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Robust Tuco-tuco
The robust tuco-tuco (''Ctenomys tuconax'') is a species of rodent in the family Ctenomyidae. It is a burrowing rodent and is endemic to the Tucumán Province of Argentina. Description The robust tuco-tuco is a large species of tuco-tuco and grows to a total length of about including a tail of about . As is the case with other members of the genus, the eyes and ears are small, the fur is dense and the claws on the forefeet are large. The fur is brown and it has a blackish stripe running along its spine. The underparts are yellowish-brown and the tail pale brown. The feet are clad in sparse whitish hairs. Its karyotype has 2n = 58-61 and FN = 80. Distribution This tuco-tuco is endemic to Tucumán Province in northwestern Argentina where it lives at altitudes of up to . Its exact range is unclear but there seem to be two separate populations. It inhabits damp plains, making its burrows in well-compacted, humus-rich or loamy soils. Behaviour Tuco-tucos get their common na ... [...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] |
Data Deficient
A data deficient (DD) species is one which has been categorized by the International Union for Conservation of Nature (IUCN) as offering insufficient information for a proper assessment of conservation status to be made. This does not necessarily indicate that the species has not been extensively studied; but it does indicate that little or no information is available on the abundance and distribution of the species. The IUCN recommends that care be taken to avoid classing species as "data deficient" when the absence of records may indicate dangerously low abundance: "If the range of a taxon is suspected to be relatively circumscribed, if a considerable period of time has elapsed since the last record of the taxon, threatened status may well be justified""The Categories," in IUCN (1983). (see also precautionary principle). See also * IUCN Red List data deficient species * List of data deficient amphibians * IUCN Red List data deficient species (Annelida) * List of data deficien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals Described In 1925
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 with Sauropsida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Fauna Of Argentina
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals Of The Andes
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 with Sauropsida ... [...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] |
Tuco-tucos
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] |
Vulnerable Species
A vulnerable species is a species which has been Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, threatening its survival and reproduction improve. Vulnerability is mainly caused by habitat loss or destruction of the species' home. Vulnerable habitat or species are monitored and can become increasingly threatened. Some species listed as "vulnerable" may be common in captivity (animal), captivity, an example being the military macaw. There are currently 5196 animals and 6789 plants classified as Vulnerable, compared with 1998 levels of 2815 and 3222, respectively. Practices such as cryoconservation of animal genetic resources have been enforced in efforts to conserve vulnerable breeds of livestock specifically. Criteria The International Union for Conservation of Nature uses several criteria to enter species in this category. A tax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union For Conservation Of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fundamental Number
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] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, whose i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and 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, tissues, and 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 polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an organism's life cycle. Half ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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