Mosasaur meaning jaw fossil in limestone containing five teeth. Mosasaur's comprise a group of extinct marine reptiles containing 38 genre in total. Mosasaur's probably evolved from an extinct group of aquatic lizards known as Aigialosaurs in the earliest late Crustaceous period. During the last 20 million years of the Crustaceous period. With the extinction of the icthyosaurs and pilosaur's, mosasaur's became the dominant marine predators. They became extinct as a result of the K - PG event at the end of the Crustaceous period about 66 million years ago.
SIZE: 7" x 8" x 1 1/2"