''Nephelomys nimbosus'' is a species of

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 na ...

in the genus ''

Nephelomys ''Nephelomys'' is a genus of South American oryzomyine rodents found in the Andes from Bolivia to Venezuela, with a westward extension into the mountains of Costa Rica. Its generic name is derived from the Ancient Greek word ''nephelê'' "mist", ...

'' of family

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and has m ...

.Weksler et al., 2006, p. 18 Its type locality is at San Antonio on the northeastern slope of the

Tungurahua Tungurahua (; from Quichua ''tunguri'' (throat) and ''rahua'' (fire), "Throat of Fire")) is an active stratovolcano located in the Cordillera Oriental of Ecuador. The volcano gives its name to the province of Tungurahua. Volcanic activity resta ...

in the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

, at an altitude of about . The

type series In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...

included five individuals.Anthony, 1926, p. 4 The fur of the upperparts is brown to blackish, becoming lighter towards the sides. The underparts are grayish, with a white patch at the throat. The long tail virtually lacks hairs and is darker above than below. In the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, the total length is , the head and body length is , the combined length of the tail

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

e is , the hindfoot length (including claws) is , and the length of the skull is . In most species of ''Nephelomys'', the

posterolateral palatal pits In anatomy, posterolateral palatal pits are gaps at the sides of the back of the bony palate, near the last molars.Weksler, 2006, p. 34 Posterolateral palatal pits are present, in various degrees of development, in several members of the roden ...

, perforations of the

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sepa ...

near the third molar, are conspicuous and receded into a depression or fossa, but in ''N. nimbosus'' and '' N. caracolus'', they are much smaller. It was first described, in 1926, by American zoologist H. E. Anthony as a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of '' Oryzomys auriventer''. It is smaller than that animal and differs in coloration and in the shape of the

incisive foramina In the human mouth, the incisive foramen (also known as: "''anterior palatine foramen''", or "''nasopalatine foramen''") is the opening of the incisive canals on the hard palate immediately behind the incisor teeth. It gives passage to blood vesse ...

, which resembles that seen in '' N. moerex''.Anthony, 1926, p. 5 In his description, Anthony anticipated that ''O. auriventer'' would eventually be demoted to a subspecies of '' Oryzomys albigularis'', which was indeed done in the early 1960s. Subsequently, ''O. auriventer'' was reinstated as a species separate from, though related to, ''O. albigularis'', and ''nimbosus'' was considered to belong to the same species.Musser and Carleton, 2005, p. 1145 When the members of the ''Oryzomys albigularis'' group, including ''O. auriventer'', were transferred to the new genus ''

'' in 2006, ''N. nimbosus'' was recognized as a separate species.

References

Literature cited

*Anthony, H.E. 1926. Preliminary report on Ecuadorean mammals. No. 7. ''American Museum Novitates'' 240:1–6. *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. * {{Taxonbar, from=Q6995003 Mammals of Ecuador Nephelomys Mammals described in 1926