An orthocone is the pointed shell of various species of prehistoric nautiloid cephalopods.nOrthocones were basically uncoiled nautilus shells, with a wide opening holding the soft tissue body and other chambers for buoyancy. Orthoconic shells ranged in size from less than 1 inch (2.5 cm) to 17 feet (5.2 m) long.nThey evolved several times independently, from the Late Cambrian to the Late Triassic period (497 to 201 million years ago). This fossil is from the Devonian, which lasted from 419 to 359 million years ago.nIt was long thought that orthoconic nautiloids lived horizontally in the water, but a 2021 study involving 3D printed orthocone reconstructions found that they likely lived vertically, giving them the ability to dart vertically away from predatornnsmall size includes 1 to 2 small specimens approximately 0.5″ – 0.75″nlarge size includes 1 large specimen approximately 1″ – 2″