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Octomys
The mountain viscacha rat or mountain vizcacha rat (''Octomys mimax''), historically viscacha rat or vizcacha rat, is a species of rodent in the family Octodontidae. It is endemic to Argentina. It is the only living species within the genus ''Octomys''. This diploid genus (2n = 56) may be ancestral to the two unusual suspected tetraploid species ''Tympanoctomys barrerae'' and ''Pipanacoctomys aureus''. However, some genetic studies have rejected any polyploidism in mammals as unlikely, and suggests that ''amplification and dispersion of repetitive sequences best explain the large genome size''. Description The mountain viscacha rat is a rat-like animal with a head-body length of about and weighing from . The feet are relatively long, while the tail measures . It has light brown fur with white underparts and a bushy tail. Unusual features of the viscacha rat include greatly enlarged auditory bullae, and the presence of numerous whiskers on the roof of the mouth behind the inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octodontidae
Octodontidae is a family of rodents, restricted to southwestern South America. Fourteen species of octodontid are recognised, arranged in seven genera. The best known species is the common degu, ''Octodon degus''. Octodontids are medium-sized rodents, ranging from in body length. They have long, silky, fur, which is typically brownish in color, and often paler on the underside. The name 'octodont' derives from the wear pattern of their teeth, which resembles a figure 8. Most are nocturnal, social, burrowing animals, though the degu is largely diurnal. They are herbivorous, eating tubers, bulbs, and cactuses. Some authors have suggested that the octodontids should be reclassified in the order Lagomorpha, but this has not been supported by further analyses. Older literature includes the tuco-tucos in the family, as the subfamily Ctenomyinae, but these animals are normally now treated as a separate family, Ctenomyidae. There is some evidence that evolution within the family ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tympanoctomys Barrerae
The plains viscacha rat, plains vizcacha rat, red viscacha rat, or red vizcacha rat (''Tympanoctomys barrerae'') is a species of rodent in the family Octodontidae native to Argentina. It is one of three species in the genus ''Tympanoctomys''. Description The plains viscacha rat is a moderately-sized rat, with a large head, long tail, and short ears. Adults measure about in total length, with a tail, and weigh an average of , with males being slightly larger than females. The rat has buff-yellow fur with white underparts, fading to dark brown at the tip of the tail. Distribution and habitat The plains viscacha rat is endemic to central western Argentina, where it has a fragmented range in Mendoza Province and western La Pampa. Its natural habitat is desert scrubland, dunes and salt flats, between . There are no recognised subspecies. The species is threatened by destruction of its fragmented and restricted habitat. Biology and behaviour Plains viscacha rats are solitary, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei ( eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains one or more chromosomes and comes from each of two parents, resulting in pairs of homologous chromosomes between sets. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals Of Argentina
This is a list of the native mammal species recorded in Argentina. As of January 2020, the list contains 402 mammal species from Argentina, of which one is extinct, seven are critically endangered, seventeen are endangered, sixteen are vulnerable, and thirty are near threatened. The following tags are used to highlight each species' conservation status as assessed by the International Union for Conservation of Nature; those on the left are used here, those in the second column in some other articles: Subclass: Theria Infraclass: Metatheria Superorder: Ameridelphia =Order: Didelphimorphia (common opossums)= ---- Didelphimorphia is the order of common opossums of the Western Hemisphere. Opossums probably diverged from the basic South American marsupials in the late Cretaceous or early Paleocene. They are small to medium-sized marsupials, about the size of a large house cat, with a long snout and prehensile tail. *Family: Didelphidae (American opossums) **Subfamily: Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oldfield Thomas
Michael Rogers Oldfield Thomas (21 February 1858 – 16 June 1929) was a British zoologist. Career Thomas worked at the Natural History Museum on mammals, describing about 2,000 new species and subspecies for the first time. He was appointed to the museum secretary's office in 1876, transferring to the zoological department in 1878. In 1891, Thomas married Mary Kane, daughter of Sir Andrew Clark, heiress to a small fortune, which gave him the finances to hire mammal collectors and present their specimens to the museum. He also did field work himself in Western Europe and South America. His wife shared his interest in natural history, and accompanied him on collecting trips. In 1896, when William Henry Flower took control of the department, he hired Richard Lydekker Richard Lydekker (; 25 July 1849 – 16 April 1915) was an English naturalist, geologist and writer of numerous books on natural history. Biography Richard Lydekker was born at Tavistock Square in London. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipanacoctomys Aureus
