Cheiracanthus

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Cheiracanthus is an extinct genus of early fishes known as acanthodians, often called spiny sharks. The name comes from Greek words meaning “hand” and “spine.”

It lived in the Middle Devonian period and was about 30 cm long. Cheiracanthus had a deep body, a blunt head, an upturned tail, and fins protected by spines. Unlike many other acanthodians, it had only one dorsal fin. It swam in mid‑depth waters of lakes and rivers, catching small prey with its wide mouth.

Fossils of Cheiracanthus are mainly found in Scotland, but its distinctive small, ornamented scales are found in other parts of the world as well, reaching as far south as Antarctica. The type species is Cheiracanthus murchisoni.