Which of the following animals is considered part of Michigan's prehistoric fauna?

The mastodon is recognized as part of Michigan's prehistoric fauna due to its presence in North America during the Pleistocene Epoch, which lasted until about 10,000 years ago. Fossil evidence indicates that mastodons roamed the region that is now Michigan, along with other megafauna, and their remains have been discovered in various locations throughout the state. These large, elephant-like creatures were part of a unique ecosystem that existed before the arrival of humans and were well adapted to the colder climate of the ice age. Their presence in the state's fossil record highlights an important aspect of Michigan's geological and ecological history, capturing interest in the state's prehistoric biodiversity.

In contrast, the grizzly bear, elk, and cougar are species that are currently or were historically present in Michigan but do not fit the definition of prehistoric fauna in the same way mastodons do. These animals have not existed in the region for as long as the mastodon, which existed thousands of years ago before the state took on its current ecological form.