Scientist classifies the reptiles present in the world into four main groups known as orders. The four groups are as follows:
The large reptiles such as crocodiles, alligators, caimans and gavials belong to the order Crocodilia. The reptiles in the crocodilia are carnivorous and are mostly found in tropical and subtropical swaps and rivers. This order is the subclass of Archosauria (ruling reptile). Dinosaurs the extinct reptile belong to this order.
The terrestrial reptiles such as lizards and snakes belong to Squamata order. The members of this species have the ability to creep with the help of their abdomen.
The turtle and tortoise creatures belong to the Testudines order. These species have bony shell with horny plates for their protection. These are mostly aquatic and are the oldest living reptile in the world.
Sphenodonita order composes of a single member called Tuatara. It is lizard like reptile found in the lands of New Zealand.