable to control their own body heat and must obtain warmth from sunlight and the environment around them. If they get too hot, they have to find shade or a burrow to help them cool down. Reticulated pythons and saltwater crocodiles are the largest living reptiles and may grow to more than 7 metres in length, the smallest are dwarf geckos which only grow to about 20mm in length.