Orthoceras rough/polished #2

Orthoceras was a very successful cephalopod that lived from Ordovician to the Triassic. This species is often found as fossil because of the amount of Orthocerata that swam around and the fact that their shell fossilizes so well. Orthoceras fossils are mainly found in black limestone, where it shows up as a white imprint of the shell, made of calcite. The name Orthoceras is Greek for ‘straight horn’, of course referring back to the shape of the shell. Orthoceras is a kind of Nautiloid, which makes it a close relative of ammonites, squid, cuttlefish and octopuses. The shell of an Orthoceras functioned comparably to one of an Ammonite; the Orthoceras lived in the last chamber and used the rest of the chambers to store either gas of water, to be able to rise and sink fast in the water. Orthoceras was a fast swimmer and could even spray ink to escape predators.