A beautifully polished ammonite disc fossil comprising various-sized ammonites. Ammonites are a form of ammonoid which are distinguished by their complex suture lines. They evolved very rapidly to produce numerous species and genera, but it was during the Late Cretaceous period that the ammonites and other marine groups, like belemnites, and terrestrial groups, like dinosaurs became extinct. 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 because 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. A beautiful example and a decorative piece with fine detail. Size: 81mm diam