The American Alugator 



8 



age of reptiles, the direct ancestors of modem croco- 

 diles and alligators being contemporaries of the 

 dinosaurs, the flying reptiles, and the gigantic sea 

 lizards of the late Cretaceous period. Just as might 

 be expected from their semi-aquatic habits, we find 

 that some of these ancestral forms had taken to 

 marine life and become almost wholly aquatic, per- 

 haps coming ashore only for egg-laying. 



There is great variation among the- twenty 

 living species of crocodilians in the length and breadth 

 of the snout. The greatest degree of elongation of 



Flgl. 



Skulls of Alligator (AlUifator miitaiitaippiensis) Crocodile 

 (Crocodylug americanus) , aud Gavial {Gacialis gangeticus) , from 

 left to right 



the snout is shown by the Indian gavial (Gavialis 

 gangeticus.) The Indian name, "gharial," of which 

 gavial is a corruption, means fish eater. Fish do in 

 fact form the chief part of its food. They are caught 

 by sudden sidewise lunges of the head and neck. In 

 this movement a long slender snout offers much less 

 resistance to the water than a broad one. The fre- 

 quent tendency to elongation of the snout in other 



[27] 



