Marsupials are mammals in which the female typically has a pouch in which it rears its young through early infancy.
They differ from placental mammals (Placentalia) in their reproductive traits.
The early birth of marsupials removes the developing young much sooner than in placental mammals, and marsupials have not needed to develop a complex placenta to protect the young from its mother's immune system.
Early birth places the tiny newborn marsupial at greater risk, but significantly reduces the risks associated with pregnancy, as there is no need to carry a large fetus to full-term in bad seasons.
There are about 334 species of marsupials, over 200 of them native to Australia and nearby islands to the north.
Mammal The mammals are the class of vertebrate animals characterized by the production of milk in females for the nourishment of young, from mammary glands ... >
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Placenta The placenta is an ephemeral (temporary) organ present only in female placental vertebrates during gestation (pregnancy). All mammals other than ... >
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Koala The Koala (Phascolarctos cinereus) is a thickset arboreal marsupial herbivore native to Australia, and the only extant representative of the family, ... >
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Sugar Glider The Sugar Glider (Petaurus breviceps), sometimes called the Flying Sugar, is a small gliding possum native to eastern and northern mainland ... >
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Rodent Rodentia is an order of mammals also known as rodents, characterised by two continuously-growing incisors in the upper and lower jaws which must be ... >
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Tasmanian Devil The Tasmanian Devil, also referred to simply as 'the devil', is a carnivorous marsupial now found only in the Australian island state of ... >
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Semen Semen or sperm is a fluid that contains spermatozoa. It is secreted by the gonads (sexual glands) of male or hermaphroditic animals, including ... >
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Primate A primate is any member of the biological order Primates, the group that contains all the species commonly related to the lemurs, monkeys, and apes, ... >
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Sex linkage Sex linkage is the phenotypic expression of an allele that is dependent on the gender of the individual and is directly tied to the sex chromosomes. ... >
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Parallel evolution Parallel evolution is the independent evolution of similar traits, starting from a similar ancestral condition. Frequently this is the situation in ... >
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