The

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Sciurus'' ( or ) contains most of the common, bushy-tailed

squirrel Squirrels are members of the family Sciuridae (), a family that includes small or medium-sized rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrel ...

s in

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and

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Species

The number of species in the genus is subject to change. In 2005, Thorington & Hoffman- whose taxonomic interpretation is followed by the IUCN website- accepted 28 species in the genus: Genus ''Sciurus'' Sciurus granatensis Humboldt 1811

*Subgenus ''Sciurus'' ** Allen's squirrel, ''Sciurus alleni'' **

Arizona gray squirrel The Arizona gray squirrel (''Sciurus arizonensis'') is a tree squirrel, in the genus ''Sciurus'', endemic to the canyons and valleys surrounded by deciduous and mixed forests in eastern Arizona and northern Mexico. It is threatened by habitat l ...

, ''Sciurus arizonensis'' **

Mexican gray squirrel The Mexican gray squirrel (''Sciurus aureogaster'', F. Cuvier), also known as the red-bellied squirrel, goes by the name or in Mexico. The species consists of two subspecies ''S.'' ''aureogaster'' and ''S. nigrescens'', which are native to Me ...

, ''Sciurus aureogaster'' ** Eastern gray squirrel, ''Sciurus carolinensis'' ** Collie's squirrel, ''Sciurus colliaei'' ** Deppe's squirrel, ''Sciurus deppei'' ** Japanese squirrel, ''Sciurus lis'' **

Calabrian black squirrel The Calabrian black squirrel (''Sciurus meridionalis'') is a species of tree squirrel in the genus ''Sciurus'', endemic to the forests of the regions of Calabria and Basilicata, in the south of the Italian Peninsula. Taxonomy It has long been c ...

, ''Sciurus meridionalis'' ** Mexican fox squirrel, ''Sciurus nayaritensis'' **

Fox squirrel The fox squirrel (''Sciurus niger''), also known as the eastern fox squirrel or Bryant's fox squirrel, is the largest species of tree squirrel native to North America. It is sometimes mistaken for the American red squirrel or eastern gray squirr ...

, ''Sciurus niger'' ** Peters's squirrel, ''Sciurus oculatus'' **

Variegated squirrel The variegated squirrel (''Sciurus variegatoides'') is a tree squirrel in the genus ''Sciurus'' found in Costa Rica, El Salvador, Guatemala, Honduras, southern Mexico, Nicaragua, and Panama. Fifteen subspecies are recognised. It is a common squir ...

, ''Sciurus variegatoides'' ** Eurasian red squirrel, ''Sciurus vulgaris'' ** Yucatan squirrel, ''Sciurus yucatanensis'' *Subgenus ''Otosciurus'' ** Abert's squirrel, ''Sciurus aberti'' *Subgenus ''Guerlinguetus'' ** Brazilian squirrel (Guianan squirrel), ''Sciurus aestuans'' ** Yellow-throated squirrel, ''Sciurus gilvigularis'' ** Red-tailed squirrel, ''Sciurus granatensis'' ** Bolivian squirrel, ''Sciurus ignitus'' ** Ingram's squirrel, ''Sciurus ingrami'' ** Andean squirrel, ''Sciurus pucheranii'' ** Richmond's squirrel, ''Sciurus richmondi'' ** Sanborn's squirrel, ''Sciurus sanborni'' ** Guayaquil squirrel, ''Sciurus stramineus'' *Subgenus ''Tenes'' **

Persian squirrel The Caucasian squirrel (''Sciurus anomalus'') or Persian squirrel, is a tree squirrel in the genus ''Sciurus'' found in temperate broadleaf and mixed forests in south-western Asia. The species is traditionally said to have first been described i ...

, ''Sciurus anomalus'' *Subgenus ''Hadrosciurus'' ** Fiery squirrel, ''Sciurus flammifer'' ** Junín red squirrel, ''Sciurus pyrrhinus'' *Subgenus ''Hesperosciurus'' **

Western gray squirrel The western gray squirrel (''Sciurus griseus'') is a tree squirrel found along the western coast of the United States and Mexico. In some places, this species has also been known as the silver-gray squirrel, the California gray squirrel, the Ore ...

