American Mastodon - Extinction

Extinction

M. americanum is generally reported as having disappeared from North America about 10,000 years ago, as part of a mass extinction of the Pleistocene megafauna. However, more recent radiocarbon dates have been found, such as 5200 BC in Seneca, Michigan, 5140 BC in Utah, 4150 BC in Washtenaw, Michigan, and 4080 BC in Lapeer, Michigan.

Recent studies indicate that tuberculosis was common in late Pleistocene American mastodons, and it has been suggested that this could have contributed to their extinction 10,000 years ago. However, it is not considered plausible that the disease could have caused the extinction on its own.

Another factor contributing to their eventual extinction in America during the late Pleistocene may have been the presence of Paleo-Indians, who entered the American continent and expanded to relatively large numbers 13,000 years ago. Their hunting caused a gradual attrition of the mastodon and mammoth populations, significant enough that over time the mastodons may have been hunted to extinction. Analysis of tusks of mastodons from the American Great Lakes region over a span of several thousand years prior to their extinction in the area shows a trend of declining age at maturation; this is contrary to what one would expect if they were experiencing stresses from an unfavorable environment, but is consistent with a reduction in intraspecific competition that would result from a population being reduced by human hunting.

In September 2007, Mark Holley, an underwater archaeologist with the Grand Traverse Bay Underwater Preserve Council who teaches at Northwestern Michigan College in Traverse City, Michigan, said that they might have discovered a boulder (3.5 to 4 feet (1.2 m) high by 5 feet (1.5 m) long) with a prehistoric carving in the Grand Traverse Bay of Lake Michigan. The granite rock has markings that resemble a mastodon with a spear in its side. Confirmation that the markings are an ancient petroglyph will require more evidence.