Bargain, 6.3" Fossil Shark (Asteracanthus) Dorsal Spine - Morocco

Bargain, Fossil Shark (Asteracanthus) Dorsal Spine - Morocco #49546

This is a 6.3" fossil, dorsal spine of a Cretaceous shark (Asteracanthus) from the Kem Kem Basin, Taouz, Morocco. This specimen shows lateral ridges and denticles along posterior edge. Spines of Asteracanthus are much rarer than the spines of Hybodus found in the same formation.

The spine has quite a few repaired cracks and some restoration on one side.

Hybodus was a small shark that grew up to 2 meters in length and was likely an opportunistic predator. It had a streamlined shape ideal for hunting down fast prey and two different types of teeth: sharp cutting teeth for catching prey and flatter grinding teeth for crushing. This combination may have been the key to Hybodus' success.

A paper on Hybodus spines can be found below.

Growth And Form of Finspines In Hybodont Sharks

A complete fossil of Hybodus from Germany showing placement of spine. Image under GNU Free Documentation License