• WordNet 3.6
    • n Marsupialia coextensive with the subclass Metatheria
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Webster's Revised Unabridged Dictionary
    • prop. n. pl Marsupialia mär*sū`pĭ*ā"lĭ*ȧ (Zoöl) A subclass of Mammalia, including nearly all the mammals of Australia and the adjacent islands, together with the opossums of America. They differ from ordinary mammals in having the corpus callosum very small, in being implacental, and in having their young born while very immature. The female generally carries the young for some time after birth in an external pouch, or marsupium. Called also Marsupiata.
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Century Dictionary and Cyclopedia
    • marsupialia An order of the class Mammalia, coextensive with the subclass Didelphia, containing implacental mammals usually provided with a marsupium or pouch for the reception and nourishment of the young; the marsupials or pouched animals. There being no developed placenta, the period of gestation is very brief, and the young are born extremely small, imperfect, and quite helpless. In this state they are immediately transferred to the pouch on the belly of the mother, where are the teats, to which the little creatures adhere firmly for a while, completing their development by sucking milk. As they grow larger and stronger, they are able to let go and take hold of the teat again; and even after leaving the pouch they may for a while retreat to it, or be carried about elsewhere on the mother's body. (See cut under marmose.) The uterus is double, and the vagina also is more or less completely divided into two separate passages (whence the name Didelphia); the scrotum of the male is abdominal in position, and pendulous, in front of the penis. The corpus callosum is rudimentary, but the cerebral hemispheres are connected by a well-developed anterior commissure. The angle of the mandible is normally inflected. There is a wide range of adaptive modification in the structural details of the marsupials, the order in itself including representatives or analogues of nearly all the other orders of mammals, as the carnivorous, the insectivorous, the herbivorous, etc. At the present time the marsupials are eminently characteristic of the Australian region, only the Didelphyidæ or opossums being found in America; but in former epochs the distribution of the marsupials was general, and some of the oldest known mammalian fossils of Mesozoic age are supposed to belong to this order. It has been variously subdivided. Owen in 1839 divided it into five tribes, Sarcophaga, Entomophaga, Carpophaga, Poëphaga, and Rhizophaga. A main division, based on the dentition, is into Diprotodontia and Polyprotodontia. In 1872 Gill made the four suborders Rhizophaga, Syndactyli, Dasyuromorpha, and Didelphimorpha, with nine families, Phascolomyidæ, Macropodidæ, Tarsipedidæ, Phalangistidæ, Phascolarctidæ, Peramelidæ, Dasyuridæ, Myrmecobiidæ, and Didelphyidæ, for the living forms, and four fossil families, Diprotodontidæ, Thylacoleontidæ, Plagiaulacidæ, and Dromatheriidæ. Also called Marsupiata.
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Webster's Revised Unabridged Dictionary
NL., fr. L. marsupium, a pouch, bag, purse, Gr. marsy`pion, dim. of ma`rsypos ma`rsipos


In literature:

Marsupialia, compared with placentata.
"More Letters of Charles Darwin Volume II" by Charles Darwin
The field mouse and rabbits are rodentia, the deer ungulata, the kangaroos marsupialia.
"Concerning Animals and Other Matters" by E.H. Aitken, (AKA Edward Hamilton)
From the primary mammal arose the pouched animals (marsupialia).
"Was Man Created?" by Henry A. Mott
The Monotremata and Marsupialia have curious Y-shaped spleens.
"Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 8" by Various
Marsupialia (or Metatheria), 161.
"Stories of the Universe: Animal Life" by B. Lindsay
SEVENTEENTH STAGE: +Pouched Animals (Marsupialia)+.
"The History of Creation, Vol. II (of 2)" by Ernst Haeckel