The Orthoceras is a single genus within the cephalapods, a class of molluscs.

The ortoceras is characterized by a nearly straight conical shell which superficially resembles those of Baculites a kind of ammonite. In fact, they so closely resemble Baculites that the two designations are often used interchangeably by less educated fossil merchants!

Sometimes Orthocerans formed massive death assemblages and could even be rock forming.

To picture what Orthocerans were like in life, you would have to imagine the world they lived in. Picturing an Orthoceras in today's world alongside contemporary organisms would be even more absurd than a dinosaur wandering around New York's Central park!

As with Ammonites, the closest living realtive is the Nautilus

Orthoceran fossils are so abundant that they are often made into Jewelry and a variety of other products!