Eutheria 216676 224479431 2008-07-09T00:57:37Z Thijs!bot 1392310 robot Adding: [[fi:Istukkanisäkkäät (osaluokka)]] {{Disputed|date=March 2008}} {{Expand|date=January 2007}} {{Taxobox | name = Placental mammals / Eutheria | fossil_range = Early [[Cretaceous]] - Recent | image = house_mouse.jpg | image_width = 270px | image_caption = [[House Mouse]], ''Mus musculus'' | regnum = [[Animal]]ia | phylum = [[Chordate|Chordata]] | classis = [[Mammal]]ia | subclassis = [[Theria]] | infraclassis = '''Eutheria''' | infraclassis_authority = [[Thomas Henry Huxley]], [[1880]] | subdivision_ranks = Orders<ref>{{cite web|title=Eutheria phylogeny|work=Mikko's Phylogeny Archive|accessdate=2006-03-08|url=http://www.fmnh.helsinki.fi/users/haaramo/Metazoa/Deuterostoma/Chordata/Synapsida/Eutheria/Eutheria_1.htm#Edentata}}</ref> | subdivision = *''[[Bobolestes]]'' *''[[Eomaia]]'' *''[[Maelestes]]'' *''[[Montanalestes]]'' *''[[Murtoilestes]]'' *''[[Prokennalestes]]'' *'''Placentalia''' **Superorder '''[[Xenarthra]]:''' ***[[Cingulata]] (Armadillos) ***[[Pilosa]] (Sloths, True Anteaters) **Superorder '''[[Laurasiatheria]]:''' ***[[Pholidota]] (Scaly Anteaters) ***[[Soricomorpha]] (Moles, Shrews) ***[[Erinaceomorpha]] (Hedgehogs) ***[[Perissodactyla]] (Horses, Rhinoceroses and Tapirs) ***[[Cetartiodactyla]] (Bovids, Pigs, Cervids, Camels, Whales, Dolphins) ***[[Carnivora]] (Cats, Dogs, Bears, Seals) ***[[Chiroptera]] (Bats) ***†[[Meridiungulata]] ***†[[Condylarthra]] ***†[[Dinocerata]] ***†[[Mesonychia]] ***†[[Cimolesta]] ***†[[Creodonta]] **Superorder '''[[Afrotheria]]:''' ***[[Afrosoricida]] (Tenrecs) ***[[Hyracoidea]] (Hyraxes) ***[[Macroscelidea]] (Elephant Shrews) ***[[Proboscidea]] (Elephants) ***[[Sirenia]] (Manatees, Dugongs) ***[[Tubulidentata]] (Aardvark) ***†[[Embrithopoda]] ***†[[Desmostylia]] **Superorder '''[[Euarchontoglires]]:''' ***[[Dermoptera]] (Colugos) ***[[Lagomorpha]] (Rabbits, Hares) ***[[Primates]] (Apes, Monkeys) ***†[[Plesiadapiformes]] ***[[Rodent]]ia (Rodents) ***[[Scandentia]] (Treeshrews) }} '''Eutheria'''<ref name="Placentalia">Today [[Placentalia]] and Eutheria are sometimes considered to be the same group. But there are proposals of classification (McKenna & Bell, 1997) that differentiate between the two groups.</ref> is a [[taxon]] containing the [[placenta]]l [[mammal]]s, such as [[human]]s. The [[sister group]] of Eutheria is [[Metatheria]], which includes [[marsupial]]s and their extinct relatives. ==Origin of the word== The name Eutheria comes from the [[Greek (language)|Greek]] words ''eu-'' "well[-developed]" and ''ther'' "beast". When Eutheria was introduced by [[Thomas Henry Huxley]] in [[1880]], he meant it to be broader in definition than its precursor '''Placentalia'''. Some use Eutheria as a [[total group]] which includes the [[crown group]] Placentalia and extinct mammals which are closer to Placentalia than to [[Marsupialia]]. ==Characteristics of eutherians== Nevertheless, all living eutherians are placental mammals. This means that a eutherian [[fetus]] is nourished during gestation by a [[placenta]]. Eutherians are also [[viviparous]], meaning that the offspring are carried in the mother's [[uterus]] until fully developed. ==Differences from other mammals== Because of this, eutherians are different from other mammal groups such as [[monotremes]] and [[marsupials]] which are not placental. Monotremes, for instance, lay [[Egg (biology)|eggs]] which protect developing young until they are fully developed. Marsupials give birth to partially-developed young who then migrate to a special [[pouch (marsupial)|pouch]] in the mother's body in which the young continue their development. (Some exceptions do exist. [[Bandicoots]] for instance, which are marsupials, develop small placenta-like structures during gestation.) ==Earliest example== The earliest known eutherian species is the extinct ''[[Eomaia|Eomaia scansoria]]'' from the Lower [[Cretaceous]] of [[China]]. It is a member of Eutheria, but the hips of the animal were too narrowly built to have allowed the birth of well-developed young. Thus it is unlikely that a placenta greatly contributed to the development of ''E. scansoria's'' young before they were born. Members of Eutheria are found on all continents and in all oceans. ==See also== *[[List of placental mammals]] *[[Mammal]] for classification. *[[Theria]] ===Compare and contrast=== *[[Metatheria]] *[[Prototheria]] {{wikispecies|Eutheria}} ==Notes and references== Detailed [[cladogram]] of [[extant]] Placentalia from [http://www.pnas.org/content/vol100/issue3/images/large/pq0334222002.jpeg Proceedings of the National Academy of Sciences], February 4, 2003, vol. 100, no. 3, pp. 1056-1061. <references /> {{Mammals}} [[Category:Mammals]] [[bg:Плацентни]] [[ca:Euteri]] [[cs:Placentálové]] [[de:Höhere Säugetiere]] [[es:Placentalia]] [[eo:Placentuloj]] [[fr:Placentalia]] [[ko:진수하강]] [[hr:Viši sisavci]] [[id:Eutheria]] [[it:Eutheria]] [[lb:Héijer Mamendéieren]] [[lij:Placentalia]] [[hu:Méhlepényesek]] [[nl:Placentadieren]] [[ja:真獣下綱]] [[no:Placentale pattedyr]] [[oc:Eutheria]] [[pl:Łożyskowce]] [[pt:Placentários]] [[ro:Eutheria]] [[ru:Плацентарные]] [[sl:Višji sesalci]] [[fi:Istukkanisäkkäät (osaluokka)]] [[sv:Högre däggdjur]] [[th:ยูเธอเรีย]] [[zh-yue:真獸亞綱]] [[zh:真獸下綱]]