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Metatherian
Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as well as many extinct non-marsupial relatives. It is one of two groups placed in the clade Theria alongside Eutheria, which contains the placentals. Remains of metatherians have been found on all of Earth’s continents. Description Distinctive characteristics ( synapomorphies) of Metatheria include a prehensile tail, the development of a capitular tail on the humerus, the loss of tooth replacement on the second and fifth premolars, lower canines that outwardly diverge from each other, an angular process on the dentary bone—which additionally bears a posterior shelf in its masseteric fossa in Metatheria—that is equal to or greater than the length of the ramus, and the lower fifth premolar with a "very trenchant" cristid obliqua/ectol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sparassodonta
Sparassodonta (from Ancient Greek, Greek ['], to tear, rend; and , gen. [', '], tooth) is an extinct order (biology), order of carnivore, carnivorous metatherian mammals native to South America, related to modern marsupials. They were once considered to be true marsupials, but are now thought to be a separate side branch that split before the last common ancestor of all modern marsupials. A number of these mammalian predators closely resemble placental predators that evolved separately on other continents, and are cited frequently as examples of convergent evolution. They were first described by Florentino Ameghino, from fossils found in the Santa Cruz beds of Patagonia. Sparassodonts were present throughout South America's long period of "splendid isolation" during the Cenozoic; during this time, they shared the niches for large warm-blooded predators with the flightless Phorusrhacidae, terror birds. Previously, it was thought that these mammals died out in the face of competi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupial
Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a relatively undeveloped state and then nurtured within a pouch on their mother's abdomen. Extant marsupials encompass many species, including Kangaroo, kangaroos, Koala, koalas, Opossum, opossums, Phalangeriformes, possums, Tasmanian devil, Tasmanian devils, Wombat, wombats, Wallaby, wallabies, and Bandicoot, bandicoots. Marsupials constitute a clade stemming from the last common ancestor of extant Metatheria, which encompasses all mammals more closely related to marsupials than to Placentalia, placentals. The evolutionary split between placentals and marsupials occurred 125-160 million years ago, in the Middle Jurassic-Early Cretaceous period. Presently, close to 70% of the 334 extant marsupial species are concentrated on the Australian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupialia
Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a relatively undeveloped state and then nurtured within a pouch on their mother's abdomen. Extant marsupials encompass many species, including kangaroos, koalas, opossums, possums, Tasmanian devils, wombats, wallabies, and bandicoots. Marsupials constitute a clade stemming from the last common ancestor of extant Metatheria, which encompasses all mammals more closely related to marsupials than to placentals. The evolutionary split between placentals and marsupials occurred 125-160 million years ago, in the Middle Jurassic-Early Cretaceous period. Presently, close to 70% of the 334 extant marsupial species are concentrated on the Australian continent, including mainland Australia, Tasmania, New Guinea, and nearby islands. The remain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stagodontidae
Stagodontidae is an extinct family of carnivorous metatherian mammals that inhabited North America and Europe during the late Cretaceous, and possibly to the Eocene in South America. Description Currently, the family includes four genera, '' Eodelphis'', '' Didelphodon'', '' Fumodelphodon'' and '' Hoodootherium'', which together include some seven different species. In addition, the Cenomanian species '' Pariadens kirklandi'' might be a member of the family. Carneiro and Oliveira (2017) considered the species '' Eobrasilia coutoi'' from the early Eocene ( Itaboraian) of Brazil to be a stagodontid; if confirmed it would make it the only known Cenozoic and the only known South American member of the family. Stagodontids were some of the largest known Cretaceous mammals, ranging from in mass. One of the most unusual features of stagodontids are their robust, bulbous premolars, which are thought to have been used to crush freshwater mollusks, a diet that apparently evolved indepe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peradectidae
Peradectidae is a family of small metatherian mammals, spanning from the Paleocene (or possibly Latest Cretaceous) to the Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea .... Fossils are known from the Northern Hemisphere, including Europe, Asia and North America. The monophyly of the group has been questioned, with some authors suggesting that '' Peradectes'' should be the only genus placed in the family. The morphology of peradectids has been considered to be similar to opossums, with at least some exhibiting morphology suggesting a tree dwelling arboreal/scansorial lifestyle. Their diet is suggested to have included insects and fruit. Phylogenetic analysis suggest that they are less closely related to modern marsupials than herpetotheriids are. Cladogram after: Refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deltatheroida
Deltatheroida is an extinct group of basal metatherians that were distantly related to modern marsupials. The majority of known members of the group lived in the Cretaceous; one species, '' Gurbanodelta kara'', is known from the late Paleocene ( Gashatan) of China. Their fossils are restricted to Central Asia and North America. This order can be defined as all metatherians closer to '' Deltatheridium'' than to Marsupialia. When they were first identified in the 1920s, they were believed to be placentals and possible ancestors of the " creodonts" (a polyphyletic group of extinct carnivorous mammals from the Paleogene and Miocene), but this was later disproven. Nonetheless, deltatheroideans do converge on hyaenodontids, oxyaenids, carnivorans, dasyuromorphs, thylacoleonids and sparassodonts in many details of their dental anatomy, suggesting a carnivorous lifestyle.CHRISTIAN DE MUIZON and BRIGITTE LANGE-BADRÉ, Carnivorous dental adaptations in tribosphenic mammals and phylo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpetotheriidae
