Ammonites

Ammonites are an extinct group of mollusks in the subclass Ammonoidea of the class cephalopoda. The ammonites are more related to octopus and squids than nautiloids (shelled cephalopods), such as the living nautilus. The first species appeared in the Devonian period, then died out in the late crutaceous- paleogene period, but fossils can still be found today.