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Pennatomys
''Pennatomys nivalis'' is an extinct oryzomyine rodent from the islands of Sint Eustatius, Saint Kitts, and Nevis in the Lesser Antilles. The only species in the genus ''Pennatomys'', it is known from skeletal remains found in Amerindian archeological sites on all three islands, with dates ranging from 790–520BCE to 900–1200CE. No live specimens are known, but there are several historical records of rodents from Saint Kitts and Nevis that could conceivably refer to ''Pennatomys''. The animal apparently belongs to a group within the tribe Oryzomyini that includes many other island-dwelling species. ''Pennatomys nivalis'' was a medium-sized rodent without many distinctive adaptations. The nasal bones were short and blunt-ended. The zygomatic plate, a bony plate at the side of the skull, was broad. The bony palate was long and flat. The root of the lower incisor was housed in a bony protuberance, the capsular process. The molars were low-crowned and possess accessory crests suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oryzomyini
Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of the family Cricetidae. It includes about 120 species in about thirty genera,Weksler et al., 2006, table 1 distributed from the eastern United States to the southernmost parts of South America, including many offshore islands. It is part of the clade Oryzomyalia, which includes most of the South American Sigmodontinae. The name ''Oryzomyini'' derives from that of its type genus, ''Oryzomys'', which means "rice rat" or "rice mouse". Many species are also known as rice rats. Taxonomy Contents of Oryzomyini An oryzomyine group was first envisaged by Oldfield Thomas in the early 20th century. He defined it to include pentalophodont species, which have a mesoloph(id) on the upper and lower molars, with a long palate (extending past the third molars). Thomas included ''Oligoryzomys'', ''Oecomys'', and ''Oryzomys'' (which included many species now in other genera), as well as '' Rhagomys'', which is currently classified ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megalomys
''Megalomys'' is a genus of rodent in the family Cricetidae, part of the tribe Oryzomyini. The genus contains five large rodents from various Caribbean islands, of which two are known to have survived into modern times, but all of which are now extinct. The last species to survive was ''M. desmarestii'' from Martinique, which became extinct after the Mount Pelée eruption in 1902. Ancient DNA analysis places ''Megalomys'' forming a clade with '' Pennatomys,'' sister to the clade containing ''Aegialomys'', '' Nesoryzomys, Melanomys'' and ''Sigmodontomys,'' having diverged from the mainland clade around 7 million years ago. It contains the following species: Recently extinct species: * ''Megalomys desmarestii'' (Martinique giant rice rat) * ''Megalomys luciae'' (Saint Lucia giant rice rat) Fossil species: *''Megalomys audreyae'' (Barbuda giant rice rat) *'' Megalomys curazensis'' (Curaçao giant rice rat) *'' Megalomys georginae'' (Barbados Barbados is an island country i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanomys
''Melanomys'' is a genus of rodent in the tribe Oryzomyini of family Cricetidae, which is distributed in northern South America and adjacent Central America. It contains three species, two of which—'' Melanomys robustulus'' and '' Melanomys zunigae''—have limited distributions. The third, ''Melanomys caliginosus ''Melanomys caliginosus'', also known as the dusky melanomysMusser and Carleton, 2005 or dusky rice rat, is a species of rodent in the genus '' Melanomys'' of family Cricetidae. It is found from Central America, in Honduras, Nicaragua, Costa Rica ...'', is more widely distributed, but may be a species complex. References Rodent genera Taxa named by Oldfield Thomas Taxonomy articles created by Polbot {{Sigmodontinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigmodontomys
''Sigmodontomys'' is a genus of rodent in the tribe Oryzomyini of family Cricetidae. It is related to ''Nectomys'' and ''Melanomys'' and used to be included in ''Nectomys''. It includes two species, ''Sigmodontomys alfari'' and the much rarer ''Sigmodontomys aphrastus'', but whether these are indeed each other's closest relatives is uncertain.Weksler, 2006 References Literature cited *Musser, G.G. and Carleton, M.D. 2005. Superfamily Muroidea. Pp. 894–1531 in Wilson, D.E. and Reeder, D.M. (eds.)Mammal Species of the World: a taxonomic and geographic reference. 3rd ed Baltimore: The Johns Hopkins University Press, 2 vols., 2142 pp. *Weksler, M. 2006Phylogenetic relationships of oryzomyine rodents (Muroidea: Sigmodontinae): separate and combined analyses of morphological and molecular data Bulletin of the American Museum of Natural History 296:1–149. Sigmodontomys, Rodent genera Taxa named by Joel Asaph Allen Taxonomy articles created by Polbot {{Sigmodontina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nectomys
