CLADOSELACHE

genus of extinct sharklike fishes of the order Cladoselachii, also known as the order Cladoselachiformes, known from fossilized remains in Late Devonian rocks in North America and Europe (the Late Devonian epoch occurred from 374 to 360 million years ago). Cladoselache was a very primitive form and had many archaic features in the skull and skeleton. Two dorsal fins were present along the midline, and strong spines were developed behind the head and at the base of the pectoral fins. Although Cladoselache was an active predator, the broad attachments of the pectoral fins indicate that only restricted mobility was possible in any direction other than a straight line.