Orthocerous Fossils
ORTHOCERATOIDS are common fossils from the Paleozoic age. Part of the cephalopod group that today has squid and nautilus in it, the orthoceratoid is really just a straightened or uncoiled ammonite shape, sharing the same chamber design used for ballast, with a through-hole (siphuncle) that allowed the animal to trim its depth by adding or removing fluid. Sometimes called 'pagoda stones' because they resemble Chinese temples, many orthoceratoids are found in extensive fossil beds in Morocco, North Africa.