1 88 EDENTATA 



phalanges, and no claws. The creature probably walked upon the 

 outer edge of the sole, so that the great falcate claw of the third 

 toe did not come into contact with the ground, and so was kept in 

 a state of sharpness ready for use. The foot was therefore formed 

 upon quite a different principle from that of the Anteaters or 

 Sloths, though somewhat like the latter in having two of the toes 

 aborted. 



Taking all the various points of its structure together, they 

 clearly indicate affinities both with the existing Sloths and with 

 the Anteaters, the skull and teeth more resembling those of the 

 former, and the vertebral column and limbs the latter. It is also 

 not difficult to infer the food and habits of this enormous creature. 

 That it was a leaf-eater there can be little doubt ; but the greater 

 size and more complex structure of its teeth might have enabled it 

 to crush the smaller branches as well as the leaves and succulent 

 shoots which form the food of the existing Sloths. It is, however, 

 very improbable that it climbed into the branches of the trees like 

 its diminutive congeners, and it is far more likely that it obtained 

 its subsistence by tearing them down with the great hook-like claws 

 of its powerful prehensile fore limbs, being easily enabled to reach 

 them by raising itself up upon the massive tripod formed by the 

 two hind feet, firmly fixed to the ground by the one huge falcate 

 claw, and the stout, muscular tail. The Avhole conformation of 

 the hinder part of the animal is strongly suggestive of such an 

 action. There can also be little doubt but that all its move- 

 ments were as slow and deliberate as those of its modern repre- 

 sentatives. 



An idea at one time prevailed that the Megatherium was 

 covered externally with a coat of bony armour like that of the 

 Armadillos ; but this originated in dermal plates belonging to the 

 Glyptodon having been accidentally associated with bones of the 

 Megatherium. Similar plates, on a smaller scale, have indeed been 

 found in connection with the skeleton of the Mylodon, but never 

 yet with the Megatherium, which Ave may therefore imagine with 

 a covering of coarse hair like that of its nearest living allies, the 

 Sloths and Anteaters. 



Scelidotheriv/m, Mylodon, etc. — Of the more important remaining 

 genera of this family a briefer notice will suffice. Scdidotherium (in 

 which Platyonyx may be included) comprises several species of 

 considerably smaller dimensions than the Megatherium, and is in 

 some respects intermediate between that genus and Mylodon. The 

 teeth have an oval cross-section, like those of the Sloths, while the 

 skull, in which the length of the nasals is subject to great variation 

 in the different species, approximates more or less closely to that 

 of the Myrmecophagidce. The humerus generally has an ent- 

 epieniiilylar foramen ; and the form and relations of the bones of 





