POST-TERTIARY PERIOD. 



565 



species than now exist in that part of the continent, and far larger 

 species. 



The Edentates — including the Sloth, Armadillo, and allied species 

 — were the most remarkable. The animals of this order are stupid 

 in aspect and lazy in movement and attitude. 



The Megatherium (fig. 841) exceeded in size the largest Rhinoceros. 

 The length of a skeleton in the British Museum is 18 feet. Its 

 massy limbs were more like columns for support than organs of 

 motion. The femur was three times as thick as an elephant's ; the 

 massive tibia and fibula were soldered together ; the huge tail was 

 like another hind leg, making a tripod to support the heavy carcass 

 when it raised and wielded its great arms ; and the hands termi- 

 nating the arms were about a yard long, and ended in long claws. 

 The teeth had a grinding surface of triangular ridges, well fitted 

 for powerful mastication. 



A species of Megatherium has been found in Georgia at Skiddaway 

 Island, different from that of the Pampas. 



Megalonyx is another genus of these large Sloth-like animals. 

 Bemains of species occur over the Pampas to the Straits of Ma- 

 Fig-. 842. 



Claw of Megalonyx Jeffersonii. 



gellan ; but the first species known was found in Virginia, in Green- 

 Brier co., and named by Jefferson in allusion to its large claws 

 (fig. 842). Its bones have also been found at Big Bone Lick and 

 elsewhere. 



Mylodon is a third genus, and three species have been described,— two from 

 South and one from North America. The skeleton of one, 31. robustux, is 11 feet 

 in length ; and the animal was therefore much larger than the western Buffalo. 



