A Report on the Shelton Mastodon Site and a Discussion of the Numbers of Mastodons and Mammoths in Michigan

Article excerpt

Originally published in Michigan Academician Vol. XXI, No. 2 (Spring 1989): 115-32

Editor's Comments. J. Shoshani, formerly a professor at Wayne State University in Detroit, is now associated with the University if Asmara, Asmara, Eritria. An energetic researcher on both fossil and modem proboscideans , Dr. Shoshani supervised multidisciplinary excavations of mastodont sites in southeastern Michigan (e.g., Shoshani et al. 1989). This approach has allowed him to discuss the food web of the the mastodont-dominated community as well as the paleoecology of the associated fauna and flora. This paper provides an update to Holman et al. (1986), but the main contribution of the paper reflects on the 5:1 dominance in Michigan of mastodont fossils over mammoths, and suggests that mastodonts were ecological generalists, better adapted to a diversity of habitats than the mammoth, which was more of a specialist. The author postulates that the more or less treeless habitats which the mammoth required were not common enough to support very large populations in Michigan and contrasts Michigan with the Nebr aska plains where the mammoths outnumbered mastodonts about 8 to 1.

INTRODUCTION

Elephants, mammoths, and mastodons (order Proboscidea) have fascinated mankind since the dawn of prehistory. The first report of the American mastodon (Mammut americanum) in Michigan was during the nineteenth century (Lanman 1839). In the intervening 150 years, people have continued to find bones and teeth of the extinct American mastodon and mammoths (Mammuthus sp.). Most of these finds were bones and tooth fragments, and only very few complete or partially complete specimens were discovered. Presently, there are two mounted skeletons of the American mastodon in Michigan; one, probably a female, is at the Exhibit Museum of the University of Michigan, Ann Arbor (Dorr and Eschman 1970), and the other, probably a male, is at the Highland Lakes Campus of Oakland Community College, Union Lake (Dorr et al. 1982).

The vast majority of these proboscidean materials came from occasional

surface finds reported by farmers or amateur collectors (see for example Dorr and Eschman 1970, and Holman et al. 1986, and Appendix A in this paper). When locations are precisely documented, surface finds provide us with important information about past inhabitants and their paleoecology, but only bones and teeth collected in well-defined strarigraphic context can be dated and associated with particular environmental features.

The two mastodons focused upon here were uncovered at the Shelton Mastodon Site (SMS), a well-documented Michigan locality (Shoshani et al., 1989; Shoshani and Zawiskie, unpublished ins.). Field work at the SMS was carried out during the summer months of 1983-1987, following standard techniques as described byJoukowsky (1980), Kummel and Raup (1965), and Rixon (1976). A detailed account of the findings at this site during the years 1983-1986 appears in Shoshani etal. (1989). In this paper, I shall provide a timely summary of the uncovered fauna and macro flora for the entire excavation period and briefly review the significance of the findings. The mastodons listed in Appendix A (which is an update to Holman et al. 1986), provide the basis for my discussion on the numbers of mammoths and mastodons in Michigan.

THE SHELTON MASTODON SITE

The SMS is located in southeastern Michigan, northern Oakland County (Brandon Township SE 1/4 of SE 1/4 of Section 26, T5N R9E, 82[degrees] 20' W longitude, 42[degrees] 50' N latitude, at an elevation of 317 m (1040 ft.) above sea level (Figure 1). During the Port Bruce Stade, Oakland County was covered with a continental ice sheet; subsequent retreat of the Saginaw and Huron-Erie lobes resulted in the deposition of a portion of the Defiance Morainic System in northern Oakland County approximately 14,500 years ago (Farrand and Eschman 1974; Evenson et al. …