596 LAND MAMMALS IN THE WESTERN HEMISPHERE 



large. Edentates were far more numerous and varied in the 

 Santa Cruz than in any of the preceding stages. Tree-sloths 

 and anteaters have both been reported, but the evidence is 

 insufficient, though there can be little doubt that these sub- 

 orders had begun their separate existence in some part of 

 South America other than Patagonia. The three families of 

 tground-sloths were already distinguishable, though much less 

 clearly separated than they afterwards became ; none of them 

 were large animals, smaller even than some of the Deseado 

 species and veritable pygmies in comparison with the giants 

 of the Pliocene and Pleistocene. The fglyptodonts were 

 likewise far smaller than their Pliocene and Pleistocene suc- 

 cessors and in several respects more primitive, approximating 

 the armadillos more closely ; nor was there any such variety 

 of forms as in the later stages. The armadillos were extremely 

 numerous and varied ; they all belonged to extinct genera 

 and most of them apparently have no descendants at the 

 present day. The tropical forests of Brazil and the Guianas 

 must then, as now, have swarmed with mammals which did 

 not extend their range to Patagonia and of which we conse- 

 quently have no record. No doubt, it was in these forests 

 that the ancestors of most modern armadillos, as well as of the 

 tree-sloths and anteaters, lived in Miocene times. 



Pliocene edentates were of the same suborders as those of 

 the Santa Cruz, but far larger in size. Most of them are known 

 only from very incomplete specimens, but the Pleistocene has 

 yielded an enormous mass of beautifully preserved material. 

 Of the tree-sloths and anteaters, only questionable remains 

 have been found. That these tropical and forest-loving ani- 

 mals should not have occurred in the open Pampas of Argen- 

 tina is not surprising, but it is difficult to account for their 

 absence from the extremely rich cave-faunas of Brazil. Nearly 

 all the existing genera of armadillos have been obtained, and 

 with these were associated several extinct genera, some of 

 them {'\Chlamydotherium, ]Eutatus) relatively huge, as large 



