The amphibians belong to the class amphibian. Ectothermoc or cold blooded animals like frogs, toads, salamanders, newts, and caecilians metamorphose from a juvenile, water breathing form to an adult, air breathing form. Amphibians are four limbed animals. As by their ancestors "the fish" the amphibians lay eggs in the water. Amphibians are similar to the reptiles.
The ecological indicators (amphibian) around the globe have met a decline in the amphibian population in the recent decades. Since many species are now threatened and extinct the scientists says that it is due to the direct result of the water pollution and other similar sources.
In the Devonian period the amphibians evolved and during the Permian periods they were the top predators in the carboniferous. But in the Permian-Triassic extinction many lineages were wiped out. The metoposaurs the one group of the amphibian existed till the Triassic period but as the world became drier they died early in the Jurassic period. Only the relict temnospondyls like koolasuchus and the modern orders of lissamphibia were left in a handful amount.
Amphibians are the first back bone animals that existed it the earth. They belong to the kingdom animalia and phylum vertebrata. Amphibians are further classified into three orders. To know more about it click here Classification of Amphibians
Amphibians are cold blooded animals that posses backbone and are the direct offspring of fishes. They have the capacity to live both on land as well as in water. Amphibians have complex circulatory system unlike fish that have scales. The larvae of the amphibians that develop in the water breathe through gills while the adults breathe through skins and lungs. Some amphibians are terrestrial at some point of time in their life cycle.
To study more about the distinct features of the amphibians that display the features between the fish and reptiles visit the page Characteristic of Amphibians.