Collection: Ammonites and other Cephalopods

Ammonites are shelled cephalopods (mollusks with tentacles like squid and octopi) that lived throughout the worlds oceans. They first appeared 409 million years ago before going extinct with the non-avian dinosaurs 66 million years ago. Scientists have documented over ten thousand species of Ammonites! Most had a shell that coiled into itself while others had straight shells, partially coiled shells, and shells that coiled out into bizarre patterns. Ammonites ranged widely in size with shells ranging from half an inch to over six feet across depending on the species. The species of ammonite is determined by the shape of the shell and the pattern that divided the individual chambers within the shell called sutures. There are other shelled cephalopods besides Ammonites such as Goniatites, and the Nautiloids which still survive today. The fossil shells are important index fossils for paleontologists, and prized collectibles with a wide range of colors, suture patterns, and ornamentation. They're sea shells and gemstones in one package, what's not to love?