genus of extinct sharks, known from fossilized remains in Late Devonian rocks in North America and Europe (the Late Devonian epoch occurred from 385 million to 359 million years ago).

Cladoselache is a good representative of early sharks. Unlike larger forms, its mouth opened at the front of the skull, rather than beneath it, and both its pectoral and pelvic fins were broadly attached to its body. These features suggest that while this shark was less maneuverable than larger sharks, it was a high-speed predator. Two dorsal fins were present along the midline, and strong spines were developed behind the head and at the base of the pectoral fins.