MESOZOIC ERA. AGE OF REPTILES. 



355 



nated in the Jurassic, in America they seem to have cul- 

 minated in the uppermost Jurassic and Cretaceous. The 

 great interior Cretaceous sea and adjacent land seems to 

 have swarmed with marine and land reptiles of incredible 

 size. All the kinds already spoken of under the Jurassic 

 were found also in the Cretaceous, and in addition, one 

 order, the Mosasaurs wholly 

 characteristic of the Cretace- 

 ous, The accompanying sched- 

 ule will give some idea of the 

 number of species, and the 

 kinds, of these reptiles. We 

 shall not again describe most 

 of these, but only mention a 

 few interesting points : 



The marine saurians were 



represented in America only by the long-necked kinds 

 ( Plesiosaurs) ; but these were numerous, and some greatly 

 surpassed in size any European species, attaining even 

 fifty feet in length. 



Plesiosaurs, 13 species. 



Dinosaurs, 21 " 



Crocodilian s, 14 " 



Pterosaurs, 7 " 



Chelonians, 48 " 



Mosasaurs, 50 " 



Total, 153 



FIG. 319. Hypsilophodoii, x .. (Restored by Marsh.) 



