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The timing of the first human migration into the Americas and its relation to the appearance of the Clovis technological complex in North America at about 11,000 to 10,800 radiocarbon years before the present (¹⁴C years B.P.) remains contentious. We establish that humans were present at Paisley 5 Mile Point Caves, in south-central Oregon, by 12,300 ¹⁴C years B.P., through the recovery of human mitochondrial DNA (mtDNA) from coprolites, directly dated by accelerator mass spectrometry. The mtDNA corresponds to Native American founding haplogroups A2 and B2. The dates of the coprolites are >1000 ¹⁴C years earlier than currently accepted dates for the Clovis complex.

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 ¹⁴C years ago are well stratified. Western Stemmed projectile points were recovered in deposits dated to 11,070 to 11,340 ¹⁴C 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.

Waters and Stafford (Reports, 23 February 2007, p. 1122) provided useful information about the age of some Clovis sites but have not definitively established the temporal span of this cultural complex in the Americas. Only a continuing program of radiometric dating and careful stratigraphic correlations can address the lingering ambiguity about the emergence and spread of Clovis culture.

Archaeologists have long subjected Clovis megafauna kill/scavenge sites to the highest level of scrutiny. In 1987, a Columbian mammoth (Mammuthus columbi) was found in spatial association with a small artifact assemblage in Converse County, Wyoming. However, due to the small tool assemblage, limited nature of the excavations, and questions about the security of the association between the artifacts and mammoth remains, the site was never included in summaries of human-killed/scavenged megafauna in North America. Here we present the results of four field seasons of new excavations at the La Prele Mammoth site that confirm the presence of an associated cultural occupation based on geologic context, artifact attributes, spatial distributions, protein residue analysis, and lithic microwear analysis. This new work identified a more extensive cultural occupation including the presence of multiple discrete artifact clusters in close proximity to the mammoth bone bed. This study confirms the presence of a second Clovis mammoth kill/scavenge site in Wyoming and shows the value in revisiting proposed terminal Pleistocene kill/scavenge sites.

The arguments of Poinar et al . neither challenge our conclusions nor would contribute to the verification of our data. We counter their questions about the authenticity of our ancient DNA results and the reliability of the radiocarbon data and stand by the conclusion that our data provide strong evidence of pre-Clovis Native Americans.

With the recent introduction of handheld instruments for field use, laser-induced breakdown spectroscopy (LIBS) is emerging as a practical technology for real-time in situ geochemical analysis in the field. LIBS is a form of optical emission spectroscopy that is simultaneously sensitive to all elements with a single laser shot so that a broadband LIBS spectrum can be considered a diagnostic geochemical fingerprint. Sets of LIBS spectra were collected for seven obsidian centers across north-central California, with data processed using multivariate statistical analysis and pattern recognition techniques. Although all obsidians exhibit similar bulk compositions, different regional obsidian sources were effectively discriminated via partial least squares discriminant analysis. Obsidian artifacts from seven archaeological sites were matched to their putative sources with a high degree of confidence.

The 1960s and 1970s excavations at Owl Cave (10BV30) recovered mammoth bone and Folsom-like points from the same strata, suggesting evidence for a post-Clovis mammoth kill. However, a synthesis of the excavation data was never published, and the locality has since been purged from the roster of sites with human/extinct megafauna associations. Here, we present dates on bone from the oldest stratum, review provenience data, conduct a bone-surface modification study, and present the results of a protein-residue analysis. Our study fails to make the case for mammoth hunting by Folsom peoples. Although two of the point fragments tested positive for horse or elephant protein, recent AMS dates indicate that all of the mammoth remains predate Folsom, and horse remains are absent from the Owl Cave collection. Further, no unambiguously cultural surface modifications were identified on any of the mammoth remains. Given the available data, the Owl Cave deposits are most parsimoniously read as containing a Folsom-age occupation in a buried context, the first of its kind in the desert West, but one nonetheless part of a palimpsest of terminal Pleistocene materials. Durante excavaciones de Owl Cave (10BV30) en Idaho en las décadas de 1960 y 1970 fueron recuperados de los mismos estratos huesos de mamut y puntas de proyectil del estilo Folsom, sugiriendo que se tratara de un yacimiento matanza de mamuts de la era post-Clovis. Sin embargo, nunca se publicó una síntesis de los datos de la excavación y la localidad ha sido removida de la lista de sitios con evidencia de actividad humana asociada con megafauna extinta. Aquí presentamos el fechamiento de muestras de hueso del estrato más antiguo de la cueva, revisamos sus datos de procedencia, realizamos un estudio de la superficie de los huesos, y presentamos los resultados de un análisis de residuos proteicos. Nuestro estudio no logra comprobar la evidencia de cacería de mamut por la cultura Folsom. Aunque en dos de los fragmentos de proyectil se detectaron restos de proteína de caballo o elefante, fechados recientes por AMS indican que todos los restos de mamut preceden el yacimiento Folsom y no hay restos de caballo en la colección de Owl Cave. Además, no se identificó ninguna modificación de superficie de claro origen cultural en los restos de mamut. La interpretación más parsimoniosa de los datos disponibles es que los depósitos de Owl Cave contienen una ocupación de la época Folsom en un contexto enterrado, el primero de este tipo en el desierto del Oeste, pero que sin embargo es parte de un palimpsesto de materiales del Pleistoceno terminal.

We report on a re-analysis of the obsidian from Rose Spring (CA-INY-372), Inyo County, California, based on obsidian hydration dating. The computed projectile point ages for Desert Series, Rose Spring Corner-Notched, Elko, and Humboldt Basal-Notched points fall within the expected range, which gives confidence in the analytic technique. The projectile points are younger than the debitage, even though both points and debitag experienced similar temperature histories, and the age difference is statistically significant at the 95% confidence level. Five of the Rose Spring Corner-Notched points show evidence of having been reworked from earlier points. The debitage age data also show a dependence on depth, but not as strongly as the radiocarbon data, probably due to vertical mixing. Both the mixing and the earlier age for the debitage suggest that tool stone on hand as debitag was salvaged and reutilized for tool manufacture, as a substitute for logistical traveling to gather lithic material from its source in the Coso volcanic field.

Ethnographic accounts of animal pulverization using stone grinding implements have led archaeologists to believe that this same behavior took place in the past. This important subsistence activity can now be confirmed through the immunological analysis of archaeological materials. Small-mammal blood-protein residue has been identified immunologically for the first time on milling equipment from two archaeological sites in southern California. Immunoprotein trace analysis has the potential for a wide range of applications in the study of prehistory.

During the summer of 2006, the authors had the opportunity to visit portions of the extensive flint quarries found associated with Wadi el-Sheikh near El-Minya, Middle Egypt. The subject of little formal study, these impressive quarries extend for several kilometers in the northern portion of the wadi and likely were used since prehistoric times. Initial evidence suggests that these quarries, where millions of flint blades and bifacial knives were produced, were at the height of their production activities during the Pharaonic periods. A cursory technological lithic analysis onsite has allowed for a preliminary interpretation of what appears to have been a common reduction sequence for the production of flint blade-cores used at the quarries. The current model for this flint reduction process is presented here.