Ancient giant sloth bones suggest humans were in Americas far earlier than thought

Nov 20, 2013 by Bob Yirka report
Panoramic view and orientation of the bones: (a) the bonebed showing the 1 m grid used to reference collected elements: (b) schematic of the bones to show their orientation. Credit: Proceedings of the Royal Society B: Biological Sciences, doi: 10.1098/rspb.2013.2211

(Phys.org) —A team of Uruguayan researchers working at the Arroyo del Vizcaíno site near Sauce, in Uruguay has found evidence in ancient sloth bones that suggests humans were in the area as far back as 30,000 years ago. The team describes their evidence and findings in a paper they've had published in Proceedings of the Royal Society B: Biological Sciences.

Most scientists today believe that humans populated the Americas approximately 16,000 years ago, and did so by walking across the Bering Strait, which would have been frozen over during that time period. More recent evidence has begun to suggest that humans were living in South America far earlier than that—just last month a team of excavators in Brazil discovered cave paintings and ceramics that have been dated to 30,000 years ago and now, in this new effort, the research team has found more evidence of people living in Uruguay around the same time.

In this new effort, the researchers found over a thousand bones at the Arroyo del Vizcaíno site, (from approximately 27 different animals) most of which once belonged to the now extinct giant sloth. What was most remarkable however, were the deep slash markings on some of the bones—indicative of stone tools. Also interesting was that the bones were all from the remains of large, full grown sloths—all in a single place where they wouldn't have died in other ways such as from falling off a cliff. Taken together, it appears the sloths were killed individually, as needed, and eaten, most likely, by humans as no other known animal could have pulled off such a feat. The team also found a stone that appears to have been fashioned to serve as a scraping tool.

The researchers suggest that if humans were indeed in living in South America as far back as 30,000 years ago, they likely arrived there by floating over from Africa—the prevailing winds would have carried them directly there without the need of paddles or sails. Sloths, they suggest would have been an excellent food source once they arrived—adults would have been up to 15 feet tall and weighed approximately two to four tons, offering enough food for a group of people.

Explore further: 110-million-year-old crustacean holds essential piece to evolutionary puzzle

More information: Arroyo del Vizcaíno, Uruguay: a fossil-rich 30-ka-old megafaunal locality with cut-marked bones, Proceedings of the Royal Society B: Biological Sciences, Published 20 November 2013, DOI: 10.1098/rspb.2013.2211

Abstract
Human–megafauna interaction in the Americas has great scientific and ethical interest because of its implications on Pleistocene extinction. The Arroyo del Vizcaíno site near Sauce, Uruguay has already yielded over 1000 bones belonging to at least 27 individuals, mostly of the giant sloth Lestodon. The assemblage shows some taphonomic features suggestive of human presence, such as a mortality profile dominated by prime adults and little evidence of major fluvial transport. In addition, several bones present deep, asymmetrical, microstriated, sharp and shouldered marks similar to those produced by human stone tools. A few possible lithic elements have also been collected, one of which has the shape of a scraper and micropolish consistent with usage on dry hide. However, the radiocarbon age of the site is unexpectedly old (between 27 and 30 thousand years ago), and thus may be important for understanding the timing of the peopling of America.

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User comments : 7

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philw1776
1.8 / 5 (4) Nov 20, 2013
It took a couple decades for the Clovis First settled science to be overthrown. More evidence is needed here but prepare to have the 1st Americans date back a few tens of thousands of years. Could make the indigenous South American populace the first "African Americans". :)
goracle
1 / 5 (3) Nov 20, 2013
I'll wait for more study of this before shouting anything from the rooftops. There have been some spectacular overreaches before. It is now understood that there is a strong case for the original settlers having come from Asia by small boat along the Pacific coastline earlier than the ice-free corridor would have allowed. Why not the same route much earlier?
Lurker2358
1.1 / 5 (8) Nov 20, 2013
The researchers suggest that if humans were indeed in living in South America as far back as 30,000 years ago, they likely arrived there by floating over from Africa—the prevailing winds would have carried them directly there without the need of paddles or sails.


What about the Viral DNA evidence from graves which shows the ancient Japanese visited South America at least 8,000 years ago?

Remember, the ancient east-asians and polynesians were incredibly good on the seas compared to most of the world at that time. They figured out how to cross oceans directly, while other civilizations were still afraid they'd fall off the edge of the world, or some other stupidity, and stayed within sight of land.

I thought genetic evidence even showed that east-asians and Native Americans were closely related?

I don't want to sound crude, but South Americans have been breeding, for lack of a better term, with hispancis for over 400 years...continued...
Lurker2358
1.1 / 5 (10) Nov 20, 2013
So because of this inter-breeding between the Hispanics and the natives in S. America, your basis of DNA comparisons will be biased toward Western European and African relations, possibly some Arabic relations too, since the Islamists tried to invade Europe on several occasions a few centuries before Columbus' voyage.

So some DNA from all of those groups would be in S. American DNA, but it is not the "source" population. Sorting that out would require much more extensive testing than just a few dozen or hundred samples.
barakn
5 / 5 (5) Nov 20, 2013
So because of this inter-breeding between the Hispanics and the natives in S. America, your basis of DNA comparisons will be biased toward Western European and African relations, possibly some Arabic relations too, since the Islamists tried to invade Europe on several occasions a few centuries before Columbus' voyage.

So some DNA from all of those groups would be in S. American DNA, but it is not the "source" population. Sorting that out would require much more extensive testing than just a few dozen or hundred samples.

Or you could just sequence some pre-Columbian mummies. You really don't invest much thought in what you write, do you.
VendicarE
3 / 5 (4) Nov 20, 2013
Giant Sloth? Isn't that one of Rush Limbaugh's ancestors?
Lurker2358
1 / 5 (4) Nov 21, 2013
Or you could just sequence some pre-Columbian mummies. You really don't invest much thought in what you write, do you.


That's what I was talking about. The Viral DNA I'm referring to came from burial sites, and that virus only affects modern Japanese, therefore there is a relationship.

Apparently you are the one who doesn't give much thought to your posts.

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