A cotton rat is any member of the

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 ...

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 ...

''Sigmodon''. Their name derives from their damaging effects on cotton as well as other plantation crops, such as sugarcane, corn, peanut and rice. Cotton rats have small ears and dark coats, and are found in

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and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. Members of this genus are

distributed Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

in the

Southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, Ne ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

, and South American countries of:

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

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 ...

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

Guyana Guyana ( or ), officially the Cooperative Republic of Guyana, is a country on the northern mainland of South America. Guyana is an indigenous word which means "Land of Many Waters". The capital city is Georgetown. Guyana is bordered by the ...

, and

Suriname Suriname (; srn, Sranankondre or ), officially the Republic of Suriname ( nl, Republiek Suriname , srn, Ripolik fu Sranan), is a country on the northeastern Atlantic coast of South America. It is bordered by the Atlantic Ocean to the north ...

. Many of the species are found in Mexico. They are primarily herbivores. The molars of cotton rats are S-shaped when viewed from above. The genus name literally means S-tooth. ''

Sigmodon hispidus The hispid cotton rat (''Sigmodon hispidus'') is a rodent species long thought to occur in parts of South America, Central America, and southern North America. However, recent taxonomic revisions, based on mitochondrial DNA sequence data, have ...

'' was the first

model organism A model organism (often shortened to model) is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workin ...

to be used in

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research.

Classification

*Genus ''Sigmodon'' **Subgenus ''Sigmodon'' ***''Sigmodon hispidus'' species group ****'' Sigmodon alleni'' - Allen's cotton rat ****'' Sigmodon arizonae'' - Arizona cotton rat ****'' Sigmodon hirsutus'' - Southern cotton rat ****''

'' - Hispid cotton rat ****'' Sigmodon mascotensis'' - Jaliscan cotton rat ****'' Sigmodon ochrognathus'' - Yellow-nosed cotton rat ****'' Sigmodon planifrons'' - Miahuatlán cotton rat ****'' Sigmodon toltecus'' - Toltec cotton rat ****'' Sigmodon zanjonensis'' - montane cotton rat ***''Sigmodon fulviventer'' species group ****'' Sigmodon fulviventer'' - tawny-bellied cotton rat ****'' Sigmodon inopinatus'' - unexpected cotton rat ****'' Sigmodon leucotis'' - white-eared cotton rat ****'' Sigmodon peruanus'' - Peruvian cotton rat **Subgenus ''Sigmomys'' ***'' Sigmodon alstoni'' - Alston's cotton rat

References

External links

Tree of Life: cotton rats
Sigmodontinae Rat, Cotton Taxa named by George Ord {{Sigmodon-stub