AGE: Lower Jurassic, 180 million years old
This ammonite is from the Junction Bed which is known as a ‘condensed sequence’ because the sediments formed slowly and at times were even eroded away. As a result, the fossils tend to be quite poorly-preserved but they remain identifiable. This ammonite is Hildoceras bifrons, the classic ammonite known from Whitby, and named after St Hilda.

Ammonites were predatory mollusks that resembled a squid with a shell. These cephalopods had eyes, tentacles, and spiral shells. They are more closely related to a living octopus, though the shells resemble that of a nautilus. Ammonites appeared in the fossil record about 240 million years. The last lineages disappeared 65 million years ago at the end of the Cretaceous.