lobefin

lobefin common name for any of a group of lunged, fleshy-finned, bony fishes , also called crossopterygians, that were dominant in the Devonian period and gave rise to amphibians . They had heavy, ungainly bodies and stumpy paired fins, the precursors of the limbs of four-footed animals. Known from their fossils, the lobefins were thought to be extinct until 1938, when a live coelacanth was caught in deep water off S Africa. Since then other specimens have been discovered in the Madagascar area. The coelacanths are a marine branch of the lobefins. The coelacanth discovered in 1938, Latimeria chalumne, is a brown to steel-blue fish 5 ft (150 cm) long, with circular, overlapping scales, a laterally flattened three-lobed tail, a spiny dorsal fin, and a vestigial lung. The fish give birth to live young. The coelacanth is the nearest living fish relative of the amphibians. In 1998 a closely related coelacanth, L. menadoensis, was discovered in Indonesia. Lobefins are classified in the phylum Chordata , subphylum Vertebrata, class Osteichthyes, order Crossopterygii. See lungfish .

Bibliography: See S. Weinberg, A Fish Caught in Time (2000).