The Field Centre at Monkton Nature Reserve has an extensive geological collection. including many rare items.

Perhaps the most unusual and unique is the complete lower jaw palette of extinct cretaceous (65 – 142 million years ago) shark Ptychodus polygyrus found by Mr George Slade of Ramsgate. It is thought that this is the only complete specimen of its kind in the world

An article about the discovery of the jaw palette can be downloaded from our articles page.

There is still some discussion among palaeontologists as to whether the Ptychodus shark species are actually more closely related to rays, but it is agreed that the shape of the teeth and jaws indicate that it probably used them to crush and feed on shellfish.

Links:
Cretaceous Palaeontology of Kansas