Mastodons (Mammut americanum) and woolly mammoth (Mammuthus primigenius) were unrelated large elephant-like creatures that roamed Illinois until about 13,000 years ago.The wooly mammoth, more equipped to handle the cold, seems to have navigated the northernmost territories just at the southern edge of the retreating Laurentide ice sheet, while the more temperately inclined mastodons are believed to have lived well south of the land where Lake Forest and Lake Bluff are now.Mastodons grazed in the flat plains of southern Illinois, where archeologists have uncovered numerous fossils. The mammoths were more likely to dine on the shrubs and trees that thrived in the northern region of the state.While their fossils are rarer, evidence of the mastodons have been found in the Volo Bog and in Kenosha. Although several post-glacier species are extinct, including both the mammoths and mastodons, many of the species that lived side by side with them 10,000 years ago are still with us, including white-tailed deer, bald eagles, and bobcats.
