Although the earliest temnospondyls were primarily semiaquatic , they had the ability to feed on land . Later , eryopoids and dissorophoids , some well adapted to terrestrial life , also fed on land . Some eryopoids became better adapted toward life in water , and shifted their diets toward aquatic organisms . The first primarily aquatic feeders were archegosaurs in the Permian . Trematosaurs and capitosaurs became independently aquatic and also returned to this type of feeding .