Herpetotheriidae is an extinct family of metatherians, closely related to marsupials. Species of this family are generally reconstructed as terrestrial, and are considered morphologically similar to modern opossums. They are suggested to have been insectivores. Fossils of herpetotheriids come from North America, Asia, Europe, Africa, and perhaps South America. The oldest representative is '' Maastrichtidelphys'' from the latest Cretaceous (Maastrichtian) of the Netherlands and the youngest member is '' Amphiperatherium'' from the Middle Miocene of Europe. The group has been suggested to be paraphyletic, with an analysis of petrosal anatomy finding that North American '' Herpetotherium'' was more closely related to marsupials than the European '' Peratherium'' and ''Amphiperatherium.'' The family includes the following genera: *'' Amphiperatherium'' (Early Eocene to Middle Miocene, Europe; synonyms: ''Oxygomphius'', ''Microtarsioides'', ''Ceciliolemur'') *'' Asiadidelphis'' (Lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holoclemensia
''Holoclemensia'' is an extinct genus of mammal of uncertain phylogenetic placement. It lived during the Early Cretaceous and its fossil remains were discovered in Texas. Description This genus is only known from a few isolated teeth. The upper molars had a paracone larger than the metacone, and a stylar platform with stylar cusps. The lower molars had a high protoconid, a small paraconid, and the hypoconulid and entoconid were close. Classification First described in 1968 by Slaughter, ''Holoclemensia texana'' is only known from a few teeth found in the Trinity Formation, in Texas. Slaughter initially described the remains under the name ''Clemensia'', but this name was already in use for a genus of moths and the genus was renamed ''Holoclemensia''. It was initially considered to be a basal marsupial, then was approached of the so-called group " Tribotheria", was later reconsidered as a marsupial, and was finally placed as a basal member of Metatheria Metatheria is a mam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatoliadelphyidae
Anatoliadelphyidae is an extinct family of metatherian mammals, endemic to the Pontide terrane (forming part of what is now modern Anatolia), during the Middle Eocene (Lutetian The Lutetian is, in the geologic timescale, a stage (stratigraphy), stage or age (geology), age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it ...), around 43 million years ago, when the terrane formed an island landmass with an insular endemic fauna, which also included herpetotheriid and polydolopimorphian metatherians, as well as archaic pleuraspidotheriid ungulates and enigmatic insectivores. The cat-sized '' Anatoliadelphys'' is the best known member, and is thought to have been a carnivore or omnivore. References {{Taxonbar, from=Q59534705 Metatheria Prehistoric mammal families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asiadelphia
''Asiatherium'' is an extinct genus of mammal, probably belonging to Metatheria. It lived during the Late Cretaceous, and its fossilized remains were discovered in Mongolia. Description Skull of ''Asiatherium'' is in length. This animal was roughly the size of a mouse, and is known from a fairly complete articulated skeleton, preserving a complete skull. Its teeth resembled roughly those of marsupials; it possessed three premolars and four molars, and the mandible was slightly curved. Compared to '' Deltatheridium'', ''Asiatherium'' was even more marsupial-like, due to its molars having paraconids lower than the metaconids, and the paired entoconid-hypoconulid cusps on the lower molars. The stylar platform of the upper molars was however narrower and the stylar cusps weaker than in primitive marsupials. The upper molars differed from those of marsupials in their expanded praecingula and postcingula.*F. S. Szalay and B. A. Trofimov. 1996. The Mongolian Late Cretaceous Asiatherium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinodelphys
''Sinodelphys'' is an extinct mammal from the Early Cretaceous, estimated to be 125 million years old. It was discovered and described in 2003 in rocks of the Yixian Formation in Liaoning Province, China, by a team of scientists including Zhe-Xi Luo and John Wible. While initially suggested to be the oldest known metatherian, later studies interpreted it as a eutherian. Description Only one fossil specimen is known, a slab and counterslab given catalog number CAGS00-IG03. It is in the collection of the Chinese Academy of Geological Sciences. ''Sinodelphys szalayi'' grew only 15 cm (5.9 in) long and possibly weighed about 30 g (1.05 oz). Its fossilized skeleton is surrounded by impressions of fur and soft tissue, thanks to the exceptional sediment that preserves such details. Luo et al. (2003) inferred from the foot structure of ''Sinodelphys'' that it was a scansorial tree-dweller, like the contemporary '' Eomaia'' and modern opossums such as '' Didelphis' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutheria
Eutheria (from Greek , 'good, right' and , 'beast'; ), also called Pan-Placentalia, is the clade consisting of Placentalia, placental mammals and all therian mammals that are more closely related to placentals than to marsupials. Eutherians are distinguished from non-eutherians by various phenotypic traits of the feet, ankles, jaws and teeth. All extant eutherians lack epipubic bones, which are present in all other living mammals (marsupials and monotremes). This allows for expansion of the abdomen during pregnancy, though epipubic bones are present in many primitive eutherians. Eutheria was named in 1872 by Theodore Gill; in 1880, Thomas Henry Huxley defined it to encompass a more broadly defined group than Placentalia. The earliest unambiguous eutherians are known from the Early Cretaceous Yixian Formation of China, dating around 120 million years ago. Two tribosphenic mammals, ''Durlstodon'' and ''Durlstotherium'' from the Berriasian age (~145–140 million years ago) of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
