Rhipidistia (class Osteichthyes, subclass Crossopterygii) A group of ‘tasselfinned’ fish that lived from the Devonian to the Permian Periods. They possessed two dorsal fins, lobate or stalked pectoral and pelvic fins, a heterocercal or diphycercal tail fin, and internal nares. Distantly related to the living coelacanth, they are considered by some to be ancestral to the tetrapod, terrestrial vertebrates (i.e. Amphibia).

Rhipidistia Group of crossopterygian (‘tassel-finned’) fish ranging from the Devonian to the Permian. They possessed two dorsal fins, lobate or stalked pectoral and pelvic fins, and internal nostrils. Distantly related to the living coelacanth, they are considered by some to be ancestral to the Tetrapoda (terrestrial vertebrates).