Polished Ammonite Fossil with Suture PatternsThese Madagascar ammonites went extinct in the Cretaceous period. Resembling octopi with shells they hunted the oceans roughly between 240 million years and 66 million years ago. Their shells were filled with gas for buoyancy, but that gas has long been replaced with minerals of all kinds. These polished fossils feature rare full suture patterns decorating the exterior. Perfect for museums, nautical and ocean attractions, gift shops, and educational