Mastodon

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Mastodon
Fossil range: 4–0 Ma
Pliocene – Recent

Mounted mastodon skeleton, Museum of the Earth .
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Proboscidea
Family: Mammutidae
Hay, 1922
Genus: Mammut
Blumenbach, 1799
Species
  • Mammut americanum
  • Mammut cosoensis
  • Mammut furlongi
  • Mammut matthewi
  • Mammut pentilicus
  • Mammut raki
  • Mammut spenceri

Mastodons or Mastodonts (Greek: μαστός "nipple" and οδούς, "tooth") 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.

Contents

[edit] Habitat

A mastodon.

Mastodons are thought to have first appeared almost four million years ago. They were native to both Eurasia and North America - fossils having been found in England, Germany, the Netherlands, Romania[1] and northern Greece. Mammut americanum is generally reported as having disappeared from North America about 10,000 years ago,[2] at the same time as most other Pleistocene megafauna. However more recent radiocarbon dates have been found, such as 5200 BC in Seneca, Michigan,[3] 5140 BC in Utah,[4] 4150 BC in Washtenaw, Michigan,[5] 4080 BC in Lapeer, Michigan.[6] It is known from fossils found ranging from present-day Alaska and New England in the north, to Florida, southern California, Mexico, and as far south as Honduras.[7]

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.[8] Their remains have been found as far as 300 kilometers offshore of the northeastern United States, in areas that were dry land during the low sea level stand of the last ice age.[9] Mastodon fossils have been found on the Olympic Peninsula of Washington, USA (Manis Mastodon Site),[10] in Kentucky (particularly noteworthy are early finds in what is now Big Bone Lick State Park);the floodplain of the East Branch of the DuPage River, near Glen Ellyn, Illinois;[11] the Kimmswick Bone Bed in Missouri; in Stewiacke, Nova Scotia, Canada; at a number of sites in New York State;[12] in Richland County, Wisconsin (Boaz mastodon); La Grange, Texas; Southern Louisiana; north of Fort Wayne, Indiana; Savannah, Georgia; and Johnstown, Ohio[13] USA.

[edit] Description

Life restoration of Mammut americanum.

While mastodons were furry like woolly mammoths[14] and similar in height at roughly three meters at the shoulder, the resemblance was superficial. They differed from mammoths primarily in the blunt, conical, nipple-like projections on the crowns of their molars,[15] which were more suited to chewing leaves than the high-crowned teeth mammoths used for grazing; the name mastodon (or mastodont) means "nipple teeth" and is also an obsolete name for their genus.[16] Their skulls were larger and flatter than those of mammoths, while their skeleton was stockier and more robust.[17] A few skeletons have been found with the fur still attached; examination of the hair suggests that mastodons also lacked the undercoat characteristic of mammoths.[17]

The tusks of the mastodon sometimes exceeded five meters in length and were nearly horizontal, in contrast with the more curved mammoth tusks.[17] Young males had vestigial lower tusks that were lost in adulthood.[17] 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 and modern elephants, mastodons may have had laterality.[17] 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.[18]

[edit] Extinction

Warren Mastodon skeleton

Recent studies indicate that tuberculosis may have been partly responsible for the extinction of the mastodon 10,000 years ago.[19]

Another influencing factor to their eventual extinction in America during the late Pleistocene may have been the presence of Paleo-Indians, who entered the American continent in relatively large numbers 13,000 years ago.[20] Their hunting caused a gradual attrition to the mastodon and mammoth populations, significant enough that over time the mastodons were hunted to extinction.[21]

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 x 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.[22]

[edit] Current excavations

Exhuming the First American Mastodon by Peale

Excavations conducted from 1993 through early 2000 at the Diamond Valley Lake reservoir outside of Hemet in Riverside County, California yielded numerous remains of mastodon, as well as numerous other Pleistocene animals. The abundance of these remains, all recovered by paleontologists from the San Bernardino County Museum, led to the site being nicknamed the "Valley of the Mastodons".

Current excavations are going on annually at the Hiscock Site in Byron, New York, for mastodon and related paleo-Indian artifacts. The site was discovered in 1959 by the Hiscock family while digging a pond with a backhoe; they found a large tusk and stopped digging. The Buffalo Museum of Science has organized the dig since 1983. It has been called[who?] one of the richest sites available for mastodon-related artifacts. The site sits on swampland that was covered by Lake Tonawanda, which was a glacier runoff lake formed over 10,000 years ago. It has been confirmed that mastodons would flock there to eat the sodium-rich clay during one of the last great droughts of the Paleolithic.

There were also excavations at Montgomery, New York in the late 1990s.