The golden viscacha rat or golden vizcacha rat (''Pipanacoctomys aureus'') is the single species of the genus ''Pipanacoctomys'' of the rodent family Octodontidae. It has 92 chromosomes and has been regarded as tetraploid ( 4x = 2n).Gallardo, M. H. ''et al.'' (2004).Whole-genome duplications in South American desert rodents (Octodontidae). ''Biological Journal of the Linnean Society, 82'', 443-451. This octodontid and its sister-species, the plains viscacha rat (''Tympanoctomys barrerae'') (2n = 102), may have arisen from the diploid mountain viscacha rat (''Octomys mimax''), (2x = 2n = 56) as a result of the doubling and subsequent loss of some chromosomes. However, some genetic studies have rejected any polyploidism in mammals as unlikely, and suggest that amplification and dispersion of repetitive sequences best explain the large genome size. Description The golden viscacha rat grows to a head-and-body length of about with a tufted tail of about . The dorsal fur is golden-bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viscacha Rat (other)
Viscacha rats are a group of rodents in the family Octodontidae. All species are found in Argentina. They are placed in the following genera: *Genus ''Octomys'' ** ''O. mimax '', mountain viscacha rat, found in the Andes *Genus ''Pipanacoctomys'' ** ''P. aureus'', the golden viscacha rat, found near a salt flat *Genus ''Tympanoctomys'' (4 species, 3 extant), found in desert shrubland near salt flats ** ''T. barrerae'', the plains viscacha rat ** ''T. kirchnerorum'', Kirchner's viscacha rat Kirchner's viscacha rat or Kirchner's vizcacha rat (''Tympanoctomys kirchnerorum'') is a species of rodent in the family Octodontidae described in 2014. It is one of two species in the genus ''Tympanoctomys''. That species is endemic to Chubut Pr ..., ** ''T. loschalchalerosorum'', the Chalchalero viscacha rat ** †'' T. cordubensis'' {{disambiguation Rodents Animal common name disambiguation pages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals Of Chile
Mammals () are a group of vertebrate animals constituting the class (biology), class Mammalia (), characterized by the presence of mammary glands which in Female#Mammalian female, females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three ossicles, middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they Genetic divergence, diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant taxon, extant species of mammals have been described divided into 29 Order (biology), orders. The largest Order (biology), orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, Mole (animal), 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, pinniped, seals, and others). In terms of cladistic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight. Some animals, such as cats and ferrets, have eyes that can adapt to both low-level and bright day levels of illumination (see metaturnal). Others, such as bushbabies and (some) bats, can function only at night. Many nocturnal creatures including tarsiers and some owls have large eyes in comparison with their body size to compensate for the lower light levels at night. More specifically, they have been found to have a larger cornea relative to their eye size than diurnal creatures to increase their : in the low-light conditions. Nocturnality helps wasps, such as ''Apoica flavissima'', avoid hunting in intense sunlight. Diurnal animals, including squirrels and songbirds, are active du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals Described In 1920
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 w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boxthorn
''Lycium'' is a genus of flowering plants in the nightshade family, Solanaceae. The genus has a disjunct distribution around the globe, with species occurring on most continents in temperate and subtropical regions. South America has the most species, followed by North America and southern Africa. There are several scattered across Europe and Asia, and one is native to Australia.Fukuda, T., et al. (2001)Phylogeny and biogeography of the genus ''Lycium'' (Solanaceae): Inferences from chloroplast DNA sequences. ''Molecular Phylogenetics and Evolution'' 19(2), 246-58. Common English names for plants of this genus include box-thorn''Lycium''. The Jepson eFlora 2013. and desert-thorn. There are about 70 to 80 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maytenus
''Maytenus'' ''Sunset Western Garden Book,'' 1995:606–607 is a genus of flowering plants in the family Celastraceae. Members of the genus are distributed throughout Central and South America, Southeast Asia, Micronesia and Australasia, the Indian Ocean and Africa. They grow in a very wide variety of climates, from tropical to subpolar. The traditional circumscription of ''Maytenus'' is paraphyletic, so many species have been transferred to ''Denhamia ''Denhamia'' is a genus of plants within the family Celastraceae, with species in Australia and New Caledonia. The species inhabit a variety of environments, from rainforest to semi-arid savanna. All species grow as shrubs or small trees up to 10 ...'', ''Gymnosporia'', ''Monteverdia'', and ''Tricerma''. Selected species * ''Maytenus abbottii'' Abraham Erasmus van Wyk, A.E.van Wyk * ''Maytenus acuminata'' (L.f.) Loes. * ''Maytenus boaria'' Juan Ignacio Molina, Molina (type species) * ''Maytenus buxifolia'' (A.Rich.) Griseb. (West ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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