Mr Wood 's Fossils - mwfossils@blueyonder.co.uk

Nautiloids belong to a group of animals called Cephalopods, a group including fossil Ammonites and modern Octopuses, Squid and the pearly Nautilus.

Nautiloids have an external shell divided into chambers by walls known as septa. Contact between septa and the shell wall produces suture lines, often visible in fossil remains.

The animal itself lived in the last formed chamber of the shell. It's head protruded through the opening and had eyes and a simple jaw, surrounded by tentacles.

The oldest Nautiloids had straight shells and are known as orthocone these first lived about 500 million years ago. Later partly coiled and coiled shells developed.