Cheiracanthus (from Greek: χείρ kheír, 'hand' and Greek: ἄκανθα akantha, 'spine')[1] is an extinct genus of a group of fish called Acanthodii (or "spiny sharks").[2] It was a deep-bodied acanthodian about 12 in. (30 cm) in length. It had a blunt head, upturned tail, and fins protected by spines. Unlike many other acanthodians, it had one, solitary dorsal fin. Cheiracanthus swam at mid-depth in lakes and rivers, seizing small prey in its gaping jaws. Whole fossils of this fish occur only in Mid-Devonian rocks in Scotland, but its distinctive small, ornamented scales crop up around the world, as far south as Antarctica.
| Cheiracanthus Temporal range: Middle Devonian | |
|---|---|
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| Fossil of Cheiracanthus latus at the London Natural History Museum | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | †Acanthodii |
| Order: | †Acanthodiformes |
| Family: | †Cheiracanthidae |
| Genus: | †Cheiracanthus Agassiz, 1835 |
| Type species | |
| † Cheiracanthus murchisoni | |
