Tylosaurus is not a dinosaur, but instead is a mosasaur - an extinct group of seagoing reptiles that are closely related to modern lizards and snakes. Mosasaurs first appeared about 100 million years ago and rapidly spread around the world, even to Antarctic waters. They vanished along with dinosaurs at the end of the Cretaceous Period (the third and final period of the Age of Dinosaurs) about 66 million years ago. A hunter of large fishes and smaller marine reptiles, Tylosaurus is one of the largest and best-known mosasaurs.For over 25 years, Safari Ltd. has been proud to provide this premier line of scale model, dinosaur collectibles. These award winning dinosaur replicas are authenticated by the paleontologists of the Carnegie Museum of Natural History, who houses the largest collection of dinosaur fossils in the world. Each Carnegie dinosaur can have up to 25 steps of hand painting to ensure the highest quality in the world marketplace.