Wikipedia
The Ichthyostegidae is a small family of extinct labyrinthodont amphibian from the Devonian. All members of the family were relatively large animals with primitively polydactyl, paddle-like feet.
Two genera are assigned to the family: the nominal Ichthyostega from Greenland and Hynerpeton found in Pennsylvania, United States. Both appear to have been fairly capable on dry land, when compared with the contemporary Acanthostegids. Ichthyostega, genus of extinct animals, closely related to tetrapods (four-legged land vertebrates) and found as fossils in rocks in eastern Greenland from the late Devonian Period (about 370 million years ago). Ichthyostega was about one metre (three feet) long and had a small dorsal fin along the margin of its tail; the tail itself possessed a series of bony supports, typical of the tail supports that are found in fishes.