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Octodontid
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 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Degu
The common degu (''Octodon degus''; ), or, historically, the degu, is a small hystricomorpha rodent endemic to the Chilean matorral ecoregion of central Chile. The name ''degu'' on its own indicates either the entire genus ''Octodon'' or, more commonly, just the common degu. Common degus belong to the parvorder Caviomorpha of the infraorder Hystricognathi, along with the chinchilla and guinea pig. The word ''degu'' comes from the indigenous language of Chile, Mapudungun, and the word ''dewü'', meaning 'mouse' or 'rat'. The animal may be kept as a pocket pet, though there are prohibitions on their ownership in some territories. As a pet, the animal is larger than a golden hamster but smaller than a fancy rat. Description The common degu is a small animal with a body length of and a weight of . It has yellow-brown fur above and creamy-yellow below, with yellow around the eyes and a paler band around the neck. It has a long, thin tail with a tufted, black tip, dark sparsely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octodon
''Octodon'' is a genus of octodontid rodents native to South America, in particular in the Chilean Andes. The best-known member is the common degu, ''O. degus'', which is kept as a pet in various countries. Two of the four species of degus are nocturnal.University of Michigan Classification This genus was first described in 1832 by the British zoologist Edward Turner Bennett.Taxonomy The genus name ''Octodon'' comes from the Latin ''octo'', eight, with reference to their teeth, molars and premolars having the shape of the number 8. The full list of species is: ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Degu
The common degu (''Octodon degus''; ), or, historically, the degu, is a small hystricomorpha rodent endemic to the Chilean matorral ecoregion of central Chile. The name ''degu'' on its own indicates either the entire genus ''Octodon'' or, more commonly, just the common degu. Common degus belong to the parvorder Caviomorpha of the infraorder Hystricognathi, along with the chinchilla and guinea pig. The word ''degu'' comes from the indigenous language of Chile, Mapudungun, and the word ''dewü'', meaning 'mouse' or 'rat'. The animal may be kept as a pocket pet, though there are prohibitions on their ownership in some territories. As a pet, the animal is larger than a golden hamster but smaller than a fancy rat. Description The common degu is a small animal with a body length of and a weight of . It has yellow-brown fur above and creamy-yellow below, with yellow around the eyes and a paler band around the neck. It has a long, thin tail with a tufted, black tip, dark sparsely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipanacoctomys
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] |
Ctenomyidae
A tuco-tuco is a neotropical rodent in the family Ctenomyidae.Parada, A., G. D’Elia, C.J. Bidau, and E.P. Lessa. 2011. Species Groups and the Evolutionary Diversification of Tuco-Tucos, genus ''Ctenomys'' (Rodentia: Ctenomyidae). ''Journal of Mammalogy'' 92(3): 671-682. Tuco-tucos belong to the only living genus of the family Ctenomyidae, ''Ctenomys'', but they include approximately 60 different species. The common name, "tuco-tuco" comes from the "tuc-tuc" sound they make while they dig their burrows.Anonymous. 2013. "Southern Tuco-tuco (''Ctenomys australis'')." ARKive. 04 Oct. 2013. http://www.arkive.org/southern-tuco-tuco/ctenomys-australis/ The relationships among the species are debated by taxonomists. It has been described that they are in a state of "taxonomic chaos", but banded karyotypes have been used to help make progress on their taxonomic study.Lessa, E. 1998. The Molecular Phylogenetics of Tuco-Tucos (genus ''Ctenomys'', Rodentia: Octodontidae) Suggests an Early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyploidy
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 mei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Viscacha Rat
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] |
Tuco-tuco
A tuco-tuco is a neotropical rodent in the family Ctenomyidae.Parada, A., G. D’Elia, C.J. Bidau, and E.P. Lessa. 2011. Species Groups and the Evolutionary Diversification of Tuco-Tucos, genus ''Ctenomys'' (Rodentia: Ctenomyidae). ''Journal of Mammalogy'' 92(3): 671-682. Tuco-tucos belong to the only living genus of the family Ctenomyidae, ''Ctenomys'', but they include approximately 60 different species. The common name, "tuco-tuco" comes from the "tuc-tuc" sound they make while they dig their burrows.Anonymous. 2013. "Southern Tuco-tuco (''Ctenomys australis'')." ARKive. 04 Oct. 2013. http://www.arkive.org/southern-tuco-tuco/ctenomys-australis/ The relationships among the species are debated by taxonomists. It has been described that they are in a state of "taxonomic chaos", but banded karyotypes have been used to help make progress on their taxonomic study.Lessa, E. 1998. The Molecular Phylogenetics of Tuco-Tucos (genus ''Ctenomys'', Rodentia: Octodontidae) Suggests an Early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Octodontomys
The mountain degu (''Octodontomys gliroides'') is a species of rodent in the family Octodontidae. It is the only species in the genus ''Octodontomys''. It is found in the foothills of the Andes in Argentina, Bolivia and Chile. Description The mountain degu is a moderate sized rodent with a length of , including a tail of , and a bodyweight in the range . The hairs are long and silky. The upper surface is greyish-brown, the chin is pure white, and the underparts are white with a grey base to the hairs. There is a tuft of white hair in front of the large ears, which are clad in short grey hair. The slender tail is bi-coloured (dark above and pale below) and has a tuft of brown or ochre hairs at the tip. Juveniles have darker fur above and greyer underparts. Their tails are brownish with a dark brown or black tufted tip. Distribution and habitat This species is found in the mountainous areas of southwestern Bolivia, northwestern Argentina and northern Chile. It has a wide altitudin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Florentino Ameghino
Florentino Ameghino (born Giovanni Battista Fiorino Giuseppe Ameghino September 19, 1853 – August 6, 1911) was an Argentine naturalist, paleontologist, anthropologist and zoologist, whose fossil discoveries on the Argentine Pampas, especially on Patagonia, rank with those made in the western United States during the late 19th century. Along with his two brothers –Carlos and Juan– Florentino Ameghino was one of the most important founding figures in South American paleontology. From 1887 until his death, Ameghino was passionately devoted to the study of fossil mammals from Patagonia, with the valuable support of his brother Carlos Ameghino (1865–1936) who, between 1887 and 1902, made 14 trips to that region, where he discovered and collected numerous fossil faunas and made important stratigraphic observations which helped to support his journal Ameghiniana. Biography Ameghino was born on September 19, 1853 in Tessi, an hamlet of Moneglia, a municipality of Liguria in Ita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagomorpha
The lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (hares and rabbits) and the Ochotonidae (pikas). The name of the order is derived from the Ancient Greek ''lagos'' (λαγώς, "hare") + ''morphē'' (μορφή, "form"). There are 110 recent species of lagomorph of which 109 are extant, including 34 species of pika, 42 species of rabbit, and 33 species of hare. Taxonomy and evolutionary history Other names used for this order, now considered synonymous, include: ''Duplicidentata'' - Illiger, 1811; ''Leporida'' - Averianov, 1999; ''Neolagomorpha'' - Averianov, 1999; ''Ochotonida'' - Averianov, 1999; and ''Palarodentia'' - Haeckel, 1895, Lilian, 2016. The evolutionary history of the lagomorphs is still not well understood. Until recently, it was generally agreed that '' Eurymylus'', which lived in eastern Asia and dates back to the late Paleocene or early Eocene, was an ancestor of the lagomorphs. More re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
