1.85" Cretaceous Pyritized Ammonite (Kosmoceras) Fossil - England

Cretaceous Pyritized Ammonite (Kosmoceras) Fossil - England #262643

This is a beautifully pyritized, 1.85" wide Kosmoceras ammonite fossil from the Lower Cretaceous-aged Upper Greensland Formation of England.

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.