Clovis Age Western Stemmed Projectile Points and Human Coprolites at the Paisley Caves

Abstract

The Paisley Caves in Oregon record the oldest directly dated human remains (DNA) in the Western Hemisphere. More than 100 high-precision radiocarbon dates show that deposits containing artifacts and coprolites ranging in age from 12,450 to 2295 (14)C years ago are well stratified. Western Stemmed projectile points were recovered in deposits dated to 11,070 to 11,340 (14)C years ago, a time contemporaneous with or preceding the Clovis technology. There is no evidence of diagnostic Clovis technology at the site. These two distinct technologies were parallel developments, not the product of a unilinear technological evolution. "Blind testing" analysis of coprolites by an independent laboratory confirms the presence of human DNA in specimens of pre-Clovis age. The colonization of the Americas involved multiple technologically divergent, and possibly genetically divergent, founding groups.

Test of Martin’s overkill hypothesis using radiocarbon dates on extinct megafauna

“…Our estimated dates of megafaunal decline from the spacings and binning analyses overlap with the age range for Clovis (36). Various sites have been argued to date considerably earlier than the oldest dates for the Clovis complex, perhaps as early as 15,500 BP (37)(38)(39)(40). If there was a significant human presence in North America before the onset of Clovis, pre-Clovis foragers had no measurable impact on megafaunal populations, despite the fact that they were apparently hunting these species (37,39,40).…”

Did Pre-Clovis People Inhabit the Paisley Caves (and Why Does It Matter)?

“…14,000-14,400 cal yr BP) are intermixed with "Human" coprolites dated between 11,625 and 11,190 14 C yr BP continue to occur upward in the sediments that are capped by a sloping "compact silt lens formed by a brief pooling of water on the cave floor" (Jenkins et al 2012a). One of the WST point fragments was encased within this lens.…”

“…Although Jenkins et al (2012a) assert that "The Paisley Caves rarely experienced wetting events that could transport aDNA into older strata", the silt lens attributed to pooled water is a glaring exception. Indeed, Jenkins et al (2012a: SOM p. 18) suggest that the water that formed this lens may also have saturated a camelid coprolite that was found 12 cm below it; this may account for a date on water-soluble organic matter (11,315+-25 14 C yr BP) that is 900 years younger than the remaining organics (12,215+-30 14 C yr BP) in this coprolite.…”

“…dates for the hearth (Jenkins et al 2012a). Despite intensive efforts to find early cultural items, all of the directly dated artifacts made of organic materials (e.g., cordage and a possible wooden dart fragment) from the deepest strata still date later than 10,550 14 C yr BP and appear to be derived by downward drift from the WST assemblage.…”

“…Poinar et al (2009) noted chronological and stratigraphic problems and suggested that contamination by leaching might account for possibly exogenous human DNA in the coprolites, while Goldberg et al (2009) (who had actually examined and sampled the coprolites) asserted that their morphology was inconsistent with human derivation. Jenkins et al (2012a) report results of meticulous excavations and analyses designed to verify their previous claims. This research was focused particularly on demonstrating that the radiocarbon dates are accurate and the coprolites have not been contaminated by leaching.…”