CROCODILIA 203 



The third family, the Gavialidae, also comprises but two living 

 species, both restricted in habitat to the rivers of India. Of these 

 the famed gavial of the Ganges is the better known and the more 

 highly specialized. The skull of this species has an exceedingly 

 long and slender snout; the teeth are numerous, small, and slender; 

 and the feet are more fully webbed than are those of other members 

 of the order. In habits the gavials are more distinctly aquatic 

 than are the crocodiles and alligators. They feed almost exclu- 

 sively upon small fishes, for the seizure and retention of which their 

 small and sharply pointed teeth are admirably adapted. The 

 hind feet are relatively long, a character that will be better under- 

 stood when comparison is made with those of the Thalattosuchia. 

 Although attaining a large size, fully twenty-five feet in length, 

 they are comparatively harmless animals, never attacking human 

 beings or other large animals, as do some of the crocodiles proper. 

 The gavials have lived a long time in the Indian regions, the 

 Gangetic gavial itself having been found in deposits of Pleiocene 

 age, perhaps the oldest known of all living species of air-breathing 

 vertebrates. Some of the extinct gavials of the same region 

 attained a length of nearly or quite fifty feet, possibly the longest, 

 if not the largest, of all swimming reptiles of ancient or modern 

 times. Extinct gavials have been reported from South America, 

 but are not yet fully known. 



While the fish-eating gavials swallow their prey whole, the 

 crocodiles, caimans, and alligators prey upon all living animals that 

 come within their reach, whether large or small, and they will often 

 leave the water to seize their intended victims, such as pigs, sheep, 

 birds, or even human beings. Their teeth, as has been already 

 stated, are much larger, longer, and more irregular in size than 

 those of the gavials. Their victims are often drawn under the water 

 and drowned, the peculiar posterior position of the internal nos- 

 trils permitting the animals to breathe with the mouth and to 

 firmly hold their prey under water, while the extremity of the snout 

 and the external nostrils are above the surface. 



As the firm, unyielding bony palate, the fixed position and 

 articulation of the lower jaws, and their rigid attachment to each 

 other in front do not permit creatures of large size to enter the gullet 



