Description

These Moroccan fossils are among the oldest cephalopods.  They were abundant during the Paleozoic era some 350 MM years ago and now make up the Atlas Mountain range of central Morocco. There were two Nautiloid forms present in the Moroccan Devonian Sea.  The Goniatites is an extinct relative of the Ammonites, it possessed an external shell, which is has a spiral form with internal chambers. The Orthoceras was straight shelled cephalopod with the internal chambers. They were related to the modern-day chambered nautilus and the squid.

Orthoceras is a genus of extinct Nautiloid Cephalopod.  These fossils are common and have a global distribution which occur in any marine rock, especially Limestone.  These are slender, elongated shells with the middle of the body chamber transversely constricted and a sub-central orthochoanitic siphuncle.  The surface is ornamented by a network of fine lirae or fine lines/ridges.