Beautiful Ammonite Cluster (Asteroceras & Promicroceras) - England
This is a gorgeous cluster of three, exquisitely prepared ammonite fossils from the Lyme Regis region of England. There is a 1.4" wide Asteroceras obtusum and two smaller Promicroceras planicosta in close association. The rock around them has been painstakingly removed, so that they are displayed in high relief against the rock. The base of the rock has been cut flat so that it stands up nicely without the need for a display stand.
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 ago and they barely survived several major extinction events. The last lineages disappeared 65 million years ago at the end of the Cretaceous.