Early Nautiloid Shell Fossils

Nautiloids are primitive marine cephalopods that possessed a shell. They were most abundant during the Palaeozoic Era, some 400 million years ago. The shell is divided into body chambers. Some Nautiloids evolved into Ammonoids. Today, only a single genus survives - the pearly nautilus of the south west Pacific Ocean and much of what we know derives from its species. Nautiloids have heads with well developed eyes and grasping tentacles. They swim by squirting water out from the body cavity.

The Nautiloid Cephalopods are the group of Cephalopods that have a simple suture pattern to the shell. The suture is either gently curved or nearly straight.

Chambered Nautilus

The Chambered Nautilus is a living species of the Nautiloid Cephalopods. The shell of the Nautilus is subdivided into various rooms which are connected by a tube called the siphuncle. They are able to use the shell as a buoyancy compensation device. They can fill the rooms (camera) with water, air, or possibly sediment to balance their body in the water. This makes the Cephalopod an excellent predator.