Ammonites and Belemnites were two types of extinct cephalopod molluscs. Ammonites existed from the Devonian period to the end of the Cretaceous period, as evidenced by their fossilized shells found in limestone and chalk. Their shells had a pattern of grooves called sutures that strengthened the shell. Belemnites, which existed until the end of the Cretaceous period, are represented by fossilized guards known as rostra that protected their lower mantles. Clusters of belemnite guards resemble lightning strikes embedded in rock.

1. Ammonites and Belemnites

3. 2. The Fossilization cycle

4. 3. Cephalopod Class

6. Belemnites

8. References http://www.paleodirect.com The Encyclopaedia of Palaeontology Rhodes Whitmore Fairbridge, David Jablonski 1979 Page 72 Photography and Identification.