Recent Discoveries of Fossil Vertebrates in the Lower Peninsula of Michigan
Holman, J. Alan, Fisher, Daniel C., Kapp, Ronald O., Michigan Academician
Editor's Comments. J. A. Holman is presently Curator Emeritus of Vertebrate Paleontology at the Michigan State University Museum and Daniel O. Fisher is a professor and curator of paleontology in the University of Michigan Museum of Paleontology. This paper (produced because of the encouragement of Ronald O. Kapp) provided an update on records of mastodont and mammoth localities (as well as other Pleistocene vertebrates) and, in doing so, posed several questions, including (1) Why were proboscidean sites in the state so abundant for such a short period of time (12,000 to 10,000 years ago), while other vertebrates were apparently so uncommon? (2) Why did the proboscideans and other mammals become extinct so suddenly? and (3) What was the impact of human hunters on the flora and fauna of Michigan. The "Human Interaction" section in the paper introduced some of D. Fisher's evidence for the butchery of mastodonts by human hunters in Michigan. Fisher soon provided other valuable information about the taphonomy and biology of mastodonts, as well as their human interactions, in a flurry of publications in other journals.
Since the last detailed publication on the Pleistocene vertebrates of Michigan (Wilson 1967), much new information has accumulated: new sites have been found; ranges have been extended; C-14 dates have been obtained; vertebrates have for the first time been identified from a Wisconsinan interstadial interval; and butchering of extinct proboscideans by humans has been demonstrated at several localities. Thus, we believe that the time has come to consolidate this new information in a single location.
Several modern workers have gone beyond the stage of merely salvaging fossil vertebrates, and several of these works are cited here. Nevertheless, compelling problems are still with us such as (1) why proboscidean sites are so abundant from such a short period of time (12,000-10,000 years before the present [hereafter B.P.]), while other vertebrates were apparently so uncommon; (2) why the proboscideans and other large mammals became so suddenly extinct; and (3) what was the impact of the Paleo-Indian population on the flora and fauna of Michigan. We hope that this paper will stimulate additional interest in Michigan Pleistocene vertebrates so that some of these problems may be solved. The following two sections, Paleoecology and Human Interactions, are discussions growing out of consideration of the new records in the Systematic Paleontology section.
This section deals with considerations of taphonomy and faunal diversity (Holman) and with the late Pleistocene vegetation and climate (Kapp).
Taphonomy and faunal diversity. -- Seventy-four new records of Michigan late Pleistocene vertebrates are assembled in the Systematic Paleontology section of this paper, superseding the summary of Wilson (1967). A large number of the new records of Michigan late Pleistocene vertebrates are proboscideans (57 of 74 = 77.0%); and in cases where such information was recorded, most of these huge animals came from kettle-like depressions, very often associated with muck or peat deposits. It has previously been assumed (Holman 1975) that these animals became trapped and drowned in these features.
Of the 52 proboscideans that were identified to the specific level 42 (80.8%) were mastodonts, and 10 (19.2%) were mammoths. Other vertebrates reported here include two fishes, one amphibian, one bird, two giant beavers, one muskrat, two meadow voles, one black bear, one peccary, one moose, two Scott's moose, and two whitetailed deer. In a Michigan late Pleistocene vertebrate site, it is usual to find one large animal, sometimes associated with the remains of another species or two. Holman has searched very carefully for microvertebrate remains at many of these sites, and only in one case (Adams Site in Livingston County) has he found small vertebrate remains, representing two fishes and one meadow vole. …