Three different ammonites?
There appear to be three different kinds of ammonites in this rock, as well as a piece of fossilised wood. The larger ammonites are Xipheroceras, while the one lying against the wood is Promicroceras. But these two different ammonites are now thought to be the same genus and species – some people think that the larger Xipheroceras is the female, while the smaller Promicroceras is the male. The tiny ammonites are Cymbites.
Find out more about ammonites on the molluscs pages.