INTERPOLATED PALAEOTEMPERATURES FOR LATEST PLEISTOCENE TO EARLY HOLOCENE MAMMOTH FINDS FROM WESTERN NORTH AMERICA

Recent overall acceptance by the archaeological community of the validity of the Monte Verde archaeological assemblage and it's early ¹⁴C chronology (Meltzer et al. 1997) has led to a new awakening in several lines of late Pleistocene palaeoenvironmental and archeological research in North America. The results from Monte Verde, coupled with a new assessment of the actual record of late Pleistocene megafaunal extinctions in North America, necessitate abandonment of the 'overkill' model as proposed by Martin (1967) and various co-authors. The three inferential legs of the tripod that support the 'overkill' model can now be shown to be either wrong, inconclusive, or lacking in significant supportive evidence. Clearly the Clovis Culture was not the first to arrive in the Americas, and extensive evidence of association between North American megafauna and Clovis predation remains either elusive and/or insignificant (Grayson and Meltzer 2002). Chronologically the extinction 'event' of the model can now be shown to have been composed of multiple extinctions most likely occurring over a period of no less than 10,000 years (Grayson and Meltzer 2003). The void created by the demise of the 'overkill' model only serves to emphasize our general lack of genus/species specific palaeoenvironmental data for extinct North American megafauna species. In short, it has always proven easier to attack the 'overkill' model, and much harder to produce useful data in support or opposition to the various 'climate- and/or environmental-change' extinction models (Graham and Lundelius 1984; Guthrie 1984). This poster presents the results of nascent research into extracting palaeotemperature data for western North American mammoth sites out of the previously published palaeoclimate model data for this region (Thompson et al. 1994). Seventy-four radiocarbon or culturally dated mammoth finds, ranging in date from the Last Glacial Maximum (LGM) to the early Holocene, are assigned tentative palaeotemperature values based on interpolated data drawn from this model, and the significance of these temperatures for mammoth extirpation from North America is noted.