PALEOINDIAN-MAMMOTH INTERACTIONS AND LATE PLEISTOCENE ENVIRONMENTS IN SOUTHEASTERN WISCONSIN

Human-butchered Mammuthus cf. M. jeffersoni (Jefferson mammoth) skeletons at two localities in Kenosha County, southeastern Wisconsin, predate the accepted Clovis time frame. Excavations at the Schaefer (47Kn252) and Hebior (47Kn265) sites recovered stone tools in direct association with mammoth bones which bear butchering marks. Numerous radiocarbon ages were obtained from purified bone collagen and wood associated with the bones, which date these mammoths to 12,300 - 12,500 14C yr BP. Sediments associated with the bones were analyzed for fossil pollen and plant macrofossils. In addition, a sediment core was collected 100 m downslope of the Schaefer site excavation area for reconstruction of a longer pollen and plant macrofossil record, which is bracketed by ages of 12,900 and 8,900 14C yr BP.

Our data indicate that at c. 12,500 14C yr BP these mammoths were butchered by Paleoindians along the edge of an intermoraine lake. Mammoths are often thought associated with tundra habitats, but the environment we reconstruct was a parkland comprised primarily of Picea (both white and black spruce) and herbaceous plants. Grasses and forbs occupied both upland and lowland (wetland) habitats and the assemblage was comprised of species which exist in this area today. Abies (fir) and deciduous hardwoods, such as Fraxinus nigra (black ash) and Quercus (oak), co-existed with the spruce, but became more widespread after 11,000 14C yr BP when spruce abundance declined. In sum, the late-glacial spruce parkland environment of southeastern Wisconsin supported mammoth populations as well as the Paleoindians which utilized these megafauna for their subsistence.