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Toro (rodent)
The toros or brush-tailed rats, genus ''Isothrix'', are a group of spiny rats found in tropical South America, particularly in the Amazon Basin.Nowak, Ronald M. 1999. ''Walker's Mammals of the World'', 6th edition. Johns Hopkins University Press, 1936 pp. Description Toros look like large rats with soft fur on the body and long guard hairs on the scaly tail.Emmons, L.H. 2005. A Revision of the Genera of Arboreal Echimyidae (Rodentia: Echimyidae, Echimyinae), With Descriptions of Two New Genera. pp. 247–310 in Lacey, E.A. & Myers, P. 2005. Mammalian Diversification: From Chromosomes to Phylogeography (A Celebration of the Career of James L. Patton). University of California Publications in Zoology. Head and body is 18-27.5 cm and tail is 17–30 cm. Weight is 320-570 grams. Natural history These animals appear to be arboreal, based on the shape of their hind feet. They are thought to spend the day in holes in the ground near trees. Systematics The et ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing a faunal interchange between the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synonym (taxonomy)
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name (under the currently used system of scientific nomenclature) to the Norway spruce, which he called ''Pinus abies''. This name is no longer in use, so it is now a synonym of the current scientific name, '' Picea abies''. * In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refers to a taxon at that rank - for example, the name ''Papilio prorsa'' Linnaeus, 1758 is a junior synonym of ''Papilio levana'' Linnaeus, 1758, being names for different seasonal forms of the species now referred to as ''Araschnia l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isothrix
The toros or brush-tailed rats, genus ''Isothrix'', are a group of spiny rats found in tropical South America, particularly in the Amazon Basin.Nowak, Ronald M. 1999. ''Walker's Mammals of the World'', 6th edition. Johns Hopkins University Press, 1936 pp. Description Toros look like large rats with soft fur on the body and long guard hairs on the scaly tail.Emmons, L.H. 2005. A Revision of the Genera of Arboreal Echimyidae (Rodentia: Echimyidae, Echimyinae), With Descriptions of Two New Genera. pp. 247–310 in Lacey, E.A. & Myers, P. 2005. Mammalian Diversification: From Chromosomes to Phylogeography (A Celebration of the Career of James L. Patton). University of California Publications in Zoology. Head and body is 18-27.5 cm and tail is 17–30 cm. Weight is 320-570 grams. Natural history These animals appear to be arboreal, based on the shape of their hind feet. They are thought to spend the day in holes in the ground near trees. Systematics The e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphyletic
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly .. ource for pronunciation./ref> It is contrasted with monophyly and paraphyly. For example, the biological characteristic of warm-bloodedness evolved separately in the ancestors of mammals and the ancestors of birds; "warm-blooded animals" is therefore a polyphyletic grouping. Other examples of polyphyletic groups are algae, C4 photosynthetic plants, and edentates. Many taxonomists aim to avoid homoplasies in grouping taxa together, with a goal to identify and eliminate groups that are found to be polyphyletic. This is often the stimulus for major revisions of the classification schemes. Researchers concerned more with ecology than with syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myocastorini
Myocastorini is a tribe of echimyid rodents, proposed in 2017, and containing the five extant genera ''Callistomys'', ''Hoplomys'', ''Myocastor'', ''Proechimys'', and ''Thrichomys ''Thrichomys'' is a genus of South American rodents in the family Echimyidae. It contains at least five species, found in Bolivia, Brazil and Paraguay. They are as follows: * Common punaré (''Thrichomys apereoides'') * Foster's punaré (''Thrich ...''. Definition Myocastorini members share long upper incisor roots (except ''Callistomys''), and mid- to long-sized lower incisor roots. These five genera share either four (''Callistomys'', ''Thrichomys'') or five (''Hoplomys'', ''Myocastor'', ''Proechimys'') lophids on the lower deciduous fourth premolar, three roots anchoring the upper molars, and well-connected lophs on cheek teeth. Members display a variety of lifestyles including terrestrial (''Hoplomys'', ''Proechimys'', ''Thrichomys''), arboreal (''Callistomys''), and amphibious (''Myocastor'') ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callistomys Pictus
