We offer numerous AUTHENTIC ammonite fossils for sale, all prepared by us in our on-site lab. This is important because in doing so, we can ensure their authenticity and nature of all work performed in the process. Every ammonite fossil we sell includes a written lifetime guarantee of authenticity & condition report / history sheet.
Ammonites are extinct invertebrates. They belong to the subclass Ammonoidea, class Cephalopoda. Ammonites shared the same fate as the dinosaurs and died out at the end of the Cretaceous Period, 65 million years ago. It is a mystery as to why their modern relatives, the nautilus, squid, cuttlefish and octopus, did not go extinct. Ammonites first appeared during the Middle Devonian Period around 400 million years ago. They became especially abundant and widespread in the seas of the Jurassic and Cretaceous periods, 175 million to 65 million years ago. Ammonites were so plentiful throughout various stages of geologic history that scientists use them as INDEX FOSSILS whereby the presence of certain types in a rock layer can denote a specific time period.
Ammonites were mollusks with shells that were predominantly tightly coiled on a single plane like a wheel. These are called HOMOMORPHS. There are also other varieties called HETEROMORPHS which include members that have open helical-coiled and irregular-coiled shells, as well as straight shell examples. The soft-bodied animal living in this shell most-likely resembled an octopus but with shorter arms. Fossils are few and rare showing any soft body tissue so the concept of what the soft parts of these creatures looked like is speculative. Only the last and largest chamber was occupied by the living animal. As it matured and grew, larger chambers were added at the opening.
Ammonite fossils are mostly natural stone casts or flattened compressed impressions of the former outer shell which left a cavity that served as the mold when first buried in prehistory. If three-dimensional, these fossils may also contain remnants of the internal chamber anatomy sometimes seen if sliced open. In most cases, the actual outer shell is gone. Some rare instances in the fossil record show preserved ammonites that have retained the actual outer shell of the animal. These ammonites may still retain original coloring which may display pearl essence or iridescent phenomena due to the presence of the original mother-of-pearl layer in the fossilized shell.