AQUATIC REPTILES 



209 



order Mosasauria (Mosasaurus), taking its name from the 



River Meuse, was found in the uppermost marine Cretaceous. 



Detailed knowledge of the structure of these remarkable 



sea lizards is due chiefly to the researches of Williston and 



Fig. 87. A Sea Lizard. 



Tylosaurus, a giant mosasaur from the inland Cretaceous seas of Kansas, chasing the giant 

 fish Porlheiis. After a restoration in the American Museum of Natural History, by 

 Charles R. Knight under the author's direction. 



Osborn of this country and to those of Dollo in Europe. The 

 head is long and provided with recurved teeth adapted to seiz- 

 ing active fish prey (Fig. 87); the neck is extremely short; as 

 in the plesiosaurs the fore and hind limbs are converted into 

 paddles, symmetrical in proportion; the body is elongate and 



