Mastodon

Mastodon — Mastodons or Mastodonts are members of the extinct genus Mammut of the order Proboscidea and form the family Mammutidae; they resembled, but were distinct from, the woolly mammoth which belongs to the family Elephantidae. Mastodons were browsers while mammoths were grazers.

Mastodons are thought to have first appeared almost four million years ago. They were native to both Eurasia and North America, but died out in Eurasia approximately three million years ago. They disappeared from North America about 10,000 years ago, at the same time as most other Pleistocene megafauna.

Though their habitat spanned a large territory, mastodons were most common in the Ice age spruce forests of the eastern United States, as well as in warmer lowland environments.Their remains have been found as far as 300 kilometers offshore in the northeastern United States, in areas that were dry land during the low sea level stand of the last ice age.Mastodon fossils have been found in South America, on the Olympic Peninsula of Washington state, USA, in Kentucky (particularly noteworthy are early finds in what is now Big Bone Lick State Park), in Stewiack, Nova Scotia, Canada, in Richland County, Wisconsin, and north of Fort Wayne, Indiana, USA.

While mastodons were furry like woolly mammoths, and similar in height at roughly three meters at the shoulder, the resemblance was superficial. They differed from mammoths primarily in the blunt, conical shape of their teeth , which were more suited to chewing leaves than the high-crowned teeth mammoths used for grazing; the name mastodon (or mastodont) means mastoid teeth, and is also an obsolete name for their genus. Their skulls were larger and flatter than those of mammoths, while their skeleton was stockier and more robust.Mastodons also seem to have lacked the undercoat characteristic of mammoths.

The tusks of the mastodon sometimes exceeded five meters in length, and were nearly horizontal, in contrast with the more curved mammoth tusks.Young males had vestigial lower tusks that were lost in adulthood. However it has been proven that female mastodons had lower pairs of tusks. The tusks were probably used to break branches and twigs although some evidence suggests males may have used them in mating challenges; one tusk is often shorter than the other, suggesting that, like humans, mastodons may have had laterality. Examination of fossilized tusks revealed a series of regularly spaced shallow pits on the underside of the tusks. Microscopic examination showed damage to the dentin under the pits. It is theorized that the damage was caused when the males were fighting over mating rights. The curved shape of the tusks would have forced them downward with each blow, causing damage to the newly forming ivory at the base of the tusk. The regularity of the damage in the growth patterns of the tusks indicates that this was an annual occurrence, probably occurring during the spring and early summer.

The meat of mastodons was a food source for early humans. Paleontologists are still trying to determine what role, if any, the early human settlers of North America played in the extinction of the mastodon.

Recent studies by scientists in Ohio and New York concluded that tuberculosis may have been partly responsible for the extinction of the Mastodon 10,000 years ago.

In September 2007, Mark Holley, an underwater archeologist 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 high x 5 feet 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.