6.35" Polished Jurassic Ammonite (Perisphinctes) - Madagascar

Polished Jurassic Ammonite (Perisphinctes) - Madagascar #270940

This is a 6.35" wide ammonite (Perisphinctes sp.) 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 well-defined ribbing and is quite heavy for its size. The exterior has been lightly polished.

This ammonite is accompanied by an acrylic display stand.

Ammonites were predatory cephalopod mollusks that resembled squids with spiral shells. They are more closely related to living octopuses, though their shells resemble that of nautilus species. True ammonites appeared in the fossil record about 240 million years ago during the Triassic Period. The last lineages disappeared 65 million years ago at the end of the Cretaceous.

What an ammonite would have looked like while alive.

More about ammonites