Orthoceras Fossil

Orthoceras were straight-shelled nautiloid cephalopods that lived in the ancient seas of the Ordovician through Triassic periods and are among the most distinctive and widely collected Paleozoic fossils. Moroccan specimens are typically preserved in dark grey to black limestone and are often polished to show the internal chamber structure. Modern nautilus species are true living fossils with a body plan largely unchanged for over 400 million years.