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Proboscidea

From Wikipedia, the free encyclopedia

 

Proboscidea

Fossil range: Late Paleocene - Recent

African Elephant

African Elephant

Scientific classification

Kingdom:

Animalia

Phylum:

Chordata

Class:

Mammalia

Order:

Proboscidea
Illiger, 1811

Groups

Jozaria (extinct)
Anthracobunidae (extinct)
Moeritheriidae (extinct)
Euproboscidea

Numidotheriidae (extinct)

Barytheriidae (extinct)

Phiomiidae (extinct)

Deinotheriidae (extinct)

Elephantiformes

Palaeomastodontidae (extinct)

Hemimastodontidae (extinct)

Euelephantoidea

Choerolophodontidae (extinct)

Amebelodontidae (extinct)

Gnathabelodontidae (extinct)

Gomphotheriidae (extinct)

Elephantidae

Mammutidae (extinct)

Stegodontidae (extinct)

 

 

Proboscidea is an order containing only one family of living animals, Elephantidae, the elephants, with three living species (African Bush Elephant, African Forest Elephant, and Asian Elephant)[1].

During the period of the last ice age there were more, now extinct species, including a number of species of the elephant-like mammoths and mastodons. Further back in time, in the late Tertiary, there were many more different types, including the bizarre "shovel tuskers" like Platybelodon and Amebelodon. The earliest known proboscidean is Phosphatherium dating from paleocene deposits of Morocco. From the Eocene, several very primitive proboscideans are known, including the African Numidotherium, Barytherium, Moeritherium and the anthracobunidae from the Indo-Pakistanese subcontinent.

Origins

Paleontologists know of about 170 fossil species which they classify as belonging to the Proboscidea (Gr. proboskis, elephant's trunk, from pro, before, + boskein, to feed) group. The oldest dates from the early Tertiary period, over 50 million years ago. A discovery in December, 2003 has forced a new estimate of the age of elephant-like species to around 26 million years. Most of these early elephants had four short tusks; two on the upper jaw and two on the lower. Primelephas, the ancestor of mammoths and modern elephants, appeared in the late Miocene epoch, about 7 million years ago. The evolution of the elephant-like animals mainly concerned the proportions of the cranium and jaw and the shape of the tusks and molar teeth.

References

1.     ^ Shoshani, Jeheskel (November 16, 2005). Wilson, D. E., and Reeder, D. M. (eds): Mammal Species of the World, 3rd edition, Johns Hopkins University Press, 90-91. ISBN 0-801-88221-4. 

Mastodon

From Wikipedia, the free encyclopedia

 

Mastodon

Mastodon skeleton

Conservation status

Pre

Scientific classification

Kingdom:

Animalia

Phylum:

Chordata

Class:

Mammalia

Order:

Proboscidea

Family:

Mammutidae
Hay, 1922

Genus:

Mammut

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.

Habitat

The American mastodon (Mammut americanum) lived in North America. Mastodons first appeared almost four million years ago and became extinct 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 Eastern United States, as well as in warmer lowland environments.[1] Their remains have been found as far as 300 kilometers offshore in Northeastern United States, in areas that were dry land during the low sea level stand of the last ice age.[2] There have been, however, findings of mastodon fossils in South America and also on the Olympic Peninsula of Washington state.[3]

The tusks of the mastodon sometimes exceeded five meters in length, and were nearly horizontal, another contrast with more strongly curved mammoth tusks.[4] Young males had vestigial lower tusks that were lost in adulthood.[4] 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.[4] 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.[5]

Extinction

The Mastadon is currently extinct, unless you count the Mastodon Dinozord.

References

1.     ^ Björn Kurtén and Elaine Anderson, Pleistocene Mammals of North America, (New York: Columbia UP, 1980), p. 344.

2.     ^ Kurtén and Anderson, p. 344.

3.     ^ Kirk and Daugherty, Archaeology in Washington, forthcoming from University of Washington Press, April 2007.

4.     ^ a b c

5.     ^ 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.

The mastodon in popular culture

 

 

Wikipedia

http://en.wikipedia.org/w/index.php?title=Proboscidea&action=history

http://en.wikipedia.org/w/index.php?title=Mastodon&action=history

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