10" Plate of Jurassic Belemnites (Youngibelus) - Posidonia Shale

Belemnites are probably the most well known extinct cephalopod after the ammonites. They lived during the Jurassic and Cretaceous periods and are fairly common fossils found throughout the world. They had a hard, internal, cone-shaped structure that is often preserved as a fossil, though it is not technically a shell. They had ten arms but, unlike modern squid, these arms had small hooks instead of suckers.