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Necromys Lilloi
''Necromys'' is a genus of South American sigmodontine rodents allied to ''Akodon''. This genus has also been known as ''Cabreramys'' or more recently ''Bolomys'', and the northern grass mouse (''N. urichi'') has recently been transferred from ''Akodon''. History Most of the Brazilian members of the genus ''Necromys'' were first described in the second half of the nineteenth century, and the species from the Andes followed in the first decades of the twentieth century. Small rodents in South America were studied by the British zoologist Oldfield Thomas, curator at the Natural History Museum, London who erected the genus ''Bolomys'' in 1916. Characteristics Members of the genus ''Necromys'' are spread out over a wide area of Central and South America. Morphologically, members of the genus are difficult to distinguish from two other genera found in the same region, the grass mice ''Akodon'' and the cane mice ''Zygodontomys''. In 1987, the Argentine zoologist Osvaldo Reig liste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Neogene Period in the . The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akodon
''Akodon'' is a genus consisting of South American grass mice. They mostly occur south of the Amazon Basin and along the Andes north to Venezuela, but are absent from much of the basin itself, the far south of the continent, and the lowlands west of the Andes. ''Akodon'' is one of the most species-rich genera of Neotropical rodents. Species of ''Akodon'' are known to inhabit a variety of habitats from tropical and tropical moist forests to altiplano and desert. Fossils are known from the late Pliocene onwards. Taxonomy ''Akodon'' is the largest genus in the tribe Akodontini. Three of its synonyms—''Chalcomys'', ''Hypsimys'', and particularly ''Microxus''—have sometimes been regarded as distinct genera. Neomicroxus was separated in 2013. Previously associated with ''Akodon'', the genera ''Abrothrix'', '' Deltamys'', ''Necromys'', ''Thalpomys'', and '' Thaptomys'' are currently recognized as distinct. Some species of the tribe Abrotrichini are called akodons. The genus cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spotted Bolo Mouse
The spotted bolo mouse or Ecuadorian akodont (''Necromys punctulatus'') is a species of rodent in the family Cricetidae. It is known from Ecuador and may also occur in Colombia. Little is known of its status and range. Taxonomy ''Necromys punctulatus'' is known from a single specimen in the Natural History Museum, London which was originally collected by the British zoologist Louis Fraser in Ecuador between 1857 and 1859. For a long time this was thought to be a subspecies of the short-tailed cane mouse (''Zygodontomys brevicauda'') but in 1991, the American zoologist Robert S. Voss examined the type specimen and came to the conclusion that it had many features in common with the hairy-tailed bolo mouse (''Necromys lasiurus''), then classified as ''Bolomys lasiurus'', and placed it in the same genus, as ''Bolomys punctata''. Both have since been transferred to the new genus ''Necromys''. Description The spotted bolo mouse is a medium-sized member of its genus, growing to a total ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Bolo Mouse
The dark bolo mouse or dark-furred akodont (''Necromys obscurus'') is a species of rodent in the family Cricetidae. There are two subspecies; one (ssp. ''scagliarum'') is found in eastern and central parts of Buenos Aires Province, Argentina, and the other (ssp. ''obscurus'') in coastal areas of southern Uruguay. Description The dark bolo mouse is the largest species in the genus, with a head-and-body length of about and a tail length of . The fur is fairly long and glossy. The dorsal surface is dark brown to brownish-black, the individual hairs having black bases and tips and pale central portions, giving the pelage an "agouti" appearance. The cheeks and flanks are tinged with orange or buff and the underparts are greyish, the hairs having yellowish tips. The tail is deep brown above and grey underneath, and the upper surfaces of the hands are dark, with dark fur mixed with some buff hairs on the feet. Distribution and habitat The dark bolo mouse is found in two separate locat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Necromys Lilloi
''Necromys'' is a genus of South American sigmodontine rodents allied to ''Akodon''. This genus has also been known as ''Cabreramys'' or more recently ''Bolomys'', and the northern grass mouse (''N. urichi'') has recently been transferred from ''Akodon''. History Most of the Brazilian members of the genus ''Necromys'' were first described in the second half of the nineteenth century, and the species from the Andes followed in the first decades of the twentieth century. Small rodents in South America were studied by the British zoologist Oldfield Thomas, curator at the Natural History Museum, London who erected the genus ''Bolomys'' in 1916. Characteristics Members of the genus ''Necromys'' are spread out over a wide area of Central and South America. Morphologically, members of the genus are difficult to distinguish from two other genera found in the same region, the grass mice ''Akodon'' and the cane mice ''Zygodontomys''. In 1987, the Argentine zoologist Osvaldo Reig liste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraguayan Bolo Mouse
