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Pegasoferae
Pegasoferae ("winged beast") is a proposed clade of mammals based on genomic research in molecular systematics by Nishihara, Hasegawa and Okada (2006). To the surprise of the authors, their data led them to propose a clade that includes bats (order Chiroptera), carnivores such as cats and dogs (order Carnivora), horses and other odd-toed ungulates (order Perissodactyla) and pangolins (order Pholidota) as springing from a single evolutionary origin within the mammals. The name Pegasoferae was coined from the name of the mythological flying horse Pegasus to refer to bats and horses, and the term Ferae, encompassing carnivorans and pangolins. According to this, the odd-toed ungulates' closest living relatives are the carnivorans. Earlier theories of mammalian evolution would, for example, have aligned bats with the insectivores (order Eulipotyphla) and horses with the even-toed ungulates (order Artiodactyla The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zooamata
Zooamata ("animal friends") is a proposal for a clade of mammals uniting the Ferae (Carnivora, carnivores and pangolins) with the Perissodactyla (odd-toed ungulates). Zoomata was proposed as one of the competing arrangements for the interordinal relationships of placental mammals within Laurasiatheria. It received support in a phylogenetic study using retroposon insertion analysis, where it was found to be the sister taxon to Chiroptera within a novel clade named Pegasoferae. The Zooamata and Cetartiodactyla (even-toed ungulates and whales) together form Scrotifera. The name of this clade is constructed from Greek language, Greek and Latin to mean "animal friends", a reference to the inclusion of cats, dogs, and horses, all of which have been domesticated by humans. Subsequent molecular studies have generally failed to support the proposal. In particular, two recent phylogenomic studies analysing alternative theories for mammalian interordinal relationships concluded that Zooa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scrotifera
Scrotifera ("beasts with scrotum") is a clade of Placentalia, placental mammals that groups together grandorder Ferungulata, clade Bat, Apo-Chiroptera (aka Order (biology), order Bat, Chiroptera), other extinct members and their common ancestors. The clade Scrotifera is a sister group to the order Eulipotyphla (true insectivores) based on evidence from molecular phylogenetics, and together they make superorder Laurasiatheria. The last common ancestor of Scrotifera is supposed to have diversified ca. 73.1 to 85.5 million years ago. Etymology Peter Waddell, then of the Institute of Statistical Mathematics, explains the etymology of the clade's name as follows: The name comes from the word ''scrotum'', a pouch in which the Testicle, testes permanently reside in the adult male. All members of the group have a postpenile scrotum, often prominently displayed, except for some aquatic forms and pangolin (which has the testes just below the skin). It appears to be an ancestral character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferae
Ferae ( , , "wild beasts") is a mirorder of placental mammalsMalcolm C. McKenna, Susan K. Bell: ''Classification of Mammals: Above the Species Level'' in Columbia University Press, New York (1997), 631 Seiten. that groups together clades Pan-Carnivora and Pholidotamorpha. The Ferae is a sister group to the clade Pan-Euungulata and together they make grandorder Ferungulata. Classification and phylogeny Taxonomy : Phylogeny The phylogenetic relationships of mirorder Ferae are shown in the following cladogram, reconstructed from mitochondrial and nuclear DNA and protein characters, as well as the fossil record.O’Leary, M. A., Bloch JI, Flynn, J. J., Gaudin, T. J., Giallombardo, A., Giannini, N. P., Goldber, S. L, Kraatz, B. P., Luo, Z-X, Jin Meng, Xijun Ni, Novacek, M. J., Perini, F. A., Randall, Z. S., Rougier, G. W., Sargis, E. J., Silcox, M. T., Simmons, N. B., Spaulding, M. Velazco, P. M., Weksler, M., Wible, J. R. Cirranello, A. L. (2013."The Placental Mammal Ancestor an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odd-toed Ungulates
Odd-toed ungulates, mammals which constitute the taxonomic order Perissodactyla (, ), are animals—ungulates—who have reduced the weight-bearing toes to three (rhinoceroses and tapirs, with tapirs still using four toes on the front legs) or one (equines, third toe) of the five original toes. The non-weight-bearing toes are either present, absent, vestigial, or positioned posteriorly. By contrast, the even-toed ungulates bear most of their weight equally on four or two (an even number) of the five toes: their third and fourth toes. Another difference between the two is that odd-toed ungulates digest plant cellulose in their intestines rather than in one or more stomach chambers as even-toed ungulates, with the exception of Suina, do. The order includes about 17 species divided into three families: Equidae (horses, asses, and zebras), Rhinocerotidae (rhinoceroses), and Tapiridae (tapirs). Despite their very different appearances, they were recognized as related families i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evolution by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laurasiatheria
