52 Life of a Fossil Hunter 



collection. You will notice the triangular shape of 

 the head, with the strong bones arching back to sup- 

 port the lower jaw by the pulley-like quadrate bone. 

 Notice also that the suspensorium, instead of curv- 

 ing down so that its groove fits over the rounded 

 edge of the quadrate, is straightened out. This is 

 caused by its having been flattened and distorted, 

 as nearly all fossils are, by the immense pressure to 

 which it has been subjected Observe the conical 

 shape of the head in front of the eye-rim, terminat- 

 ing in the hard, blunt rostrum. It is believed by the 

 authorities that a blow from this ram, delivered at 

 full speed, would put an adversary out of commis- 

 sion. 



But how did this creature feed itself, when all 

 its teeth are for grasping, none for masticating? 

 And how did it hold its prey, when it has no claw- 

 armed fingers, only weak paddles for swimming? 



In answering these questions, we shall describe 

 two characteristics of the mosasaurs which differen- 

 tiate them from all other reptiles. 



If you will look closely at the photograph, you 

 will notice, within the head, and below the eye- 

 socket, a row of recurved teeth. These are the 

 teeth on the pterygoid bones, which are located on 

 either side of the roof of the mouth, near the gullet, 

 and are provided with twelve teeth, more or less. 

 The lower jaw with its powerful sweep on its ful- 



