The Ostrea crassissima is a genus of marine oysters, a bivalve mollusc from the family of Ostreidae. This oyster belongs to an extremely long-living genus, since these fossils can be found from the Permian up to the Quaternary, 259–0 million years ago, and was widespread throughout the world. Here we have a beautiful large size specimen (26 cm wide), coming from France, dated 16 million years ago, in Burdigalian. The specimen is in excellent condition, remarkable for the layered composition of the shell, which conveys a sense of the ancientness to this fossil. Oyster dimensions: 26 x 10 x 10 cm Weight: 2900 g Epoch: Miocene, Burdigalian, 16 Ma Origin: Villeveyrac, France