Laurasiatheria ("laurasian beasts") is a superorder of placental mammals that groups together true insectivores ( eulipotyphlans), bats ( chiropterans), carnivorans, pangolins ( pholidotes), even-toed ungulates (artiodactyls), odd-toed ungulates (perissodactyls), and all their extinct relatives. From systematics and phylogenetic perspectives, it is subdivided into order Eulipotyphla and clade Scrotifera. It is a sister group to Euarchontoglires with which it forms the magnorder Boreoeutheria. Laurasiatheria was discovered on the basis of the similar gene sequences shared by the mammals belonging to it; no anatomical features have yet been found that unite the group. The Laurasiatheria clade is based on DNA sequence analyses and retrotransposon presence/absence data. The superorder originated on the northern supercontinent of Laurasia, after it split from Gondwana when Pangaea broke up. Its last common ancestor is supposed to have diversified ca. 76 to 90 million years ago. Ety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artiodactyla
The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing posteriorly. By contrast, odd-toed ungulates bear weight on an odd number of the five toes. Another difference between the two is that many other even-toed ungulates (with the exception of Suina) digest plant cellulose in one or more stomach chambers rather than in their intestine as the odd-toed ungulates do. Cetaceans (whales, dolphins, and porpoises) evolved from even-toed ungulates, and are therefore often classified under the same taxonomic branch because a species cannot outgrow its evolutionary ancestry; some modern taxonomists combine the two under the name Cetartiodactyla , while others opt to include cetaceans in the already-existing Artiodactyla. The roughly 270 land-based even-toed ungulate species include pigs, peccaries, hippopo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Even-toed Ungulates
The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing posteriorly. By contrast, odd-toed ungulates bear weight on an odd number of the five toes. Another difference between the two is that many other even-toed ungulates (with the exception of Suina) digest plant cellulose in one or more stomach chambers rather than in their intestine as the odd-toed ungulates do. Cetaceans (whales, dolphins, and porpoises) evolved from even-toed ungulates, and are therefore often classified under the same taxonomic branch because a species cannot outgrow its evolutionary ancestry; some modern taxonomists combine the two under the name Cetartiodactyla , while others opt to include cetaceans in the already-existing Artiodactyla. The roughly 270 land-based even-toed ungulate species include pigs, peccaries, hippopota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eulipotyphla
Eulipotyphla (, which means "truly fat and blind") is an order of mammals suggested by molecular methods of phylogenetic reconstruction, which includes the laurasiatherian members of the now-invalid polyphyletic order Lipotyphla, but not the afrotherian members (tenrecs, golden moles, and otter shrews, now in their own order Afrosoricida). Eulipotyphla comprises the hedgehogs and gymnures (family Erinaceidae, formerly also the order Erinaceomorpha), solenodons (family Solenodontidae), the desmans, moles, and shrew-like moles (family Talpidae) and true shrews (family Soricidae). True shrews, talpids and solenodons were formerly grouped in Soricomorpha; however, Soricomorpha has been found to be paraphyletic, since erinaceids are the sister group of shrews, and they are more closely linked to the Carnivora order; (such as cats, dogs, bears, skunks, badgers, etc.). It is the sister clade of Scrotifera; together, they make up Laurasiatheria. Classification * Order Eulipoty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insectivora
The order Insectivora (from Latin ''insectum'' "insect" and ''vorare'' "to eat") is a now-abandoned biological grouping within the class of mammals. Some species have now been moved out, leaving the remaining ones in the order Eulipotyphla, within the larger clade Laurasiatheria, which makes up one of the most basic clades of placental mammals. History Before the era of widespread DNA sequencing, the grouping was used as a polyphyletic taxon for a variety of small to very small, relatively unspecialised mammals that feed upon insects. Since any primitive-looking fossil group of placental mammals was commonly assigned to this order for convenience, it was held to constitute the basal stock out of which other placental orders had evolved. Therefore, at its widest extent, the order Insectivora represented an evolutionary grade rather than a clade. Taxonomy has been refined in recent years, and treeshrews, elephant shrews, and colugos have now been placed in separate orders, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegasus
Pegasus ( grc-gre, Πήγασος, Pḗgasos; la, Pegasus, Pegasos) is one of the best known creatures in Greek mythology. He is a winged divine stallion usually depicted as pure white in color. He was sired by Poseidon, in his role as horse-god, and foaled by the Gorgon Medusa. He was the brother of Chrysaor, born at a single birthing when his mother was decapitated by Perseus. Greco-Roman poets wrote about his ascent to heaven after his birth and his obeisance to Zeus, king of the gods, who instructed him to bring lightning and thunder from Olympus (mythology), Olympus. Pegasus is the creator of Hippocrene, the fountain on Mount Helicon. He was captured by the Greek hero Bellerophon, near the fountain Pirene (fountain), Peirene, with the help of Athena and Poseidon. Pegasus allowed Bellerophon to ride him in order to defeat the monster Chimera (mythology), Chimera, which led to many more exploits. Bellerophon later fell from Pegasus's back while trying to reach Mount Olym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by Chicxulub impact, an asteroid impact and possibly volcanism, marked the beginning of the Paleocene and killed off 75% of living species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. In the Pal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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