Ammonites Disc Fossil with stand two pieces. Diameter: 11.5 cm / Thickness: 6.0 cm / Weight: 156,6 grams Diameter: 11.8 cm / Thickness: 6.0 cm / Weight: 148,2 grams The name ammonite, was inspired by the spiral shape of their fossilized shells, resembling tightly coiled rams’ horns. Many ammonoids probably lived in the open water rather than at the sea bottom, this is due to the fact that their fossils are often found in rocks that were laid down under conditions where no bottom-dwelling life is found. They are typically evolute with the inner whorls exposed, but some are commonly stout and more involute and strongly ribbed with pronounced tubercles. Shipping registered.