HISTORY OF THE EDENTATA 601 



teeth. The general opinion as to its manner of Ufe is well 

 summed up by von Zittel : "The hip-bones, hind legs and tail 

 are characterized by enormous strength. The entire structure 

 of the extremities proves that the gigantic sloth could move 

 over the ground but slowly and clumsily ; on the other hand, 

 the fore limbs served as grasping organs and were presumably 

 employed to bend down and break off twigs and branches and 

 even to uproot whole trees, whUe the weight of the body was 

 supported upon the hind legs and tail." ^ It would be quite 

 absurd to suppose that such ponderous animals could have 

 been climbers or burrowers, hence the fimction of the enormous 

 claws, especially the single one of the pes, is not obvious, though 

 they may have been merely the weapons of the otherwise 

 defenceless monsters. The great claw in the fore foot of the 

 Ant-Bear is a terrible weapon, with which the creature vigor- 

 ously and successfully defends itself against dogs, and it may 

 even be dangerous to men, if incautiously molested. 



^Megatherium had no bony scutes, or other ossifications in 

 the skin, so far as is known, and was probably covered with 

 long and coarse hair, as is known to have been the case in 

 another fgroimd-sloth. 



Less specialized in many respects than the t^fiegatheres 

 was \Mylodon, tj^e of a family which was numerously and 

 variously represented in the Pleistocene of South America, 

 much less so in that of North America '\Mylodon was smaller 

 and Ughter, being from J to j smaller in linear dimensions 

 than ^Megatherium, and the contemporary \Scelidotherium 

 was no bigger than a tapir. The teeth nimibered f and the 

 anterior one above and below had a somewhat tusk-like form ; 

 the others were worn off evenly, with nearly horizontal grind- 

 ing surface, but a vertical groove on the inner side gave them 

 a subtriangular, lobate form. The skull was short and broad, 

 with flat top, and orbit only partially enclosed behind; the 

 premaxiUaries were very short and the muzzle very broad and 

 ' K. von Zittel, Handbuch der Palaeontologie, Bd. IV, p. 132. 



