Originally Orthoceras referred to all nautiloids with a straight-shell , called an ("orthocone") . But later research on their internal structures, such siphuncle, cameral deposits and others, showing that there are actually a number of groups, even different orders, that they can belong to. The following are a couple of examples.
Many samples of Orthocaras are extremely large and are finished as desk or large display pieces as seen in the following picture.
However, smaller sized pieces make up into very interesting pendants, and sometime earrings.
A wire-wrapped Orthocaras in a pendant design by our daughter-in-law.