Belemnite Anatomy Revealed

Belemnites were ancient marine cephalopods that lived during the Mesozoic Era. These creatures had a cone-shaped internal shell called a guard, which was made of calcite and provided buoyancy. The guard was divided into chambers, with a small chamber at the pointed end and a larger chamber at the wide end. Belemnites also had a long, straight shell called a phragmocone, which housed the animal’s soft body, including tentacles, eyes, and a beak.