Herptiles

Herpetozoarios en Español This page is also available in Spanish.

by Arlene, High School for Environmental Studies, NYC

Herptiles are the group of animals that include reptiles and amphibians. Though they may look quite different, amphibians and reptiles are similar in a few ways. This is because reptiles evolved from amphibians.

One similarity is that they are both cold-blooded animals. This means that their body temperature is about the same temperature as their environment. Another similarity is that they are both egg-laying animals.

Amphibians

Amphibians are usually small animals that live in damp environments like swamps frog

and ponds. They go through different stages of development from egg to tadpole and finally, to the adult. This process is called metamorphosis. The egg and tadpole stages require water, while adults may be terrestrial or aquatic.

There are two major types of amphibians: frogs and toads, and salamanders.

Frogs and toads are often confused with each other. Toads usually have shorter legs than frogs. So, where frogs leap, toads simply hop. Also, toads don't live as close to water as most frogs do. Toads have thicker skin than frogs and can live in drier environments.

Salamanders are the second major type of amphibian. They usually have long, lizard-like bodies and most have two or four legs. They are very much like frogs because they spend their lives in the water or wet environments.

To live in water, salamanders need gills. Some salamanders are aquatic and never lose their gills, but some adult salamanders lose their gills and live on land.

Reptiles

Reptiles vary in size from very small to very large, and they have scaly skin. Most reptiles live on land all their lives. Crocodiles, alligators, and some snakes and turtles are the exception.

Reptile development is different than amphibians'. Instead of going through metamorphosis, baby reptiles are miniature versions of their parents when they hatch.

The main categories of reptiles are crocodiles, lizards, snakes, and turtles.

gecko Some examples of lizards are iguanas, geckos, and chameleons. There are many different types of lizards, and their habits and adaptations are just as different.

snake Snakes are legless reptiles that live on the ground, in trees, or in water. They hunt for other animals or eggs, which they swallow whole. To move, many snakes bend themselves from side to side, pushing off rocks or bumps in the ground. To hunt, some snakes are armed with fangs which they sink into their victim and inject a deadly venom. Others slowly suffocate their meal by tightly coiling around it.

turtle The last group of reptiles are turtles. Turtles are the only living reptiles with shells. Most turtle shells are made of an inner layer of bony plates and an outer layer of scales. The bony plates are joined to the skeleton. Turtles don't have teeth, so they use their sharp-edged jaws to tear at the plants and animals they eat.