Paleoamerican exploitation of extinct megafauna revealed through immunological blood residue and microwear analysis, North and South Carolina, USA.

Previous immunological studies in the eastern USA have failed to establish a direct connection between Paleoamericans and extinct megafauna species. The lack of physical evidence for the presence of extinct megafauna begs the question, did early Paleoamericans regularly hunt or scavenge these animals, or were some megafauna already extinct? In this study of 120 Paleoamerican stone tools from across North and South Carolina, we investigate this question using crossover immunoelectrophoresis (CIEP). We find immunological support for the exploitation of extant and extinct megafauna, including Proboscidea, Equidae, and Bovidae (possibly Bison antiquus), on Clovis points and scrapers, as well as possible early Paleoamerican Haw River points. Post-Clovis points tested positive for Equidae and Bovidae but not Proboscidea. Microwear results are consistent with projectile usage, butchery, fresh- and dry hide scraping, the use of ochre-coated dry hides for hafting, and dry hide sheath wear. This study represents the first direct evidence of the exploitation of extinct megafauna by Clovis and other Paleoamerican cultures in the Carolinas and more broadly, across the eastern United States, where there is generally poor to non-existent faunal preservation. Future CIEP analysis of stone tools may provide evidence on the timing and demography of megafaunal collapse leading to eventual extinction.

Atomic force microscopy of microwear traces on Mousterian tools from Myshtylagty Lagat (Weasel Cave), Russia.

Since durable technology emerged between 3.4 and 3.2 million years ago, stone tools served as a major material means that hominins used to survive. Determining how different lithic tools functioned is a principal question in human evolution. The main experimentally based approach to the functional study of lithic technology uses stereo and incident-light microscopy, and is known as the Keeley Method. Although this method has demonstrated success in linking the morphology of microwear traces on flint tools to the function of the tool, there is no agreed upon model of how these microwear polishes form. At the same time, the characterization of these polishes has been a largely qualitative process. Herein, we use the atomic force microscope (AFM) to scan microwear traces on Middle Palaeolithic (Mousterian) tools from Weasel Cave, Russia to show quantitative data and small scale features of microwear polishes interpreted (using the Keeley Method) as due to contact with meat, fresh hide, dry hide, bone, wood, and hafting. These results follow those of to the previous AFM study on the experimental tools, namely that the meat and dry hide polishes are the least developed polishes with smaller changes in roughness and that the bone polish and wood polishes are more highly developed polishes and exhibit larger changes in roughness.