TITANOTHERES AND OTHERS 105 



member that the rocks in which the Titanotherium is 

 found extend to a depth of one hundred and eighty 

 feet and that below this one hundred and eighty feet 

 are many deep layers of rocks containing all the other 

 sizes of Titanotheres, we can gain some faint idea of 

 how long this family of animals lived. And we 

 know that they ceased to exist while at the highest 

 point of their growth, because the bones of the largest 

 members of the family are in the upper layer of rocks. 

 But why did the Titanotheres disappear just at 

 the time when it would seem they were well prepared 

 to hold their own against all odds ? This is a ques- 

 tion that has puzzled even the most learned among 

 the men who have studied these animals. Some, 

 however, believe that they slowly starved to death. 

 They were plant eaters, and unfortunately for them 

 the climate began to grow cold after they had de- 

 veloped into, huge creatures. This meant that the 

 trees and grasses were tougher and less plentiful, 

 and so, as the teeth of the Titanotherium were suited 

 only to the crushing of soft and juicy food, this 

 lumbering, slow-witted beast had a hard time of it. 

 Had he been a larger-brained animal, he might 



