Paleozoic era → Amphibian (395 MA)

Amphibians were the first group of vertebrates to develop limbs and to be able to leave the water to conquer the land. Even if they are seen as simple and primitive animals by most people, amphibians show a wide diversity of survival strategies which have allowed them to occupy most terrestrial and fresh-water habitats.

Amphibians are animals that live part of their lives in water and part on land.  They usually have soft, moist skin that is protected by a slippery layer of mucus. They also tend to live in moist places or near water to keep their bodies from drying out. There are different groups of amphibians: caecilians; salamanders, newts, and mudpuppies; and frogs and toads.

All amphibians:

• Are vertebrates (which means they have a backbone or spine).

• Are ectothermic. Also known as “cold-blooded,” ectothermic animals cannot regulate their own body heat, so they depend on warmth from sunlight to become warm and active. If they get too hot, they have to find shade or a burrow to help them cool down.

• Breathe through their skin.

• Go through metamorphosis. Young amphibians hatch from eggs, but do not look like their parents. As they develop, their body shape changes.