Fossils have been found on every continent. Their evolutionary history spans 210 million years. During this time, they adapted to a wide range of habitats including fresh water, terrestrial, and even coastalmarineenvironments. Fossils are known from the larval stage, metamorphosis, and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted to life on land. Although temnospondyls are considered amphibians, many had characteristics such as scales, claws, and armour-like bony plates which modern amphibians do not have.