Ammonite Fossil Ammonite Pendant Necklace, Ammonite Fossil Pendant, Ammonite Necklace 14.23 carats 25 x 19 x 3 mm Metaphysical guide of Ammonites, Physical Properties of Ammonites AMMONITE Ammonites are an extinct group of marine invertebrate animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs are more closely related to living coleoids (i.e. octopuses, squid, & cuttlefish) than they are to shelled nautiloids such as the living Nautilus species. Ammonites are excellent index fossils, & it is often possible to link the rock layer in which they are found to specific geological time periods. Their fossil shells usually take the form of planispirals, although there were some helically-spiraled & non-spiraled forms (known as heteromorphs). The name ammonite, from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly-coiled rams’ horns. Pliny the Elder (d. 79 A.D. near Pompeii) called fossils of these animals ammonis cornua (horns of Ammon) because the Egyptian god Ammon (Amun) was typically depicted wearing ram’s horns. Often the name of an ammonite genus ends in -ceras, which is Greek () for “horn”. Originating from within the bactritoid nautiloids, the ammonoid cephalopods first appeared in the Late Silurian to Early Devonian (circa 400 million years ago) & became extinct at the close of the Cretaceous (65 Ma) along with the dinosaurs. The classification of ammonoids is based in part on the ornamentation & structure of the septa comprising their shells’ gas chambers; by these & other characteristics we can divide subclass Ammonoidea into three orders & eight known suborders. While nearly all nautiloids show gently curving sutures, the ammonoid suture line (the intersection of the septum with the outer shell) was folded, forming saddles (or peaks) & lobes (or valleys). Metaphysical guide of Ammonite: Ammonites are a fossilized animal related to the snail. Ammonites transmute negative energy. Ammonites provide stability & structure as well as protection for the user. Vibration: 9 Astrological Sign: Aquarius" Ammonite Fossil Pendant Necklace, Pendant, Necklace