i84 



ARMOURED EDENTATES 



On the manus, the three inner digits ha^'e powerful claws. This 

 animal, too, was Pleistocene in time. The Megatheriidae had, 

 however, small as well as gigantic forms. 



The genus Zamicrus had a skull no bigger than that of a 

 Sloth, while Nothrothcrium was also a comparatively small 

 creature ; the teeth of the latter genus are reduced to ^. 



The extinct group of the Glyptodontidae comprises large 

 creatures with a dense covering of bony scutes which are arranged 

 in a tesselated fashion, and thus form an immobile armature of 

 immense strength. In correspondence with this massive carapace 

 the dorsal vertebrae have fused together, and the lumbar vertebrae 

 form a series ankylosed to each other and to the following sacrals. 

 These creatures are all South American. 



Glyptodon, the genus which gives its name to the family, is 

 known from numerous remains in South America, and also from 



Fig. lOQ. — (i I [I ptodoH davipcs. 



(After Owen.) 



so far north as Texas and Mexico. It grew to be as long as 16 

 or 17 feet. In the skull there is an exceedingly long 

 downward process of the zygomatic arch, as in Sloths, the arch 

 itself being complete. The process extends so far down as to 

 reach a point about on a level with the middle of the lower jaw. 

 The nasals are short or rudimentary. As in MijTmecophaga, the 

 pterygoids enter into the formation of the bony palate. The 

 lower jaw has a spout-shaped extremity, and, behind, it rises into 

 an enormous vertical branch as high as the front part of the jaw 

 is long. There are eight teeth in each half (jf each jaw\ As in 



