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Oligoryzomys
''Oligoryzomys'' is a genus of rodents in the tribe Oryzomyini of family Cricetidae. Many species are known as pygmy rice rats or colilargos.Musser and Carleton, 2005 The genus is found from Mexico to Tierra del Fuego and includes approximately 17 species. In Argentina and Chile, ''Oligoryzomys longicaudatus'' and other members of the genus represent the reservoir for the hantavirus strain Andes virus (ANDV) (Wells et al., 1997; Levis et al., 1998; Cantoni et al., 2001). Taxonomy The genus ''Oligoryzomys'' is included in the subfamily Sigmodontinae of the family Cricetidae. The genus is placed in the Oryzomyini tribe, first proposed by Oldfield Thomas in the early 20th century. It includes genera that have certain dental features of the upper and lower molars and a long palate which extends past the third molars. More recently, molecular analysis and morphological data has placed the genus in Clade C, alongside ''Neacomys'', ''Microryzomys'' and ''Oreoryzomys''. Characteristics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Nigripes
''Oligoryzomys nigripes'', also known as the black-footed colilargo or the black-footed pygmy rice rat, is a rodent in the genus ''Oligoryzomys'' of family Cricetidae. Oligoryzomys nigripes is a species that has been further divided into different sister taxa throughout history. It is found in different countries in South America.Weksler, M. & Bonvicino, C.R. 2005. Taxonomy of pygmy rice rats genus ''Oligoryzomys'' Bangs, 1900 (Rodentia, Sigmodontinae) of the Brazilian Cerrado, with the description of two new species. Arquivos do Museu Nacional 63(1):119. It is a large species with long ears, dark yellow to dark brown upperparts, sharply delimited from the whitish underparts, and often a pink girdle on the chest. This species of rat spends much of its life among the trees. The karyotype is 2n = 62, FNa = 78–82. Synonym species Two other species, '' Oligoryzomys delticola'' (also known as the delta pygmy rice rat or the large colilargo) and '' Oligoryzomys eliurus'' (also kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigmodontinae
The rodent subfamily Sigmodontinae includes New World rats and mice, with at least 376 species. Many authorities include the Neotominae and Tylomyinae as part of a larger definition of Sigmodontinae. When those genera are included, the species count numbers at least 508. Their distribution includes much of the New World, but the genera are predominantly South American, such as brucies. They invaded South America from Central America as part of the Great American Interchange near the end of the Miocene, about 5 million years ago. Sigmodontines proceeded to diversify explosively in the formerly isolated continent. They inhabit many of the same ecological niches that the Murinae occupy in the Old World. The "Thomasomyini" from the Atlantic Forest of Brazil are generally thought to be not especially related to the "real" Thomasomyini from the northern Andes and the Amazon rainforest. The genera ''Wiedomys'' and '' Sigmodon'' are generally placed in their own tribe, and the "phyll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Victus
''Oligoryzomys victus'', also known as the St. Vincent colilargo or St. Vincent pygmy rice rat, is a species of rodent in the genus ''Oligoryzomys'' of the oryzomyine tribe. Only one specimen is known, which was collected on Saint Vincent in the Lesser Antilles in about 1892, and it is now presumed extinct. Taxonomy The only known specimen was collected by H. H. Smith at an unknown location on Saint Vincent and later presented to the British Museum of Natural History, where it was registered as specimen BMNH 97.12.26.1. In 1898, Oldfield Thomas described the specimen as the holotype of a new species of ''Oryzomys'' which he named ''Oryzomys victus''. Although Thomas placed it close to species now placed in ''Oligoryzomys'', later compilators considered the affinities of ''O. victus'' as unknown; one study placed it in the ''Oryzomys tectus'' group (more or less = ''Oecomys''). In his 1962 study of Antillean oryzomyines, however, American paleontologist Clayton Ray reaffirmed its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Rupestris
''Oligoryzomys rupestris'' is a species of rodent in the genus ''Oligoryzomys'' of family Cricetidae. It is known only from eastern Brazil, where it has been found in several localities in the campos rupestres montane savanna ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of .... This is a small ''Oligoryzomys'' species with a gray head, a yellow-brown back and gray belly and tail. Of the two karyotypic forms described by Silva & Yonenaga-Yassuda in 1998, species 1 is probably identical to ''O. rupestris'', while the other (species 2) is closely related. Its karyotype has 2n = 46 and FNa = 52. References Mammals of Brazil Oligoryzomys Mammals described in 2005 Taxa named by Marcelo Weksler {{Oligoryzomys-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Microtis
''Oligoryzomys microtis'', also known as the small-eared colilargo or small-eared pygmy rice rat, is a species of rodent in the genus ''Oligoryzomys'' of family Cricetidae. It is found in western Brazil, eastern Peru, Bolivia, and northern Paraguay. Description ''Oligoryzomys microtis'' has a total length of including a tail of . It weighs about and is the smallest species in the genus. In proportion to the head and body length, the hind feet are relatively long, being 28.5% of their length. This compares with the rather similar ''Oligoryzomys nigripes ''Oligoryzomys nigripes'', also known as the black-footed colilargo or the black-footed pygmy rice rat, is a rodent in the genus ''Oligoryzomys'' of family Cricetidae. Oligoryzomys nigripes is a species that has been further divided into differen ...'' where the proportion is 24.5%. The ears are small and densely furred inside. The cheeks may be grey or orangeish-brown. The back is brownish and the underparts are whitish or gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Vegetus
''Oligoryzomys vegetus'', also known as the sprightly colilargoMusser and Carleton, 2005 or sprightly pygmy rice rat, is a species of rodent in the genus ''Oligoryzomys'' of family Cricetidae. It is found only in the mountains of Costa Rica and western Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos .... References Literature cited * *Timm, R. and Woodman, N. 2008. . In IUCN. IUCN Red List of Threatened Species. Version 2009.2.www.iucnredlist.org. Downloaded on November 28, 2009. Oligoryzomys Mammals described in 1902 Taxonomy articles created by Polbot {{Oligoryzomys-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Stramineus
