Thomomys clusius

Wyoming Pocket Gopher (Thomomys clusius)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Supramyomorpha
Infraorder:	Castorimorphi
Superfamily:	Geomyoidea
Family:	Geomyidae
Subfamily:	Geomyinae
Tribe:	Thomomyini
Genus:	Thomomys
Binomial details
Thomomys clusius Coues, 1875
Other resources
Full taxonomic details at MDD

Description

From Cudworth and Grenier (2015): "Thomomys clusius is the smallest member of the genus Thomomys (Thaeler and Hinesley 1979). The pelage is pale, yellowish-gray with slight brownish tinge and dull gray at the base of the hairs (Coues 1875). The dorsal pelage is the same color across the cheeks and dorsal part of the head (Thaeler and Hinesley 1979). The margins of the tiny ears are fringed with white hairs, and auricular patches are absent (Coues 1875; Thaeler and Hinesley 1979). The venter, foot, and tail are white, but the snout is blackish (Coues 1875)."

Wyoming Pocket Gopher (Thomomys clusius) photographed by Britt Brito. © Britt Brito.

Wyoming Pocket Gopher (Thomomys clusius) photographed by Nathan Petersen in Carbon County, Wyoming. © Nathan Petersen.

Museum specimens

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  Holotype: USNM 3051/36805. Thomomys clusius. Adult female. Bridger’s Pass, Rocky Mountains, Carbon County, Wyoming. Collected 28 July 1857. Dorsal view.

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  Holotype: USNM 3051/36805. Thomomys clusius. Adult female. Bridger’s Pass, Rocky Mountains, Carbon County, Wyoming. Collected 28 July 1857. Ventral view.

External measurements

Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.

Part of range	Reference	Total length	Tail length	Hindfoot length	Ear length	Mass
Wyoming	Cudworth and Grenier (2015)	161–184 (n=22)	50–70	20–22 (n=22)	5–6

Additional field photos

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  Thomomys clusius photographed by Nathan Petersen in Carbon County, Wyoming. © Nathan Petersen

Skull

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  Holotype: USNM 3051/36805. Thomomys clusius. Adult female. Bridger’s Pass, Rocky Mountains, Carbon County, Wyoming. Collected 28 July 1857. Dorsal view of the skull. The back portion of the skull is damaged.

• 

  Holotype: USNM 3051/36805. Thomomys clusius. Adult female. Bridger’s Pass, Rocky Mountains, Carbon County, Wyoming. Collected 28 July 1857. Ventral view of the skull. The back portion of the skull is damaged.

• 

  Holotype: USNM 3051/36805. Thomomys clusius. Adult female. Bridger’s Pass, Rocky Mountains, Carbon County, Wyoming. Collected 28 July 1857. Dorsal view of the mandible.

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  Holotype: USNM 3051/36805. Thomomys clusius. Adult female. Bridger’s Pass, Rocky Mountains, Carbon County, Wyoming. Collected 28 July 1857. Lateral view of the left mandible. The angular process is damaged and a portion is missing.

Similar species

Key to the species of Thomomys by Verts and Carraway (2005)

Comparison with Thomomys talpoides

From Cudworth and Grenier (2015): "Thomomys clusius can be distinguished from its sympatric congener, T. talpoides (northern pocket gopher), by its small size, lack of dark auricular patches [dark patches of fur behind the ear], and white fringe on the ears, as opposed to the dark fringe on T. talpoides (Thaeler and Hinesley 1979). The presence or absence of an auricular patch may be especially useful in field identification (Keinath et al. 2014).

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  Wyoming Pocket Gopher (Thomomys clusius) photographed by Britt Brito. © Britt Brito.

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  Northern Pocket Gopher (Thomomys talpoides) photographed by ML Watson in Conejos County, Colorado.

Comparison with Thomomys idahoensis

From Cudworth and Grenier (2015): "T. idahoensis (Idaho pocket gopher) has... dark auricular patches similar to those of T. talpoides, and a range that likely lies slightly to the west of T. clusius (Thaeler 1972, 1980; Clark and Stromberg 1987; Patton 2005). The Green River in southwestern Wyoming may represent a range boundary between T. idahoensis and T. clusius (Keinath et al. 2014)."

References

Clark TW, Stromberg MR. 1987. Mammals in Wyoming. University of Kansas, Natural History Publication Education Series 10:1–314.

Coues E. 1875. Synopsis of the Geomyidae. Proceedings of the Academy of Natural Sciences of Philadelphia 27:130–138

Cudworth NL, Grenier MB. 2015. Thomomys clusius (Rodentia: Geomyidae). Mammalian Species 47(923):57-62.

Keinath DA, Griscom HR, Anderson MD. 2014. Habitat and distribution of the Wyoming pocket gopher (Thomomys clusius). Journal of Mammalogy 95:803–813.

Patton JL. 2005. Family Geomyidae. Pp. 859–870 in Mammal species of the world: a taxonomic and geographic reference. 3rd ed. (DE Wilson and DM Reeder, eds.). Johns Hopkins University Press, Baltimore, Maryland.

Thaeler Jr CS. 1972. Taxonomic status of the pocket gophers, Thomomys idahoensis and Thomomys pygmaeus (Rodentia, Geomyidae). Journal of Mammalogy 53:417–428.

Thaeler Jr CS. 1980. Chromosome numbers and systematic relations in the genus Thomomys (Rodentia: Geomyidae). Journal of Mammalogy 61:414–422.

Thaeler Jr. CS, Hinesley LL. 1979. Thomomys clusius, a rediscovered species of pocket gopher. Journal of Mammalogy 60:480–488.