This Specimen has been sold.
2 1/2 Inch Desmoceras Ammonite
Here is a Desmoceras ammonite from Madagascar that has been cut and polished to reveal all of the detail of the inner chambers.
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.