8.2" Stephanoceras Ammonite - Dorset, England
This is is a nicely prepared and uncommon Stephanoceras ammonite from the Dorset Coast region of England. This one is quite large at 8.2" wide and makes a stunning display. The base of the rock has been cut flat so that it stands up nicely without the need for a display stand.. It's Middle Jurassic, Bajocian Stage in age or approximately 160 million years old.
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.
Burton Bradstock, Dorset, Great Britain
Ammonite 8.2" across