Belemnites died out at the same time as ammonites and dinosaurs.
Belemnites are an extinct group of cephalopod that probably looked like a squid.
Unlike nautiloids and ammonites, belemnites had a very solid internal skeleton called a rostrum. Many people will be familiar with belemnite rostra, they are straight, and look rather like bullets.
Apart from their shells, palaeontologists have also found some belemnite fossils that show their internal structure and soft parts. These fossils tell us a great deal about the way these animals lived. Belemnites had large eyes, and swam quickly using a form of jet propulsion. Like the octopus they could probably squirt clouds of black ink at their enemies to avoid attack.
Belemnite shells (rostra) are common fossils in some parts of Britain.
Belemnites first appeared about 360 million years ago. Along with ammonites and dinosaurs, they died out at the end of the Cretaceous period 65 million years ago.
The molluscs are split into different groups - the gastropods, bivalves and cephalopods. The cephalopods are also split into three groups.
If you read these pages you should become an expert invertebrate identifier!
The major groups are listed below - select a link to learn more about this type of fossil.
Echinoderms Return to the wheel
If you know it all already, return to the Homepage or test yourself with our Quiz!