The Rise of tlie Mammals 



a whale, and yet more like to a whale than to 

 any other animal with which we are familiar. 

 The head was very small in comparison with 

 the body, and the greater part of this corre- 

 sponds to the tail of other animals, so that 

 no less than three-quarters of the length and 

 bulk of Zeuglodon consisted of tail. The for- 

 midable array of teeth, adapted for seizing and 

 cutting, show that the animal was predatory in 

 its habits ; but what could have been the use 

 of such a tail? The individual vertebrae are 

 18 inches long, the longest known. The heavy 

 bones of the manatee are supposed to be for 

 the purpose of enabling it to feed off the bot- 

 tom with ease, and the long tail of Zeuglodon 

 may have acted as a counterpoise, so that the 

 animal could rear his body out of water, some- 

 what as Diplodocus is thought to have done. 



In the Eocene, too, snakes make their first 

 appearance, small species on land, large ones in 

 the sea or rivers, for their bones are found 

 associated with those of Zeuglodon and other 

 aquatic animals. These sea-snakes reached a 

 length of 15 or even 25 feet, and are the 



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