OSTEOLEPIS

extinct genus of lobe-finned fish generally regarded as very primitive, although it survived into later Devonian time (the Devonian Period lasted from 408 to 360 million years ago) and was contemporaneous with more advanced relatives. Its body was covered with large rhomboid scales; the upper lobe of the tail was more strongly developed than the lower lobe. An advanced trait of Osteolepis is the general bone pattern in the skull and jaws, a pattern ancestral to that of early amphibians.