THE ICE AGE 



The peculiar productions of South America in the way 

 of animals appear to be the members of the group of 

 mammals called Edentata found nowhere else. When, 

 however, South America, which once was an island, 

 joined on to North America, numbers of animals, 

 mastodons, horses, tigers, and tapirs, emigrated from 

 north to south, and perhaps proved too much for the 

 aboriginal or native beasts. At any rate, all the 

 big South American mammals died out, and now 

 there are left only the small tree sloths, the small 

 armadillos, and the strange-looking ant-eaters. But 

 in quite late geological deposits of South America 

 we find the bones of gigantic armadillos and of gigantic 

 ground sloths, which lasted on till the time when man 

 appeared on the scene. 



The Gtyptodon, of which there were several different 

 kinds, was an enormous armadillo as big as an ox. Like 

 their small, puny, modern descendants, they carried on 

 their backs a hard case of bones, something like the shell 

 of a tortoise. The modern armadillo's shell, however, is 

 jointed so that the little animal can roll itself up into 

 a ball, and in this direction, therefore, the armadillo, 

 though it has decreased so much in size, has advanced 

 in adaptability. 



The Megatherium was nearly as big as an elephant, and 

 its skeleton, though so much larger, is very similar to 

 those of the small sloths of present-day South America. 

 Its teeth also are very much like theirs. But whereas 

 the living sloths climb trees, as they have learnt to do, 

 the Megatherium's method was more primitive though 



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