This Specimen has been sold.
Beautiful Half Polished Ammonite - Purple Highlights
Here is a cut and polished Cleoniceras from Madagascar just shy of 6 inches wide. It is absolutely beautiful with natural purple highlights which I've only seen on a few specimens. The chambers of the ammonite have been agatized and the reverse side shows the distinctive "oak leaf" shaped sutures of this species. It's hard to believe this was alive 110 million years ago.
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.