Reptiles found in the world belong to vertebrate animal classification. The bodies of the reptiles are covered with dry, horny scales and plates. They have their habitat very close to the ground. Reptiles are skilled to live on both land and in water. The structure of the reptile body has been designed to make it comfortable in both habitats. Except snake most of the reptiles have four limbs. Since reptiles are classified into four main groups and each group have their own characteristic it is easy and useful to study the anatomy of each group separately.