Pre-Clovis archaeological sites of the Americas 2: Arroyo del Vizcaíno, Uruguay

A very interesting paper about a Giant Ground Sloth kill site came out at the beginning of last year:

Arroyo del Vizcaíno, Uruguay

Farima et. al. 2014
Arroyo del Vizcaíno, Uruguay: a fossil-rich 30-ka-old megafaunal locality with cut-marked bones Proc. R. Soc. B 7 January 2014vol. 281 no. 1774 20132211
doi: 10.1098/rspb.2013.2211

Abstract
The Arroyo del Vizcaíno site near Sauce, Uruguay has already yielded over 1000 bones belonging to at least 27 individuals, mostly of the giant slothLestodon. 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.

The site is here:

The key finding are these:

 

·         Based on nine samples of bone collagen and wood the site age is between 27 ± 0.45 and 30.1 ± 0.6 14C ka, their pooled average is 29 ± 0.106 14C ka.

·         Maximum age of the site was 32.298ka

·         94% of the bones collected were from the giant ground sloth Lestodon armatus and were almost all from adults. This mortality profile is unlike those found in either attritionally, catastrophically or accidentally accumulated assemblages.

·         Furthermore, the age profile of the ground sloth bones collected is similar to that seen in kill sites, in which a selection of the strongest individuals by human hunters with long-distance weaponry and cooperative ambush strategies is implied.

·         In other words humans slaughtered these giant ground sloths.

 

To get an idea of the tasks these Paleoamericans were taking on killing these Giant Ground Sloths, I have adapted one the figures from the paper to show the relative sizes of the tallest human in South America at that time (1.8m).

Comparison of Giant Ground Sloth, Lestodon armatus (c. 4.6m in length as shown by double arrow) with Paleoindian of c 1.8m height. Adapted from Farina et al 2014.

Figure 3.  Original text read: (b) percentage of minimum anatomical units of ground sloth bones.

As proof of this the authors carried out numerous microscopic examinations of the bones for signs of cut marks indicative of human butchering.
 
They provide some really clear examples:

Original caption from Farina et al 2014:
Bone surface modifications: (a) rib CAV 451; (b) detail of the proximal region; (c) detail of the cut marks: (d) three-dimensional reconstruction of the boxed mark indicated in (c), indicating where sections (i), (ii) and (iii) were taken (section profiles show the two slopes and unaffected bone surface); (e) portion of that cut mark displaying microstriations (arrow) preserved at the base of the groove (right), and parallel set of microstriations (arrow) preserved on a cut mark in CAV 453 showing a V-shaped section (left); (f) lithic element with features characteristic of a scraper, showing an area (*) that differentially reflects the incidental light; (g) SEM photography showing micropolish in area *.


From this exemplary paper, I cannot other than conclude that man lived and hunted Giant Ground Sloth in Uruguay around thirty thousand years ago.
 
This site is an interesting one being set on the east coast of South America.
 
John Hawks theorises at some length about the peopling of the Americas in his review of the Tom Dillehay’s latest Monte Verde paper (See here: http://johnhawks.net/weblog/reviews/archaeology/america/dillehay-monte-verde-2015.html )

“There is a school of thought that population growth should have been rapid once humans entered the virgin landscape of the Americas. With sufficiently rapid growth, the earliest signs of habitation should have been rapidly followed by continent-wide evidence of human populations. By this logic, if people first arrived more than 18,000 years ago, then we should find abundant evidence of them long before 16,000 years ago throughout the Americas.

 
But there may be a problem with the assumption of rapid growth. It assumes that people could rapidly change their strategies to spread into the very different ecologies of inland North and South America.
 
Maybe it wasn’t so easy for them to develop the technical and organizational innovations necessary to move into those continental ecosystems.
 
Sure, humans may have spread rapidly within one relatively uniform environment. Moving down the west coast of the Americas, using coastal resources, may have been such a relatively uniform environment. That’s the proposal that Jon Erlandson and colleagues call the “kelp highway” hypothesis. The idea is that kelp forest ecosystems in the coastal waters of northeastern Asia and North and South America are highly productive habitats. Once people had the ability to move within the coastal waters, they would have had a very easy time hopping among those coastal kelp forests.””
 
This statement is based on several assumptions.

Firstly, that abundant sites of great age have NOT been found in North or South America. That simply isn’t the case as I began to show in my previous post and intend to detail further in a series of posts on Pre-Clovis archaeological sites of the Americas in the coming months.

 
The second assumption follows from the first, it is that “as there are very few sites (which we’ll quietly ignore) in the Americas pre-dating Monte Verde we must formulate a theory that shows how Monte Verde was populated 18000ya just after the last glacial Maxima… “Ah..! I’ve got it they must have come down the west coast in boats!””
 
As Monte Verde is far older than the 18000BP currently assigned to it, and likely dates to 33000 BP, (Dillehay 1997 and 1998) John Hawks should be formulating a theory of where and when Humans REALLY entered the Americas.
 
How John Hawks would account for the Arroyo del Vizcaino site, which would involve thousands of extra kilometres of boat travel and the rounding of Cape Horn or an arduous crossing of the Andes is a really good question. Could this be why this paper has NOT been on his blog?
 
Simply ignoring the earlier dates, seems to me very much like the Clovis-first situation of a few years ago. I think older anthropologists and archaeologists like John Hawks still have an ingrained propensity to resist older dates for sites in the Americas. Some might call that a form of bias.

My best guess for the peopling of the Americas, is both overland very early and in boats later!
 
References
Dillehay TD. Monte Verde: A Late Pleistocene Settlement in Chile. Volume II: The Archaeological Context. Washington, D.C.: Smithsonian Institution Press; 1997.