Pachyrhizodus Upper Jaw
Nearly complete Pachyrhizodus upper jaw. Pachyrhizodus was a large predatory fish and the jaws (especially large ones) are often mistaken for mosasaur. Both the premaxilla and maxilla are present but both are incomplete. Teeth are a little over 1/4" long (above the root line). Several of the teeth appear much longer but this is because the bone is missing on the side of empty teeth sockets. These jaws often have every other tooth with an empty socket in between. The piece is saturated with a stabilizer. This fossil is from the Niobrara Chalk of Western Kansas.