In August 2008, miners in Romania unearthed the skeleton of a 2.5 million-year-old mastodon, believed to be one of the best preserved in Europe[23]. Ninety percent of the skeleton's bones were intact, with damage to the skull and tusks[23]. In 2009 a family in Portland, Michigan unearthed mastodon bones while excavating a new pond on their property. It is one of approximately 250 mastodons found in Michigan over the past century.[24]

[edit] See also

[edit] References

  1. ^ 2.5 million-year-old mastodon unearthed in Romania
  2. ^ "Greek mastodon find 'spectacular'". BBC News. 24 July 2007. http://news.bbc.co.uk/2/hi/europe/6913366.stm. Retrieved on 2007-07-24. 
  3. ^ Richard E. Morlan, Bruggeman Mastodon, Canadian Archaeological Radiocarbon Database, www.canadianarchaeology.ca/localc14/c14search.htm, (Hull Quebec: Canadian Museum of Civilization), retrieved online October 2008).
  4. ^ Wade E. Miller, “Mammut Americanum: Utah’s First Record of the American Mastodon”, Journal of Paleontology, Volume 61, Number 1, (The Paleontological Society, 1987), 168-183.
  5. ^ Margaret Ann Skeels, “The Mastodons and Mammoths of Michigan”, Michigan Academician, Volume XXXIV, Number 3, (Ann Arbor: Michigan Academy of Science, 2002), 254.
  6. ^ H. R. Crane and James B. Griffin, Russell Farm, “University of Michigan Radiocarbon Dates IV”, Radiocarbon, Volume 1, Number 1, (New Haven: Yale, 1959), 178.
  7. ^ Polaco, O. J.; Arroyo-Cabrales, J.; Corona-M., E.; López-Oliva, J. G. (2001), "The American Mastodon Mammut americanum in Mexico", in Cavarretta, G.; Gioia, P.; Mussi, M. et al., The World of Elephants - Proceedings of the 1st International Congress, Rome October 16-20 2001, Rome: Consiglio Nazionale delle Ricerche, pp. 237–242, ISBN 88-8080-025-6 
  8. ^ Kurtén, Björn and Elaine Anderson. Pleistocene Mammals of North America. New York: Columbia University Press, 1980, p. 344.
  9. ^ Kurtén and Anderson, p. 344.
  10. ^ Kirk, Ruth and Richard D. Daugherty. Archaeology in Washington. Seattle: University of Washington Press, 2007.
  11. ^ http://www.wheaton.edu/Perry/start/start.html
  12. ^ Allmon, Warren D. and Peter L. Nester, editors. Mastodon Paleobiology, Taphonomy, and Paleoenvironment in the Late Pleistocene of New York State: Studies on the Hyde Park, Chemung, and North Java Sites. Ithaca, N.Y.: Paleontological Research Institution, 2008.
  13. ^ http://www.villageofjohnstown.org/history.html
  14. ^ Palmer, D., ed (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. pp. 124. ISBN 1-84028-152-9. 
  15. ^ Mastodons
  16. ^ Agusti, Jordi and Mauricio Anton (2002). Mammoths, Sabretooths, and Hominids. New York: Columbia University Press. pp. 106. ISBN 0-231-11640-3. 
  17. ^ a b c d e Kurtén and Anderson, p. 345
  18. ^ Fisher, D. (Oct. 18-21, 2006). "Tusk cementum defects record musth battles in American mastodons". Sixty-Sixth Annual Meeting of the Society of Vertebrate Paleontology. 
  19. ^ Mastodons Driven to Extinction by Tuberculosis, Fossils Suggest
  20. ^ Beck, Roger B.; Linda Black, Larry S. Krieger, Phillip C. Naylor, Dahia Ibo Shabaka, (1999). World History: Patterns of Interaction. Evanston, IL: McDougal Littell. ISBN 0-395-87274-X. 
  21. ^ Ward, Peter (1997). "The Call of Distant Mammoths". 
  22. ^ Flesher, John (2007-09-04). "Possible mastodon carving found on rock". Associated Press. http://news.yahoo.com/s/ap/20070904/ap_on_sc/mastodon_carving. Retrieved on 2007-09-05. 
  23. ^ a b 2.5 million-year-old mastodon unearthed in Romania, USA Today, 2008-08-08, Retrieved on 11 August 2008
  24. ^ "Michigan Family Finds Prehistoric Bones - Mastodon Bones To Be Given To University Of Michigan". The Associated Press. July 2, 2009. http://www.clickondetroit.com/news/19932305/detail.html. Retrieved on 3 July 2009. 

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