5.6" Jurassic Ammonite (Hildoceras) Fossil - England
This is a large, 5.6" wide Hildoceras bifrons ammonite from Whitby, England. It was found within a large concretion which was broken open to reveal the fossil. The majority of the surrounding rock has been removed, with portion of rock remaining for presentation purposes. The edge of the rock has been cut flat, allowing for the specimen to stand up nicely on a flat surface.
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.