40 



ANIMALS OF THE PAST 



The Giant Sea Turtle Ahchelon 



A contemporary of the Mosasaurs 



From the specimen in the Yale University Museum 



If they came to the surface they were snapped up by 

 Pteranodon; if they sought safety in deep waters 

 Portheus pounced upon them, while at intermediate 

 depths Hesperornis made their lives miserable and 

 existence precarious; small wonder that, like the huge 



