IDENTIFICATION OF AN UNKNOWN CARNIVORAN HUMERUS FROM THE MAMMOTH SITE, OF HOT SPRINGS, SOUTH DAKOTA

In 2003, an incomplete humerus was excavated from the Mammoth Site, a Pleistocene sinkhole in Hot Springs, South Dakota. Consisting only of a partial shaft and distal end, this humerus was initially identified as an unspecified large carnivoran. The shape, size, and morphological characters of the bone indicate that it belongs to either an American lion (Panthera atrox) or a giant short-faced bear (Arctodus simus). Measurements were taken on the humerus (MS03021) and compared to those of P. atrox and A. simus from the La Brea Tar Pits in Los Angeles, California. Morphometic and statistical analyses were conducted by constructing bivariate plots of the humeri measurements. The majority of these ratios are in-line with A. simus, and outside the range of P. atrox. Thus, MS03021, the unknown Mammoth Site humerus, is here referred to an A. simus individual. It is quite possible that this represents an additional element of the partial A. simus skeleton previously known from the site.