One weird specimen!
This is one of the most extraordinary ammonites. It is clearly an ammonite because the broken edge on the left, next to the label, shows the chamber wall complete with folds that form the suture line. Ammonites from the Lower Chalk did all sorts of strange things, some are partially uncoiled and others became bizarrely decorated with tubercles and spines.
Find out more about ammonites on the molluscs pages.