SEE MORE STRAIGHT CEPHALOPOD FOSSILS
This is a group of eighty-eight (88) polished orthoceras cabochon fossils. They average size varies from 1.5" - 3" long. The fossils are completely genuine and still encased in the original stone they were found in. The fossils are located in the host rock, then broken or sawn out of a large block. Each individual fossilized orthoceras creature is then separated by grinding the stone around them to reveal the fossil and then polish the stone so that the inner detail can be seen. They are completely natural except for the fact that the shape is from grinding and polishing the original rock they are found in.
These would be great as teaching aids, gifts, for unique jewelry, make-shift fossil treasure hunts for kids, or epoxy on furniture hardware to make cool knobs and pulls!
Prehistoric 'straight' cephalopods include straight ammonoids called ORTHOCERAS. Cephalopod evolution began during the Late Cambrian Period. Cephalopod bodies were predominantly elongate with conical shells. Some of these creatures evolved into semi-coiled forms eventually giving rise to coiled cephalopods like ammonites and nautilii.
Straight cephalopods were among the most advanced invertebrates of their time having eyes, jaws, and a sophisticated nervous system. These creatures were predators that swam freely using a jet propulsion system by squirting water from their bodies. They had tentacles and ink sacs also much like the present-day squid. Except for belemnites, cephalopods had external shells with hollow internal chambers separated by walls called septa. A tube called the siphuncle, connected the body with the chambers allowing the animal to fill them with water or air, changing its buoyancy in order to rise or drop in the ocean. Only the last and largest chamber was occupied by the living animal. Belemnites were different in that they had internal shells called 'guards' which were covered with the soft, muscular tissues of their bodies. These shells were also chambered but much less complex than the straight varieties of nautiloids and ammonoids.