This Specimen has been sold.
1.55 Inch Subdichotomoceras Ammonite
Here's a classic Late Jurassic Jurassic fossil from Madagascar. It's just over 1.5 inches wide and still has some of the original matrix attached to it.
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.