3.8" Jurassic Ammonite (Asteroceras) Fossil - Dorset, England
This is a beautifully preserved, 3.8" wide Asteroceras obtusum ammonite fossil from the Lyme Regis region of England. One half of the ammonite has been prepped free from the rock. The outer shell has been prepped away from much of the ammonite, revealing the gorgeous, leaf-like suture pattern beneath. The base of the rock has been cut flat for presentation purposes.
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.