1 8 A Remarkable Ground Sloth 



Plant hairs, of two or three types, are abundant. The twigs and roots are of all ages from very 

 young to at least three or four years. They tend to be crooked and branch freely. 



Mingled with the remains is quartz sand in small amount. (The greatest care was taken to 

 make certain that this sand was present normally in the center of the food ball and had not been 

 introduced.) 



The seed coats of a few very small seeds were present. No evidence of leaves could be 

 found. No spines or thorns occur, and no heavy epidermal cells. 



Digestion has removed from the twigs and roots all soft parts. The cortex, phloem, and the 

 pith have to a large extent been removed. 



The plants which make up the food ball are angiosperms and seem to be of the "sagebrush" 

 type. They are freely branching shrubby types, in which the twigs were very slender. Appar- 

 ently they were low, and the animal in browsing pulled them up at times by the roots and con- 

 sumed the entire plant. The presence of frequent and even large roots can hardly be accounted 

 for otherwise. The presence of sand can also be explained in this manner, though doubtless sand 

 would occur on the twigs in a desert region. 



The absence of leaf remains is puzzling. The plants may have been of leafless type, or have 

 been without leaves when eaten. The abundance of very young twigs, however, suggests the 

 growing season, and young foliage would doubtless be completely destroyed (so far as recogni- 

 tion goes) by digestion. 



There are no remains suggesting fleshy or cactus-like types. 



The material is all dicotyledonous and seems to belong largely or wholly to one or two 

 o-enera. The wood structure, general anatomy, and hairs suggest that these genera may belong 

 in the Compositae. 



The few seed coats found, however, appear as though more likely to belong to the Cheno- 

 podiaceae. Further studies are necessary to determine even approximately the identity of these 

 plants. 



In summary : The sloth apparently was feeding upon low-growing, hairy, desert-scrub vege- 

 tation, such as at present grows in the southwestern United States. The plants appear to have 

 been browsed coarsely, being cut into short pieces, often being pulled up by the roots and eaten 

 entire. The stems were not crushed to appreciable degree. The fact that a large part of the twigs 

 have less than one season's growth of wood suggests that the meal was made during the grow- 

 ing season of the plant. All evidence of the nature of the leaves has been destroyed by digestion. 

 The digestive process has removed nearly all of the cellulosic tissues, and it is evident that 

 the "food ball" is a coprolite. 



This would seem to imply as little climatic and vegetative change as topographic. 

 The fact that the sloth ate roots as well as twigs shows that the inference that the claws 

 were used for digging is doubtless correct. Tree sloths eat only the leaves and the 

 three-toed one but two species of plant, the pumpwood, Cecrofia falmata, and wild 

 plum, Sfondias lutea (Beebe, 1926). Our animal was evidently less particular and 

 lived on such sustenance as the region afforded, except the cacti. 