, ''Sciurus griseus'' *Subgenus ''Urosciurus'' ** Northern Amazon red squirrel, ''Sciurus igniventris'' ** Southern Amazon red squirrel, ''Sciurus spadiceus'' In 2015, 15–17 species were left in the genus ''Sciurus'' after de Vivo & Carmignotto comprehensively reviewed South American Sciuridae for the first time in many decades and proposed numerous changes; synonymising some species and many subspecies, splitting another species, and naming new species. They followed

Joel Asaph Allen Joel Asaph Allen (July 19, 1838 – August 29, 1921) was an American zoology, zoologist, mammalogy, mammalogist, and ornithology, ornithologist. He became the first president of the American Ornithologists' Union, the first curator of birds and ma ...

's unsatisfying 1914 attempt in splitting the genus ''Sciurus'' by raising the South American subgenera to the rank of genus, adding ''Urosciurus'' to ''Hadrosciurus'', and splitting the genus ''Guerlinguetus'' in three. Their taxonomic treatment might also require ''Sciurus deppei'' to be moved to ''Notosciurus''. A 2020 paper published on the taxonomy of

Sciurinae Sciurinae () is a subfamily of squirrels (in the family Sciuridae), uniting the flying squirrels with certain related tree squirrels. Older sources place the flying squirrels in a separate subfamily (Pteromyinae) and unite all remaining sciurids i ...

split ''Sciurus'' into multiple new genera and elevated several subgenera. The paper included genetic sampling from almost all recognized species and recommends the following species assignments: *''Sciurus'' **

, ''S. anomalus'' ** Eurasian red squirrel, ''S. vulgaris'' ** Japanese squirrel, ''S. lis'' *''Hesperosciurus'' ** Abert's squirrel, ''H. aberti'' **

, ''H. griseus'' *''Parasciurus'' ** Allen's squirrel, ''P. alleni'' **

, ''P. arizonensis'' ** Mexican fox squirrel, ''P. nayaritensis'' **

, ''P. niger'' ** Peters's squirrel, ''P. oculatus'' *''Neosciurus'' ** Eastern gray squirrel, ''N. carolinensis'' *''Echinosciurus'' **

, ''E. aureogaster'' ** Collie's squirrel, ''E. colliaei'' ** Deppe's squirrel, ''E. deppei'' **

, ''E. variegatoides'' ** Yucatan squirrel, ''E. yucatanensis'' *''Simosciurus'' **'' S. nebouxii'' ** Guayaquil squirrel, ''S. stramineus'' *''Guerlinguetus'' ** Brazilian squirrel, ''G. aestuans'' **'' G. brasiliensis'' *''Hadrosciurus'' ** Bolivian squirrel, ''H. ignitus'' ** Northern Amazon red squirrel, ''H. igniventris'' ** Junín red squirrel, ''H. pyrrhinus'' ** Southern Amazon red squirrel, ''H. spadiceus'' Additionally, the paper suggests moving Andean squirrel back to subtribe Microsciurina, the dwarf squirrels, and assigns it to the newly described genus ''Leptosciurus''. The paper's findings agree with prior assessments to synonymize Richmond's squirrel into Red-tailed squirrel and reassigns the Red-tailed squirrel into the previously

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 "unisp ...

Asian genus ''

Syntheosciurus Bangs's mountain squirrel (''Syntheosciurus brochus'') is a poorly known species of tree squirrel, that only lives in Costa Rica and Panama. It can be found in mountain rain forests at an altitude between , and lives mainly in the tree tops, but ...

'', also in Microsciurina. The paper did not include genetic sampling or taxonomic suggestions for ''gilvigularis'', ''meridionalis'', ''sanborni'', or ''flammifer''.

References

* *Nowak, Ronald M. 1999. ''Walker's Mammals of the World'', 6th edition. Johns Hopkins University Press, 1936 pp. *Eisenberg, J.F. 1989.
Mammals of the Neotropics, Volume 1: The Northern Neotropics: Panama, Colombia, Venezuela, Guyana, Suriname, French Guiana
.

University of Chicago Press The University of Chicago Press is the university press of the University of Chicago, a Private university, private research university in Chicago, Illinois. It is the largest and one of the oldest university presses in the United States. It pu ...

. *Redford, K.H. and Eisenberg, J.F. 1992.
Mammals of the Neotropics, Volume 2: The Southern Cone: Chile, Argentina, Uruguay, Paraguay
. University of Chicago Press. *Eisenberg, J.F. and Redford, K.H. 1999.
Mammals of the Neotropics, Volume 3: The Central Neotropics: Ecuador, Peru, Bolivia, Brazil
. University of Chicago Press.

Footnotes

Rodent genera Extant Miocene first appearances Taxa named by Carl Linnaeus {{Squirrel-stub