Orthoceras, Fossil Cephalopod Tower AFossilized orthoceras "armoured squids" for sale! Orthoceras, which somewhat resembled a squid, was a straight shelled member of the nautilus family (nautiloid cephalopod). This species is extinct and these Moroccan fossils date back roughly 400 million years. Price is per specimen and all of our fossils can be shipped worldwide! They measure roughly 14" tall.