Agatized Belemnite Fossil Polished (6-7cm)

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.

Belemnites lived during the periods of Earth history known as the Jurassic and Cretaceous; together, these represent a time interval of about 135 million years. The Jurassic Period began about 201 million years ago and the Cretaceous Period ended about 66 million years ago.

The belemnites became extinct at the end of the Cretaceous Period, at roughly the same time as the dinosaurs disappeared. However, we know a lot about them because they are commonly found as fossils, formed when the remains of traces of the animal became buried by sediments that later solidified into rock.

Belemnites were marine animals belonging to the phylum Mollusca and the class Cephalopoda. Their closest living relatives are squid and cuttlefish.They had a squid-like body but, unlike modern squid, they had a hard internal skeleton.