#cheiracanthus

[pixeldinos]

Ancient spiny Scottish “shark” 01/09/2016 Cheiracanthus murchisoni When: Middle Devonian Where: Freshwater lakes and rivers in what is now Scotland Size: About 5 cms Fun Fact: The group of organisms that this fish belonged to, the acanthodians “shiny sharks” were one of the first few vertebrates to use hinged lower jaws, this made them efficient predators, despite their tine size. (They aren’t really sharks, they preceded sharks by 50 million years.)

[palaeopedia]

The hand spine, Cheiracanthus (1843)

Phylum : Chordata Class : Acanthodii Genus Cheiracanthus Species : C. murchisoni

Middle Devonian (400 Ma)

30 cm long (size)

Scotland (map)

Cheiracanthus is an extinct genus of a group of fish called Acanthodii (or "spiny sharks"). It was a deep-bodied acanthodian about 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.