Mortality Profiles of Mammuthus imperator (Leidy) Sheridan County, Nebraska

Abstract

Mortality profiles of Mammuthus imperator (Leidy) were derived from samples of isolated and socketed teeth recovered from the Rushville (Sh-3) and Gordon (Sh-5) Quarries of Sheridan County, Nebraska. The Sh-3 mortality profile (MNI = 11) is dominated by adult and old individuals and closely corresponds to selective mortality of Loxodonta africana after extended periods of drought. The Sh-5 mortality profile (MNI = 7) corresponds to mortality profiles that reproduce a stable age distribution of East African L. americana, and time-averaged assemblages and mass death events of other North American mammoth samples. Recent advances in the reconstruction of mortality profiles (see Caughley [1966] for review) of the African elephant (Millar and Zammuto, 1983; Conybeare and Haynes, 1984; Haynes, 1987) have provided valuable insights into the life history and evolution of their partial ecologic analogs, the Pleistocene mammoths (Olivier, 1982). To date, mortality profile-based demographic and paleoecologic studies of North American mammoths (Mammuthus) have focused on populations of late Pleistocene M. columbi associated with the Clovis culture (see Fisher [1984] and Haynes [1987] for examples). A point of controversy in the mammoth/Clovis association is the role of man as a mammoth hunter, because recent studies of East African elephant (Loxodonta) populations have shown that drought induces mortality profiles similar to those of proboscideans hunted by late Pleistocene man (Haynes, 1987). By studying the population dynamics of mammoths from the middle and early Pleistocene (before man's arrival in North America) we should be better able to evaluate culturally-derived mammoth samples. Such work will also provide a better understanding of the evolution and paleoecology of Pleistocene proboscideans in general. We studied two samples of socketed and unsocketed partial and complete Mammuthus teeth from the Middle Pleistocene Rushville and Gordon Quarries (University of Nebraska State Museum [UNSM] localities Sh-3 and ShThis content downloaded from 207.46.13.193 on Thu, 08 Sep 2016 04:35:12 UTC All use subject to http://about.jstor.org/terms VOLUME 96, NUMBERS 3-4 197