This is a slice of a 3.9" tall, vertebrae of a Pliosaur, a large Cretaceous, marine reptile. It was collected in the Ulyanovsk Region region of Russia. The vertebrae though, heavily eroded on the outside exhibits beautiful cell preservation and pyrite replacement on the interior. The slice has been polished to a mirror like finish one one side, while the opposite shows the exterior surface of the vertebrae.
Comes with an acrylic display stand.
Pliosaurs are a group of large, long-necked, predatory marine reptiles that included such monsters as Liopleurodon which is estimated to have grown up to 50 feet in length.
Liopleurodon ferox, a pliosaur from the Late Jurassic of Europe, pencil drawing by Nobu Tamura (http://spinops.blogspot.com).