RHIPIDISTIA

extinct suborder of lobe-finned bony fishes of the order Crossopterygii, which apparently included the ancestors of amphibians and the other terrestrial vertebrates. The Rhipidistia were common during the Devonian (the Devonian Period lasted from 408 to 360 million years ago) but became extinct during the Early Permian (the Permian Period began 286 million years ago). They were typical crossopterygians; the related coelacanth fishes were a side branch. Anatomical details, including skull-bone patterns, infolded (labyrinthodont) tooth enamel, and elements in the paired fins that correspond somewhat with tetrapod limb bones, support the theory that the rhipidistians gave rise to the land-living vertebrates. Members of the typical genus Osteolepis were sharp-toothed stream and pond dwellers. The related genus Eusthenopteron were slender-bodied predators.