GIANT SLOTHS AND ARMADILLOS 289 



cause, or causes, led to the extermination of the giant sloths and 

 armadillos is still a matter of speculation. One writer suggests 

 an explanation that seems to deserve consideration. The southern 

 parts of this great continent are even now subject to long- 

 continued droughts, sometimes lasting for three years in succes- 

 sion, and bringing great destruction to cattle. In fact, the 

 discoveries related above were rendered possible by several 

 successive dry seasons. It is argued that the upright position 

 of most of the skeletons found in situ seems to suggest that the 

 creatures must have been mired in adhesive mud sufficiently firm 



FIG. 109. Skeleton of Scelidotherium. (After Capellini.) 



to uphold the ponderous bones after the flesh had decayed. A 

 long drought would bring the creatures from the drained and 

 parched country to the rivers, reduced by want of rain to slender 

 streams running between extensive mud-banks ; and it is possible 

 that, in their anxious efforts to reach the water, they may have 

 only sunk deeper and deeper in the mud until they were engulfed. 

 This idea is strengthened by information supplied to Mr. Darwin 

 when in these parts (recorded in his Journal). An eye-witness 

 told him that during the gran seco, or great drought, the cattle in 

 herds of thousands rushed into the Parana, and, being exhausted 



u 