The Paraguayan bolo mouse or Paraguayan akodont (''Necromys lenguarum'') is a species of rodent in the family Cricetidae. According to the IUCN, it is present in Bolivia, Paraguay, and Peru, and possibly also in Argentina and Brazil. It is found at elevations from in a variety of habitats, including cerrado, chaco, and heath pampas. Taxonomy The taxonomic status of this species is unclear. It was at one time thought to be a subspecies of the dark bolo mouse ''N. obscurus'', and some authorities consider it to be a synonym of '' N. lasiurus''. Mitochondrial DNA analysis supports it being a species in its own right, but the precise range occupied by each species has not been elucidated. Description The Paraguayan bolo mouse is a medium-sized species, being about long including a tail of . The upper surface of head and body is dark grey, and the rump ochre-grey. The flanks are paler and the underparts are white, sometimes with a yellowish tinge. The tail is black above and white ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rufous-bellied Bolo Mouse
The rufous-bellied bolo mouse or white-chinned akodont, (''Necromys lactens'') is a species of rodent in the family Cricetidae. It is found in Argentina and Bolivia where it inhabits the dry valleys of the eastern Andes. Its conservation status is listed by the International Union for Conservation of Nature as being of "least concern". Description The rufous-bellied bolo mouse reaches a head-and-body length of with a tail of . The head and back are a buffy-brown with fine streaks of black. The flanks are more richly coloured, reddish-brown or cinnamon, and the underparts are a variable shade of cinnamon. The ears are well-haired and there is nearly always a white spot on the chin or throat. The tail is two-coloured, blackish brown above and whitish or buff below. The claws are long and are concealed in tufts of white hair. Distribution and habitat The rufous-bellied bolo mouse is native to the eastern slopes of the Andes in central and southern Bolivia and northern Argentina. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argentine Bolo Mouse
The Argentine bolo mouse (''Necromys benefactus'') is a species of rodent in the family Cricetidae. It is endemic to central Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ..., where it is found in the pampas and the drier espinal (lowland thorn brush). References Mammals of Argentina Necromys Endemic fauna of Argentina Mammals described in 1919 Taxa named by Oldfield Thomas {{Sigmodontinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleasant Bolo Mouse
The pleasant bolo mouse, or pleasant akodont, (''Necromys amoenus'') is a species of rodent in the family Cricetidae. It is found on grassland at high altitudes in Bolivia and Peru. Description The pleasant bolo mouse is a small member of its genus with a head-and-body length of between and a tail of . The back and upper parts have yellowish-brown fur intermixed with some black hairs. The muzzle, cheeks and sides of the body are yellowish-buff, and the underparts are whitish. There is often a clear demarcation between the different regions, and the belly contrasts strongly with the upper regions. The whiskers are short, the ears rounded and well-furred and the tail is blackish-brown or ochre-brown above, and white below. The paws are covered with ochre-brown hairs above and the nails are concealed in bushy tufts of hair. Distribution and habitat The pleasant bolo mouse is found in the Andean Plateau of west-central South America, in western Bolivia and southeastern Peru. It is p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ploidy
Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, Tissue (biology), tissues, and Individual#Biology, individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploidy, polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexual reproduction, sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities. A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are organized in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotyping generally combines light microscopy and photography, and results in a photomicrographic (or simply micrographic) karyogram. In contrast, a schematic karyogram is a designed graphic representation of a karyotype. In schematic karyograms, just one of the sister chromatids of each chromosome is generally shown for brevity, and in reality they are generally so close together that they look as one on photomicrographs as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osvaldo Reig
Osvaldo Alfredo Reig, (14 August 1929 – 13 March 1992), was an Argentine biologist and paleontologist. He was born in Buenos Aires, Argentina. He made numerous contributions in the fields of paleontology and biological evolution. He studied at the Universidad de La Plata, but did not complete his studies. Later he worked at the University of Buenos Aires in the Department of Biological Sciences working with the biological evolution of mammals. In 1966 he began work at the Museum of Comparative Zoology at Harvard University. He worked for almost fifteen years at the Central University of Venezuela and the Simón Bolívar University. In 1973 he received his PhD in Zoology and Paleontology from the University of London. Among the important papers he authored was the description of ''Herrerasaurus'', one of the earliest dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
