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Metatheria
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. There are three extant subclasses of mammals, one being metatherians: #monotremes: egg laying mammals like the platypus and the echidna, #metatheria: marsupials, which includes three American orders ( Didelphimorphia, Paucituberculata and Microbiotheria) and four Australasian orders (Notoryctemorphia, Dasyuromorphia, Peramelemorphia and Diprotodontia), and the # eutherians: placental mammals, consisting of four superorders divided into 21 orders. Metatherians belong to a subgroup of the northern tribosphenic mammal clade or Boreosphenida. They differ from all other mammals in certain morphologies like their dental formula, which includes about five upper and four lower incisors, a canine, three pre ... [...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 competit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupialia
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch (marsupial), pouch. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, Wallaby, wallabies, bandicoots, and the extinct thylacine. Marsupials represent the clade originating from the last common ancestor of extant metatherians, the group containing all mammals more closely related to marsupials than to Placentalia, placentals. They give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. Close to 70% of the 334 extant taxon, extant species occur on the Australia (continent), Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupial
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, wallabies, bandicoots, and the extinct thylacine. Marsupials represent the clade originating from the last common ancestor of extant metatherians, the group containing all mammals more closely related to marsupials than to placentals. They give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. Close to 70% of the 334 extant species occur on the Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in Central America, and one species, the Virginia opossum, in North America, n ... [...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 independent ... [...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. These mammals possessed primitive tritubercular (three-cusped) lower molars that were not tribosphenic. This is awkward because tribosphenic molars are commonly found in most therian mammals (there exist some exceptions such as anteaters and some whales, which have no teeth at all). 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 ... [...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. 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'' (Late Eocene to Early Oligocene, Kazakhstan and Pakist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinodelphys
''Sinodelphys'' is an extinct eutherian 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. Fossil record 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 its non-marsupial contemporary ''Eomaia'' and modern opossums such as ''Didelphis''. ''Sinodelphys'' probably hunted worms and insects. Most Mesozoic metatherians have been foun ... [...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 or 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 is sometimes referred to as the Midd ...), 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. References {{Taxonbar, from=Q59534705 Metatheria Prehistoric mammal families ... [...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.*Luo, Z.-X., Q. Ji, J. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asiadelphia
Asiatheriidae ("Asian opossums") is an family of Cretaceous metatherians in the order Asiadelphia. Different from the Ameridelphia, they lacked a prominent distolateral process on the scaphoid, and possessed a more slender fibula. The masseteric fossa is deeper in this group than the true marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a po ...s. Further reading Zofia Kielan-Jaworowska, Richard L. Cifelli, and Zhe-Xi Luo, ''Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure'' (New York: Columbia University Press, 2004), 15, 451–452. Prehistoric metatherians Coniacian genus first appearances Campanian genus extinctions Fossil taxa described in 1994 Prehistoric mammal families {{cretaceous-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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