Dear all, This piece was found in middle or upper jurassic sediments in the North of France (probably upper). Sediments are marine. You can usually find ammonites and sometimes bones of ichthyosaur or plesiosaur. However, fragments of land dinosaurs have been found (megalosaurus, iguanodon). The morphology of this piece resembles a big bone. I can also see some typical structure (see the small pictures). The white stuff inside does not look like bone. Could this be a big hollow bone that was f