Late Holocene (Little Ice Age Interval) Microvertebrates from Mackinac County, Michigan‪.‬

ABSTRACT Microvertebrate remains from a dolomitic fissure in the Middle Silurian Engadine Dolomite, Mackinac County, Michigan, represent at least 9 species of Late Holocene (Little Ice Age Interval) vertebrates. These species include Bufo americanus and Pseudacris crucifer (a toad and a frog), Blarina brevicauda and Sorex cinereus (shrews), Myotis cf. Myotis septentrionalis (a bat), Peromyscus maniculatus or Peromyscus leucopus (mice), and Clethrionomys gapperi, Microtus pennsylvanicus, and Synaptomys cf. Synaptomys borealis (voles). All of these currently live in Mackinac County except for the Northern Vole (Synaptomys cf. S. borealis), which occurs in boreal habitats well north of Lake Superior. If the identification of the Northern Vole is correct, the temperature at the time of the accumulation of the bones was probably cooler than at present, and there was probably a greater percentage of coniferous trees in the area. Wetlands must have been present nearby to support the aquatic larvae of the toad and the frog. Wetlands currently lie within a few hundred meters of the site.