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Monday, March 22, 2010

Paisley Cave Pre-Clovis

The Winter 2009/2010 edition of American Archaeology has an update on
Dennis Jenkins work at Paisley Cave, where Jenkin's team found human
coprolites that have been dated as Pre-Clovis, 1000 years older than
existing Clovis artifacts, and matching the Pre-Clovis dates at Monte
Verde in Chile. There were doubters in the archaeological community
when the data was announced. Jenkins proceeded to work on his finds
since then to satisfy the doubters that his dates are correct.


Jenkins first took DNA samples from all 67 students, site visitors and
researchers to make sure their DNA did not contaminate the coprolite
DNA, and the data shows there is no contamination from them. The
coprolites were tested at two different locations, in Florida and
Oxford, by using accelerator mass spectrometry and the dates at both
labs were the same, the coprolites are 14,300 years old.


Leading critics said that burrowing animals in the cave could have
upset the stratigraphy and that the obsidian hydration dates that
Jenkins got to match the radiocarbon dates are often not reliable. One
group of critics felt that the coprolites had every indication of
being produced by herbivores. Jenkins pointed out that there are 161
species of edible plants in the area and thus, human feces could look
like an herbivore's. And, to close that argument, Jenkins tests showed
that there was no herbivore DNA found in the coprolites. One critic
pointed out that other artifacts in association with the coprolites
had not been found.


Jenkins and his team carried out an extensive field season in 2009.
Many obsidian and chert flakes were found and a few stone tools. A
tool made from a bison horn was found and a bone tool with teeth along
the edge dated to 14,000 years ago. It could be a mammoth bone tool.
And those who had doubts about a good stratigraphy went to the site in
2009 and came back satisfied that the stratigraphy had not been
disturbed after doing extensive research. 900 human coprolites have
now been unearthed. These have all been sent for testing to various
labs around the world. A twig of sagebrush associated with human
artifacts has been tested at 14,500 years old. In November, Jenkin's
team found a scraper tool that was dated to 14,230 years ago, thus
making it the oldest tool ever found in the Americas.


Here is the story I posted on that discovery;


November 5, 2009
Oldest Tool in the Americas Uncovered


In a very important report in Nature Magazine, Dennis Jenkins, the
archaeologist who found the pre-Clovis human coprolites dated to
14,000-14,270 years old in Paisley Cave in Oregon, now claims to have
found the oldest human artifact ever found in the Americas--a scraper
like tool that dates back to 14,230 years ago. The date was calculated
by way of sediment and radiocarbon dating. The tool was found in a
rock shelter in the caves near Paisley, Oregon. There were some
criticisms of the dating of the coprolites because no human artifacts
were found with them. This discovery of a tool strengthens the
veracity of the earlier claim.


DNAindia has the story here;
NEW (11/09); DNAindia.com; Oldest American Artifact Unearthed Dates
Back to 14,230 Years


And the original story of the Paisley Cave discovery is here;


April 2, 2008


Oldest Biological Evidence of First Americans Found in Coprolites in
Oregon Cave


Archaeologists in Oregon have found fossilized human feces that appear
to be the oldest biological evidence of humans in North America. The
feces or coprolites in archaeological terms date back to 12,500 BCE,
pre-dating the Clovis people by 1000 years. DNA analysis of the
coprolites show the folks who lived in a cave in Oregon at 12,500 BCE
are closely related to modern Native Americans and come from Eastern
Asia. The coprolites were uncovered at Paisley Caves, 220 miles from
Portland.
There is some controversy in the findings since there were traces of
wolves, coyotes and foxes found in the coprolites as well meaning that
there could be some question about the actual age of the human DNA in
the coprolites.

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