''Oligoryzomys stramineus'', also known as the straw-colored colilargo or straw-colored pygmy rice rat,Duff and Lawson, 2004 is a species of rodent in the genus ''Oligoryzomys'' of the family Cricetidae. It occurs only in the cerrado and caatinga ecoregions of northeastern Brazil. Its karyotype has 2n = 52 and FNa = 68-70. Description ''Oligoryzomys stramineus'' is a large species of colilargo with a yellowish-brown head and dorsal surface and whitish underparts, with a sharp line demarcating the boundary between the two. It has long incisive foramina (openings in the hard palate of the skull) and broad zygomatic plates (bony plates in the upper jaw). The head-and-body length averages while the tail averages . Distribution and habitat This species is native to South America where it occurs in northeastern and central Brazil. Its range extends from the cerrado ecoregion of the states of northern Goiás and northern Minas Gerais southward to the caatinga ecoregion of the states o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Magellanicus
''Oligoryzomys magellanicus'', also known as the Patagonian colilargo and the Magellanic pygmy rice rat, is a species of rodent in the genus ''Oligoryzomys'' of the family Cricetidae. It is found in the southernmost parts of Argentina and Chile, including Tierra del Fuego and other outlying islands. Its karyotype has 2n = 54 and FNa = 66. Taxonomy There has been discussion as to whether ''Oligoryzomys magellanicus'' should be regarded as a full species or whether it should be considered to be a subspecies of ''Oligoryzomys longicaudatus''. Milton H. Gallardo and Eduardo Palma (1990) recognised it as a valid species, basing their findings on "phallic morphology and karyotypic and morphometric data". Description The Magellanic pygmy rice rat has a head-and-body length about equal to the length of its tail. The ears are moderately large, and are rounded with hairs on both surfaces. The dorsal pelage is greyish-buff and the underparts are whitish. The upper surface of both fore and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Fulvescens
''Oligoryzomys fulvescens'', also known as the fulvous colilargo,Musser and Carleton, 2005 fulvous pygmy rice rat, or northern pygmy rice rat,Duff and Lawson, 2004 is a species of rodent in the genus ''Oligoryzomys'' of family Cricetidae. It is found from southern Mexico through Central America into South America, where it occurs south into Peru and Brazil, and includes numerous synonyms, including the type species of the genus, ''Oryzomys navus'' Bangs, 1899. The taxonomy of this species is unresolved, and it may be found to contain more than one species. Its karyotype A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is disce ... has 2n = 54-60 and FNa = 68–74. References Literature cited *Duff, A. and Lawson, A. 2004. Mammals of the World: A checklist. New Haven: A & C Black. . * *Weks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Longicaudatus
''Oligoryzomys longicaudatus'', also known as the long-tailed colilargo or long-tailed pygmy rice rat, is a species of rodent in the genus '' Oligoryzomys'' of the family Cricetidae. It is found in the southern Andes of Chile and Argentina, with an outlying population in eastern Argentina. As a common species with a wide range and a stable population, the International Union for Conservation of Nature has rated this rodent as being of "least concern". Description ''O. longicaudatus'' grows to a total length of , including a tail of , and weighs about . The ears are quite small and are scantily clad with hairs. The tail is also scantily haired and is dark above and pale on the underside. The fur on the back is buff with fine pale brown and black lines, the greyish base of the hairs sometimes being visible. The underparts are greyish-white. The tail is shorter at the southern end of the range, and in Argentina, the fur is tinted with ochre, especially on the flanks. Its karyotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Destructor
''Oligoryzomys destructor'', also known as Tschudi's colilargoMusser and Carleton, 2005 or the destructive pygmy rice rat, is a species of rodent in the genus ''Oligoryzomys'' of family Cricetidae. It is found along the eastern Andes from southern Colombia, through Ecuador, Peru, and Bolivia into northern Argentina. Its karyotype has 2n = 60 and FNa = 76. Description ''Oligoryzomys destructor'' is a small species of rice rat. The head is reddish-brown with many blackish hairs, and just behind the ears there are pale patches. The ears have short, pale brown hairs on the inside and longer, blackish hairs on the outside. The whiskers are black with white tips and the hairs at the end of the snout are white. The fur on the dorsal surface of the body is reddish-brown, interspersed with black hairs, and a few grey hairs with pale tips. The flanks are reddish-brown, the throat and chest are pale grey and the belly is yellowish-white. The tail is brown and slightly shorter than the com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoryzomys Flavescens
''Oligoryzomys flavescens'', also known as the flavescent colilargo or yellow pygmy rice rat is a species of rodent in the genus ''Oligoryzomys'' of family Cricetidae. It is found in southern South America, occurring in southern Brazil, Paraguay, Uruguay, and northeastern Argentina. Its karyotype has 2n = 64-66 and FNa = 66-70. Description The dorsal fur of ''Oligoryzomys flavescens'' consists of bright orangish-brown hairs mixed with blackish hairs, the hairs on the flanks are all orange and the underparts are yellowish-grey. The boundary between the upper parts and the underparts is indistinct, grading from one colour to the other. The head-and-body length averages and the tails averages . Skull features that distinguish this species include the long incisive foramina (openings in the hard palate) that usually reach the first molar, and the short mesopterygoid fossa (a depression behind the end of the palate) which does not extend as far as the third molar. Distribution ''O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
