This Specimen has been sold.
9.1" Jurassic Ammonite (Kranosphinctites?) - Madagascar
This is a 9.1" wide ammonite (Kranosphinctites?) fossil that was collected near Sakaraha in the Tulear Province of Madagascar. It is Jurassic (Oxfordian Stage) in age or approximately 160 million years old. It has a well defined ribbing and it's quite heavy. The exterior has been lightly polished and it comes with 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. True ammonites appeared in the fossil record about 240 million years ago. The last lineages disappeared 65 million years ago at the end of the Cretaceous.