Pyritized Ammonite

An extinct group of shelled cephalopods that lived about 400 to 65 million years ago, ammonites are related to the modern day squid, nautilus and octopus. The beautiful fossils we enjoy are remnants of their coiled, external chambered shell. Pyritized Ammonites are ammonites that were buried deep in the ocean, and had their soft body parts replaced by iron sulphide.  This process is called “pyritization”.