Orthoceras was a marine cephalopod, this particular species was straight shelled and they thrived some 400+ million years ago in the Paleozoic era.
This is a very nice fossilized Orthoceras collage from Morocco from the Silurian Age about 400 million years ago. The specimen has many highly detailed Orthoceras fossils in various sizes scattered throughout measuring from 2 1/4″ to 4 1/2″ long. Overall, the matrix measures 10″ x almost 6 1/2″ x nearly 2″ thick and is not polished. Very cool!