Overdone overkill – the archaeological perspective on Tasmanian megafaunal extinctions

The reasons for megafaunal extinction in Australia have been hotly debated for over 30 years without any clear resolution. The proposed causes include human overkill, climate, anthropogenic induced habitat change or a combination of these. Most protagonists of the human overkill model suggest the impact was so swift, occurring within a few thousand years of human occupation of the continent, that archaeological evidence should be rare or non-existent. In Tasmania the presence of extinct megafauna has been known since the early twentieth century (74, 85 and 86) with earlier claims of human overlap being rejected because of poor chronology and equivocal stratigraphic associations. More recent archaeological research has not identified any megafauna from the earliest, exceptionally well-preserved late Pleistocene cultural sites. In 2008 however an argument for human induced megafaunal extinctions was proposed using the direct dates from a small sample of surface bone from two Tasmanian non-human caves and a museum sediment sample from an unknown location in a cave, since destroyed by quarrying (Turney et al., 2008). Turney et al. (2008) supplemented their data with published dates from other Tasmanian caves and open sites to argue for the survival of at least seven megafauna species from the last interglacial to the subsequent glacial stage.     

Late Pleistocene protein residues from the Mahaffy cache,Colorado

This paper reports the analysis of protein residues from tools recovered in a cache within the city limits of Boulder, Colorado, USA. This cache included a total of 83 artifacts, all of which we subjected to cross-over immunoelectrophoresis (CIEP). Four of the 83 produced results, with residues from each of these reacting with antigens from a different taxon: one tool shows evidence of use on sheep, one on bear, one on horse, and one on camel. Varieties of sheep and bear have been present in Colorado throughout human history, but horses and camelids have been in the state either during the Pleistocene or the last 200 years. Several lines of evidence indicate that the cache cannot be recent, and our CIEP results therefore imply that the cache date to the late Pleistocene. Typological aspects of the artifacts in the cache are consistent with artifacts known to be Clovis, and the combination of CIEP and typological data thus indicate that the cache is Clovis as well. These data contribute to an increasing dataset documenting the broad range of animals other than elephants hunted by Clovis groups in North America.