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Ameridelphia
Ameridelphia is traditionally a superorder that includes all marsupials living in the Americas except for the monito del monte (''Dromiciops''). It is now regarded as a paraphyletic group. Orders The orders within this group are listed below: * Order Didelphimorphia (108 species) ** Family Didelphidae: opossums * Order Paucituberculata (7 species) **Family Caenolestidae: shrew opossums Evolution and phylogenetics Modern marsupials are now understood to be an originally South American lineage that later reached Australia and diversified there in a massive adaptive radiation. Molecular data, including analysis of retrotransposon insertion sites in the nuclear DNA of a variety of marsupials, and the fossil evidence indicate that Ameridelphia might best be understood as an evolutionary grade. Since Didelphimorphia appears to be the basal marsupial group, it and Paucituberculata do not seem to be closest relatives. Meanwhile, the unranked clade Eomarsupialia has been pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupials Of North America
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 remainin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paucituberculata
Paucituberculata is an order of South American marsupials. Although currently represented only by the seven living species of shrew opossums, this order was formerly much more diverse, with more than 60 extinct species named from the fossil record, particularly from the late Oligocene to early Miocene epochs. The earliest paucituberculatans date to the late Paleocene ( Itaboraian South American land mammal age). The group went through a pronounced decline in the middle Miocene epoch, which resulted in the extinction of all families of this order except for the living shrew opossums (Caenolestidae). Extinct families of Paucituberculatans include Pichipilidae, Palaeothentidae, and Abderitidae. Classification It is one of two clades of Ameridelphia, a paraphyletic group; genetic studies have shown these animals to be a sister group to Australidelphia (i.e., Didelphimorphia branched off first). However, other studies have shown that shrew opossums branched off first, and thus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eomarsupialia
Australidelphia is a superorder of marsupials encompassing about three-quarters of all living marsupial species, including all those native to Australasia and one South American species, the monito del monte. Unlike other American marsupials, which belong to the Ameridelphia, Australidelphia’s lineage emerged in South America, with genetic evidence (retrotransposon insertion sites) showing the monito del monte as its most ancient branch. Within this superorder, the Australian members form a distinct group (clade) named Eomarsupialia, though their internal relationships (branching order) is yet to be determined. Studies suggest Australidelphia originated in South America alongside other major marsupial groups, likely dispersing to Australia via Antarctica in a single event after the monito’s lineage ( Microbiotheria) diverged, leaving other South American orders (Didelphimorphia and Paucituberculata) as more basal. Phylogeny The following cladogram is a phylogeny of Austra ... [...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] |
Australidelphia
Australidelphia is a superorder of marsupials encompassing about three-quarters of all living marsupial species, including all those native to Australasia and one South American species, the monito del monte. Unlike other American marsupials, which belong to the Ameridelphia, Australidelphia’s lineage emerged in South America, with genetic evidence (retrotransposon insertion sites) showing the monito del monte as its most ancient branch. Within this superorder, the Australian members form a distinct group (clade) named Eomarsupialia, though their internal relationships (branching order) is yet to be determined. Studies suggest Australidelphia originated in South America alongside other major marsupial groups, likely dispersing to Australia via Antarctica in a single event after the monito’s lineage ( Microbiotheria) diverged, leaving other South American orders (Didelphimorphia and Paucituberculata) as more basal. Phylogeny The following cladogram is a phylogeny of Aust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupials Of South America
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 remainin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caenolestidae
The family Caenolestidae contains the seven surviving species of shrew opossum: small, shrew-like marsupials that are confined to the Andes mountains of South America. The order is thought to have diverged from the ancestral marsupial line very early. They were once included in the superorder but it is now known that Ameridelphia is paraphyletic, having given rise to Australidelphia, and thus could be considered an evolutionary grade. Genetic studies indicate that they are the second most basal order of marsupials, after the didelphimorphs. As recently as 20 million years ago, at least seven genera were in South America. Today, just three genera remain. They live in inaccessible forest and grassland regions of the High Andes. Shrews were entirely absent from South America until the Great American Interchange three million years ago, and are currently present only in the northwestern part of the continent. Traditionally, it was thought that shrew opossums lost ground to these and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupials
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 remaini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbiotheria
Microbiotheria is an australidelphian marsupial order that encompasses two families, Microbiotheriidae and Woodburnodontidae, and is represented by only one extant species, the monito del monte, and a number of extinct species known from fossils in South America, Western Antarctica, and northeastern Australia. Although once thought to be members of the order Didelphimorphia (the order that contains the Virginia opossum), an accumulation of both anatomical and genetic evidence in recent years has led to the conclusion that microbiotheres are not didelphids at all, but are instead most closely related to the Australasian marsupials; together, the microbiotheres and the Australian orders form the clade Australidelphia which are now thought to have first evolved in the South American region of Gondwana. Biogeography The oldest microbiothere currently recognised is '' Khasia cordillerensis'', based on fossil teeth from Early Palaeocene deposits at Tiupampa, Bolivia. Numerous ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virginia Opossum
The Virginia opossum (''Didelphis virginiana''), also known as the North American opossum, is a member of the opossum family found from southern Canada to northern Costa Rica, making it the northernmost marsupial in the world and the only marsupial native to North America. Commonly referred to simply as the possum, it is a solitary nocturnal animal about the size of a domestic cat, and a successful Opportunism#Biological, opportunist. Opossums are familiar to many North Americans as they frequently inhabit settled areas near food sources like trash cans, pet food, compost piles, gardens or housemice. Their slow, nocturnal nature and their attraction to roadside carrion make opossums more likely to become roadkill. Name The Virginia opossum is the original animal named "opossum", a word which comes from Algonquian languages, Algonquian , meaning "white animal". Colloquially, the Virginia opossum is frequently just called a "possum". The term is applied more generally to any of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Living Fossil
A living fossil is a Deprecation, deprecated term for an extant taxon that phenotypically resembles related species known only from the fossil record. To be considered a living fossil, the fossil species must be old relative to the time of origin of the extant clade. Living fossils commonly are of species-poor lineages, but they need not be. While the body plan of a living fossil remains superficially similar, it is never the same species as the remote relatives it resembles, because genetic drift would inevitably change its chromosomal structure. Living fossils exhibit punctuated equilibrium, stasis (also called "bradytely") over geologically long time scales. Popular literature may wrongly claim that a "living fossil" has undergone no significant evolution since fossil times, with practically no molecular evolution or Morphology (biology), morphological changes. Scientific investigations have repeatedly discredited such claims. The minimal superficial changes to living foss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
