Zentron Crystal Collection Black Orthoceras Fossil Polished Large Specimen 4 to 6

Orthoceras lived about 488 million years ago, in the Middle Ordovician period. They were mollusks, related to today’s octopus, squid, cuttlefish, and – more closely, Natulius. They were varied in size, growing up to 14 feet long. Orthoceras used its shell for a form of jet propulsion, filling its shell with compressed water and forcing it out to propel backwards through the ocean. It is thought these could reach lengths of over 14 feet long. These roamed all the Earth's oceans and can be found now fossilized throughout the globe.