Proboscidea

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Proboscidea

[‚prō·bə′sid·ē·ə]
(vertebrate zoology)
An order of herbivorous placental mammals characterized by having a proboscis, incisors enlarged to become tusks, and pillarlike legs with five toes bound together on a broad pad.

Proboscidea

 

an order of mammals. The earliest representatives of the order Proboscidea were relatively small animals; later ones were larger, reaching a height of 4.5 m. The legs are long and columnar. The forelegs are five-toed, and the hind legs are four- or five-toed. The neck is short, and the head almost immovable. The highly developed upper lip and the nose concresce to form the movable proboscis, or trunk. In the earliest representatives the proboscis was very small or apparently absent. The dental system is characterized by the absence of canines (except in Moeritherium) and first incisors. The highly developed second incisors (tusks) are marked by constant growth. The molars have broad chewing surfaces that are nodular or have transverse ridges, sometimes with plates. The teeth are formed from dentine and enamel; only in elephants and some mastodonts is cement deposited between the ridges or plates.

The oldest Proboscidea are known from Africa, where their remains have been found in Middle Eocene deposits. Proboscidea were subsequently widely distributed in Africa, Eurasia, and America. At present they are found only in Africa and South Asia. Most species inhabited tropical rain forests; some were apparently semi-aquatic. Only elephants were adapted to life in diverse environments—forests, forest steppes, steppes, and tundra. There are three suborders: Moeritherioidea, Elephantoidea, and Deinotherioidea. The first and third suborders are extinct.

Elephantoidea include three families: Gomphotheriidae, Mastodontidae, and Elephantidae. Extant species belong only to the last family.

REFERENCES

Osnovy paleontologii: Mlekopitaiushchie. Moscow, 1962.
Osborn, H. F. Proboscidea: A Monograph of the Discovery, Evolution, Migration and Extinction of the Mastodonts and Elephants of the World, vols. 1–2. New York, 1936–42.

V. E. GARUTT

References in periodicals archive ?
These publications interrelate critically with other proboscidean papers published elsewhere.
conversidens,andan indeterminate large proboscidean.
These early proboscideans (animals with a trunk) were subtropical forms, not the cold-loving animals that some of their descendants became.
As in the case of the peccaries, various genera of proboscideans also demonstrate different ecological affinities and preferences (Lundelius, 1967:297); both the dentition and habitat preferences of mastodons (Mammut sp.
The skull and mandible of proboscideans often lag behind other skeletal elements in a depositional environment, mainly because of flotation of the skull due to diploe (Voorhies, 1969; Agenbroad and Mead, 1994).
Since the last detailed publication on the Pleistocene vertebrates of Michigan (Wilson 1967), much new information has accumulated: new sites have been found; ranges have been extended; C-14 dates have been obtained; vertebrates have for the first time been identified from a Wisconsinan interstadial interval; and butchering of extinct proboscideans by humans has been demonstrated at several localities.
This is the first case of a supernumerary tooth formed by fusion documented in an extinct proboscidean.
1986,447, and in this report) needs to be examined in detail, for it may include additional individual proboscideans (pers.
The few records of Michigan Pleistocene vertebrates, other than the numerous reported occurrences of proboscideans, is are striking (Holman 1988).
Proboscideans from the Pleistocene of Michigan are the American mastodont (Mammut americanum) and mammoth (Mammuthus spp.
This is probably the topic most often discussed regarding the occurrence of proboscideans in Michigan.
1986, 447, and in this report) needs to be examined in detail, for it may include additional individual proboscideans (pers.