The painted tree-rat (''Callistomys pictus'') is a species of spiny rat from Brazil, restricted to north-eastern Bahia in eastern Brazil. It is the only species in the genus ''Callistomys''. Identification With a total length of ca. 30 cm (12 in), it is a relatively large species of spiny rat. It is white with a strongly contrasting glossy-black cap, back and band down towards its forelimbs. Its long fur is dense and coarse, but not spiny, as in some other members of its family. Specimens often have brown (rather than black) markings, but as far as it is known this is caused by fading and does not occur in the living animals. Owing to its striking black-and-white pelage, it is virtually unmistakable, but could perhaps be confused with a hairy dwarf porcupine ('' Coendou spp.'') – all of which have spines and lack the distinctive pattern of the painted tree-rat. Etymology * The genus name ''Callistomys'' derives from the two ancient greek words () meaning "very beau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echimyinae
Echimyinae is a subfamily of rodents belonging to the spiny rats family Echimyidae. It contains 14 arboreal genera—all the members of the tribe Echimyini, plus '' Callistomys''—a few terrestrial genera ('' Thrichomys'', '' Hoplomys'', and ''Proechimys''), and a subaquatic genus ('' Myocastor''). Systematics The taxonomic content of Echimyinae has been reshaped over time, because of two realizations. The first is a better understanding of the evolution of morphological characters, leading to the recognition that key character states long used to group genera into higher units were demonstrably homoplastic. The second came from the a phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ... analysis of molecular sequence data. Phylogeny The subfamily Echimyinae group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echimyini
Echimyini is a tribe of echimyid rodents, proposed in 2016, and containing 13 extant genera: all of the tree rats ''Echimys'', '' Phyllomys'', ''Makalata'', '' Pattonomys'', ''Toromys'', '' Diplomys'', '' Santamartamys'', and '' Isothrix'', the long recognized dactylomines '' Dactylomys'', '' Olallamys'', and '' Kannabateomys'', and the enigmatic and previously classified as eumysopines ''Lonchothrix'' and '' Mesomys''. All these spiny rats genera are arboreal. Worth of note, the arboreal genus '' Callistomys'' – the painted-tree rat – does not belong to the tribe Echimyini. Because it is phylogenetically closer to '' Myocastor'', '' Hoplomys'', ''Proechimys'', and '' Thrichomys'' than to the above-mentioned Echimyini genera, it is classified in the tribe Myocastorini. Phylogeny Five assemblages can be distinguished in the genus-level cladogram of Echimyini: * ''Echimys'' is closely related to ''Phyllomys'', ''Makalata'', ''Pattonomys'' and ''Toromys''. This clade is in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echimyidae Phylogeny
Echimyidae is the family of neotropical spiny rats and their fossil relatives. This is the most species-rich family of hystricognath rodents. It is probably also the most ecologically diverse, with members ranging from fully arboreal to terrestrial to fossorial to semiaquatic habits. They presently exist mainly in South America; three members of the family also range into Central America, and the hutias are found in the Greater Antilles in the Caribbean. Species of the extinct subfamily Heteropsomyinae formerly lived on Cuba, Hispaniola, and Puerto Rico in the Antilles, probably until the arrival of Europeans. Characteristics In general form, most spiny rats resemble rats, although they are more closely related to guinea pigs and chinchillas. Most species have stiff, pointed hairs, or spines, that presumably serve for protection from predators. Many echimyids can break off their tails when attacked. This action may confuse predators long enough for the spiny rat to esc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monophyly
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic groups are typically characterised by shared derived characteristics (synapomorphies), which distinguish organisms in the clade from other organisms. An equivalent term is holophyly. The word "mono-phyly" means "one-tribe" in Greek. Monophyly is contrasted with paraphyly and polyphyly as shown in the second diagram. A ''paraphyletic group'' consists of all of the descendants of a common ancestor minus one or more monophyletic groups. A '' polyphyletic group'' is characterized by convergent features or habits of scientific interest (for example, night-active primates, fruit trees, aquatic insects). The features by which a polyphyletic group is differentiated from others are not inherited from a common ancestor. These definitions have take ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Scientist
''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publishes a monthly Dutch-language edition. First published on 22 November 1956, ''New Scientist'' has been available in online form since 1996. Sold in retail outlets (paper edition) and on subscription (paper and/or online), the magazine covers news, features, reviews and commentary on science, technology and their implications. ''New Scientist'' also publishes speculative articles, ranging from the technical to the philosophical. ''New Scientist'' was acquired by Daily Mail and General Trust (DMGT) in March 2021. History Ownership The magazine was founded in 1956 by Tom Margerison, Max Raison and Nicholas Harrison as ''The New Scientist'', with Issue 1 on 22 November 1956, priced at one shilling (a twentieth of a pound in pre-decimal UK ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
