Mammals of Michigan There are many mammal species in Michigan, and this paper will discuss some of them, in terms of how they have evolved to live in the Michigan area, and how they have evolved to live off the land in the Michigan area. Something of the geological history of Michigan will also be discussed.

We will start with the extinct mammals of the Michigan area: about 12,500 to 11,800 years ago, the Michigan area was covered with boreal forest dominated by spruce trees, and the fauna that was dominant in this area over this period moved here from South of the area. The important mammals of Michigan during this period were: Scott's moose, giant beevers, flat-headed peccaries, woodland muskoxen, mammoths and mastodons. It has been suggested that the mammoths and mastodons, in particular, were drawn to Michigan because of the many salt seeps and the many sources of shallow water, from which they could drink. These mammoths and mastodons may therefore have been migratory in their behavior, and stayed in the Michigan area due to the well-suited surroundings. Around 10,000 years ago, these large mammals became extinct in the Michigan area (in common with their extinction in most of the rest of the world). The reasons for this extinction are unclear, but has been hypothesized to have been caused by: climate change; a drop in the water table, causing a reduction in the amount of available drinking water; human hunters hunting the species to extinction; new diseases, introduced from species immigrating across the Bering Strait.

We will now move on to discuss something of the appearance, behavior, and feeding habits of these extinct Michigan mammals. First, the giant beever. The giant beever, Castoroides ohioensis, was the largest North American rodent during the Ice Age (in the last two million years). They were distant cousins of the modern-day beever, with 15cm-long teeth which had prominently-ridged outer surfaces, with an S-shaped enamel pattern. From fossils of the giant beever, it has been estimated that they had scaly tails up to 65cm long, that was narrow at the end, and therefore well-adapted for swimming (as with the modern-day...

From tracing the fossil record, it is thought that the giant beever was descended from Dipoides, a primitive beever that lived 5 million years ago (during the late Tertiary). It is thought that Dipoides gave rise to Procastoroides which eventually gave rise to the giant beever, Castoroides ohioensis. Studies of tooth enamel, and tooth shape patterns, supports this lineage: Dipoides, Procastoroides, Castoroides.
Giant beevers were found throughout North America during the period of their reign, but were not found outside of North America (information from the Yukon Beringia Interpretive Center notes).

During the period of the last glaciation, giant beevers seem to have flourished around the Michigan area; it is thought they lived in lodges (similar to modern-day beevers) and that these lodges were composed of saplings. A suspected giant beever lodge found near New Knoxsville, Ohio, was 1.2m high and 2.4m in diameter. From analysis of their fossils, giant beevers seem to have preferred swampy regions, as the majority of their fossil remains have been found near to ancient swamps (information from the Yukon Beringia Interpretive Center notes).

Next, we shall discuss the mammoth. Fossil mammoths are known only from the Pleistocene in the Michigan area. Michigan can boast two species of mammoth: the American mastodon and the Jefferson mammoth. Many of the fossil remains of the American mastodon and the Jefferson mammoth have been found in swampy deposits, which suggests that these were the preferred habits of these species throughout their lifetime. This is good for paleontologists, as swampy deposits are excellent sites for the preservation of fossils. Mammoths and mastodons were both huge, elephant-like mammals, with great protruding tusks and long, hairy, orange-colored fur, which covered the entirety of their body, and which is thought to have protected the species from the extremely low temperatures around in the Michigan area at the time in which they lived. It is thought that mammoths and mastodons, in particular, were hunted to extinction following the arrival of humans in the Michigan area, as stone hunting…