26 Şubat 2013 Salı

Michigan State Fossil

Michigan State Fossil

American Mastodon (common name) 
Mammut americanum 
(scientific name)
The longest surviving member of the mastodons, the American mastodon is a member of the extinct family Mammutidae, which originated approximately 30 to 35 million years ago in North Africa.Mammut americanum is also a member of the order Proboscidea, which includes mammoths and modern elephants.
American mastodons lived in present-day North and Central America from the Miocene through the Pleistocene epochs of the Quaternary and Tertiary periods, since about 3.5 million years ago. The mastodon’s extinction date is generally accepted as approximately 10,000 years ago, but 5,000-year-old fossils have been reported in Michigan and Utah.
Many discoveries of fossilized mastodon bones, teeth, and tusks have been reported across the United States, including over 250 in Michigan alone, mainly in the southern part of the state. One of the most complete mastodon skeletons ever found was discovered near Owosso, Michigan, and is now on display at the University of Michigan’s Museum of Natural History. The longest and most intact trail of mastodon footprints ever discovered is near Ann Arbor, Michigan.
A Washtenaw Community College professor and his students, together with a Slauson Middle School class, led a campaign for an official state fossil for Michigan. On April 8, 2002, the Michigan legislature passed a bill designating Mammut americanum the state’s official fossil.
The word "mastodon" means "nipple tooth," referring to the unique shape of the animal’s molar teeth. The word comes from the Greek words μαστός (mastos), meaning "breast," and δόντι (donti), meaning "tooth."
This extinct mammal stood about seven to 10 feet (2.1 to 3.1 m) high at the shoulder. Its long, slightly curved tusks were sometimes more than 16 feet (5 m) in length. Like modern elephants, the mastodon had a long, flexible trunk. Its coat of shaggy, dark brown fur made it appear much like a woolly mammoth, a distant relative and contemporary. Mastodons, however, were somewhat smaller, lacked the high-domed head woolly mammoths possessed, and were about 20 million years older than mammoths. The American mastodon was normally about 15 feet (4.5 m) long and weighed approximately 8,000 to 12,000 pounds (3,600 to 5,500 kg).
Mastodons were herbivores, feeding chiefly on shrubs, conifers, grasses, and swamp plants. They were widespread, living in open, swampy forests and wet woodlands from present-day Alaska to possibly as far south as Honduras. Mastodons are distinguished from related mammoths mainly by their molar teeth, which had cone-shaped cusps covered with enamel. These specialized teeth aided the mastodon in clipping and crushing twigs and leaves.
The American mastodon, like the woolly mammoth and many other large mammals of present-day North America, is generally considered to have gone extinct approximately 10,000 years ago, at about the end of the last ice age. Exactly what caused the mass extinction of large mammals during the Pleistocene epoch remains unclear. Paleoindians hunted mastodons, white-tailed deer, and smaller animals, and human hunting is a possible explanation for the mass extinction. Global climate change, contraction of the spruce forests inhabited by these prehistoric mammals, disease, or possibly a mixture of all of these factors, may have contributed to the mastodon’s extinction.
In 1705, a tooth and other mastodon fragments were discovered in the Hudson River Valley in New York State. This is considered the first European reporting of a mastodon fossil.
In 1979, archaeological and paleontological history was made at the Mastodon State Historic Site in Imperial, Missouri, when the first evidence was found of the coexistence of humans and mastodons in North America (their coexistence in the Old World had already been established). Scientists excavated a stone spear point made by hunters of the Clovis culture (who existed approximately 10,000 to 14,000 years ago), which was found with mastodon bones. This site also contains the Kimmswick Bone Bed, one of the most extensive Pleistocene ice age deposits in the country.

Click to enlarge an image
State Prehistoric Creature
Artist Rendering of American Mastodon
State Prehistoric Creature
American Mastodon Skeleton
State Prehistoric Creature
Exhuming the First American Mastodon by C.W. Peale

Species:M. americanum
Author: World Trade Press

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