i8o EXTINCT MONSTERS. 



powerful claws, such as might be used for scratching up the 

 ground near the roots of a tree, and it was at one time thought 

 that this was the way in which the creature obtained its leafy food, 

 namely, by digging up trees by the roots and then devouring the 

 leaves. But Professor Owen had another explanation. 



As in the living sloths and armadillos (edentata 1 ), there are no 

 teeth in the fore part of the jaw. The molar teeth, of which there 

 are five on each side of the upper jaw, and four in the lower, are 

 hollow prismatic cylinders, straight, seven to nine inches long, 

 and implanted in deep sockets. There are no other teeth, but 

 these are composed of different substances, and so arranged that, 

 as the tooth wears, the surface always presents a pair of trans- 

 verse ridges, thus producing a dental apparatus well suited for 

 grinding up vegetable food. In the elephants, which live on 

 similar food, the grinding is effected by great molar teeth, which 

 are replaced by new ones as the old ones are worn away. In the 

 Megatherium, however, only one set of teeth was provided ; but 

 these, by constant upward growth, and continual addition of new 

 matter beneath, lasted as long as the animal lived, and never 

 needed to be renewed. 



On looking at the model so skilfully set up at South Kensington, 

 and especially at the front part of the skull, it will be seen that 

 the snout and lips must have been somewhat elongated, possibly 

 into a slight proboscis like that of the tapir. The specimens of 

 the lower jaw in the wall-case close by show that it was much 

 prolonged and grooved. This fact must be interpreted to mean 

 that the creature possessed a long and powerful tongue, aided by 

 which it could, like the giraffe, strip off the small branches of the 

 trees which it had broken or bent down within its reach. 



A bony shield (or carapace) of a great armadillo was found 

 with one of the specimens described by Mr. Clift, and Buckland 

 and others thought it belonged to the Megatherium ; but Owen 



1 This word, which means toothless^ is misleading. All the edentata, how 

 ever, agree in having no front, or incisor, teeth. 



