At http://phys.org/news/2013-11-ancient-giant-sloth-bones-humans.html … a paper in 'Proceedings of the Royal Society B: Biological Sciences' concerns an investigation in Uruguay at a bone bed.
Humans are thought to have entered the Americas after 16,000 years ago (having gone up a bit from the strictuly Clovis scenario) but a little while ago a team of excavators in Brazil came across cave paintings and ceramics that have been dated 30,000 years ago – which is rather upsetting as far as mainstream is concerned. Now we have a claimed link between sloth bones and humans – presuming hunting activity. There are some 1000 individual bones in the bed from 27 individual animals, most of which are giant sloths. Some of the bones seem to have deep slash marks, the sort of thing one might see if stone tools had been used to butcher the meat. The inference is that this was a kill site – and the blurb is that the bones have been dated around 30,000 years ago.
Interestingly, they are saying that to reach Uruguay, humans would have crossed the South Atlantic, using the prevailing winds, and coming from the direction of Africa. On the other hand, assuming megafauna became extinct due to human hunting activity may be what is driving this story. We may note megafauna died out in other parts of the world not too far in time from 30,000 years ago – which might be just a coincidence. The biggest problem for the interpretation is that no certain stone tool has been found – only one that vaguely resembles a human worked piece of stone.