''Scolomys'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 tribe

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 S ...

of the 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 ...

. Some evidence suggests that it is related to ''

Zygodontomys ''Zygodontomys'' is a genus of rodent in the tribe Oryzomyini of the family Cricetidae. Its closest relative may be '' Scolomys''. It ranges from Central America Central America ( es, América Central or ) is a subregion of the Americas ...

''. It is characterized, among other traits, by spiny fur. It contains two species, '' S. melanops'' and '' S. ucayalensis''.

Taxonomy

The genus ''Scolomys'' was first described by the American zoologist H. E. Anthony in 1920, to accommodate six specimens collected by the British-born American zoologist

George Henry Hamilton Tate George Henry Hamilton Tate (April 30, 1894 – December 24, 1953) was a British-born United States, American zoologist and botanist, who worked as a mammalogist for the American Museum of Natural History in New York City. In his lifetime he wro ...

on the eastern slopes of the Andes in Ecuador. These specimens belonged to a single species ''

Scolomys melanops ''Scolomys melanops'', also known as the short-nosed scolomys, South American spiny mouse, Ecuadorian spiny mouse, or gray spiny mouse, is a species of rodent in the genus ''Scolomys'' of family Cricetidae. It is a forest mouse and was thought to ...

'', and for a long time the genus was considered to be

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

. However, following survey work in the upper

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...

many decades later, a further species '' S. ucayalensis'' was described from northern Peru by Pacheco in 1991, followed by a third, ''S. juruaense'' from western Brazil by Patton and da Silva in 1994. In 2004, Gomez-Laverde and co-workers reviewed the systematics of the genus and its distribution, and suggested that ''S. juruaense'' was not sufficiently distinct from ''S. ucayalensis'' to warrant being classified as a separate species.

Characteristics

Members of this genus are small rodents with a head-and-body length of and a tail of . They have small, broad heads, with small rounded, nearly-naked ears, and short, dense, spiny fur. The upper parts are grizzled reddish-brown to black while the underparts are greyish. The dorsal pelage is a mixture of slender hairs with reddish or blackish tips, and stouter, flattened spines gradually darkening towards the end. The fore feet have five pads on the sole. The hind feet are broad and short, with hairy heels and naked soles, with five or six pads. The upper surface of the hind feet has long silvery hairs sprouting beside the nail bases but not hiding the nails. The tail is scantily-haired and has no terminal tuft of hair. The female has three pairs of

mammae A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primat ...

which feature distinguishes this genus from other members of the ''Oryzomyini'' tribe which have four pairs.

References

* *Weksler, M. 2006
Phylogenetic 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. {{Taxonbar, from=Q469277 Rodent genera Taxonomy articles created by Polbot