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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
All of the discussants at this yearly forum doubtlessly would agree that the most awesome and important members of the Pleistocene fauna are the mastodonts and mammoths, huge proboscideans (elephant-like beasts) that were the dominant members of the terrestrial community of the time.
Beginning 50 million years ago, and as recently as the late Pleistocene, 10,000 or so years ago, proboscideans roamed the globe.
The current study adds to the fossil record two recently investigated proboscideans from Nogal, New Mexico.
In the late 1960s and 1970s, several researchers discovered proboscidean limb bones from the Old Crow River area, Yukon, that were interpreted to have been modified by humans using percussion technology to produce notches and bone flakes (Harington et al., 1975; Irving, 1978; Bonnichsen, 1979; Morian, 1980; Morlan and Cinq-Mars, 1982; Irving et al., 1986; Cinq-Mars and Morian, 1999).
Unlike archival readings, which indicate only how elephants resist human placings, this ecological rendition enables an engagement with the ways through which elephants create their own spaces, where their proboscidean ways, ends, doings can be reflected.
The idea that Skeels put forth--that the deep muck and peat and floating mats of vegetation ("quaking bogs") in the late Pleistocene were natural traps that these heavy animals would have broken through--is still accepted as primary taphonomic event involved in the fossilization of these proboscideans. The fact most fossil proboscideans in Michigan have been excavated from former shallow basins of kettle bog sites attests to this hypothesis.
This following paper is significant in that it provides the oldest record of a Pleistocene proboscidean in Michigan.
This is the first case of a supernumerary tooth formed by fusion documented in an extinct proboscidean.