246 LAND MAMMALS IN THE WESTERN HEMISPHERE 



the carapace rarely exceeding two feet in length, and, what 

 it is particularly interesting to note, they departed much less 

 widely from the armadillo type than did their gigantic suc- 

 cessors. The tground-sloths were present in actually bewild- 

 ering variety and they also were very small as compared with 

 the huge animals of the Pleistocene, none of them exceeding 

 the Black Bear in height or length, though proportionally 

 much more massive, and many were no bigger than foxes. 

 They had small heads, long bodies, heavy tails and short, 

 thick legs ; their teeth show that they were plant-feeders, but 

 their feet were armed with long, sharp and formidable claws. 

 Among this great host of Santa Cruz fground-sloths may 

 readily be noted the probable ancestors of the gigantic creatures 

 which were such characteristic elements of the Pliocene and 

 Pleistocene faunas. 



There was an extraordinarily rich and varied assemblage of 

 hoofed animals, all utterly different from those of the northern 

 hemisphere and belonging to groups which have never been 

 found outside of South and Central America. Of these groups 

 there were five, which by different writers are variously re- 

 garded as orders or suborders, a matter of very secondary im- 

 portance. Individually, the commonest of the hoofed mam- 

 mals were the fToxodonta, which ranged in size from a sheep 

 to a tapir, heavily built and clumsy creatures, with absurdl}^ 

 small, three-toed feet ; in some of the species there was a smah 

 median horn on the forehead. As with the fglyptodonts and 

 tground-sloths, the contrast in size between the Santa Cruz 

 ancestors and the Pleistocene descendants was very striking. 

 A very numerous and varied group was that of the fTypotheria, 

 all small animals, some no larger than rabbits, others the size 

 of small foxes. It requires a decided effort to think of these 

 ftypotheres as being really hoofed animals at all, as their 

 whole appearance must have been much more like that of 

 rodents, yet their structure clearly demonstrates their near 

 relationship to the jtoxodonts. Still a third group of the same 