''Nectomys'' is a genus of rodent in the tribe Oryzomyini of family Cricetidae. Musser and Carleton, 2005. It is closely related to ''Amphinectomys'' and was formerly considered congeneric with ''Sigmodontomys''. It consists of five species, which are allopatrically distributed across much of South America: ''Nectomys grandis'' in montane Colombia; ''Nectomys palmipes'' on Trinidad and in nearby Venezuela, ''Nectomys apicalis'' in the western margins of the Amazon biome, ''Nectomys rattus'' in much of Amazonia, and ''Nectomys squamipes'' in the Atlantic Forest of Brazil. These species are generally semiaquatic In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below. Semiaquatic animals Semiaquatic animals include: * Verte ..., are normally found near water, and are commonly called water rats. Notes References Literature cited * Rodent g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphinectomys
''Amphinectomys savamis'', also known as the Ucayali water ratMusser and Carleton, 2005 or amphibious rat,Duff and Lawson, 2004 is a rodent from the Peruvian Amazon. It is placed as the only member of genus ''Amphinectomys'' in the tribe Oryzomyini of family Cricetidae. It is similar to ''Nectomys ''Nectomys'' is a genus of rodent in the tribe Oryzomyini of family Cricetidae. Musser and Carleton, 2005. It is closely related to '' Amphinectomys'' and was formerly considered congeneric with ''Sigmodontomys''. It consists of five species, whic ...'', but its discoverers considered it to be different enough (with more expansive interdigital webbing and a significantly broader interorbital region) to require its own genus. When it was described as a new genus in 1994, knowledge of the variation within ''Nectomys'' was much more limited than it is now, and it has been suggested that the status of the taxon be re-examined considering this new information. The species's karyotype, 2n = 5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegialomys
''Aegialomys'' is a genus of oryzomyini, oryzomyine rodents from the lowlands and mountains of western Peru and Ecuador, including the Galápagos Islands. The species in this genus have historically been placed in ''Oryzomys'', but according to cladistics, cladistic research, the genus is more closely related to a group containing, among others, ''Nectomys'' and ''Sigmodontomys'', than to ''Oryzomys''. The generic name ''Aegialomys'' means "coastal mouse" in Ancient Greek ( "coast" and "mouse") and references the mostly coastal occurrence of the genus. ''Aegialomys'' species have a greyish to buff dorsal pelage which is divided sharply from the white to light yellow ventral pelage. They have relatively short ears. There are crowns of hair at the bases of the toes. The tail is equal to or longer than the body and is darker above than below. There are two commonly recognized and described species in the genus: the mainland ''Aegialomys xanthaeolus, A. xanthaeolus'', the type speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between organisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (anatomy)
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Friedrich Burdach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladistic
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived characteristics ( synapomorphies'')'' that are not present in more distant groups and ancestors. However, from an empirical perspective, common ancestors are inferences based on a cladistic hypothesis of relationships of taxa whose character states can be observed. Theoretically, a last common ancestor and all its descendants constitute a (minimal) clade. Importantly, all descendants stay in their overarching ancestral clade. For example, if the terms ''worms'' or ''fishes'' were used within a ''strict'' cladistic framework, these terms would include humans. Many of these terms are normally used paraphyletically, outside of cladistics, e.g. as a 'grade', which are fruitless to precisely delineate, especially when including extinct species. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Name (zoology)
In zoological nomenclature, the specific name (also specific epithet or species epithet) is the second part (the second name) within the scientific name of a species (a binomen). The first part of the name of a species is the name of the genus or the generic name. The rules and regulations governing the giving of a new species name are explained in the article species description. For example, the scientific name for humans is ''Homo sapiens'', which is the species name, consisting of two names: ''Homo'' is the " generic name" (the name of the genus) and ''sapiens'' is the "specific name". Historically, ''specific name'' referred to the combination of what are now called the generic and specific names. Carl Linnaeus, who formalized binomial nomenclature, made explicit distinctions between specific, generic, and trivial names. The generic name was that of the genus, the first in the binomial, the trivial name was the second name in the binomial, and the specific the proper term for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
