Amphibians are the eldest of the class tetrapod vertebrates and are supposable descendent from teleost fishes which reached at first terra forma in the upper Devonian era.

The larvae of the amphibians inhabit water and ripen until they experience a metamorphosis and are henceforth able to live on terra forma. Still they are dependent on proximity of water lifelong and are mostly nocturnal to keep the moisture loss as low as possible.

Recent representatives are batrachians, salamander and caecilian.