Geomys texensis

Llano Pocket Gopher
(*Geomys texensis*)
Llano Pocket Gopher (Geomys texensis)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Supramyomorpha
Infraorder:	Castorimorphi
Superfamily:	Geomyoidea
Family:	Geomyidae
Subfamily:	Geomyinae
Tribe:	Geomyini
Genus:	Geomys
Subgenus:	Geomys (subgenus)
Binomial details
	Geomys texensis C. H. Merriam, 1895
Other resources
	Full taxonomic details at MDD

The Llano Pocket Gopher (Geomys texensis) pocket gopher found in the grasslands and open woodlands of central Texas. Friable soils are important as this species is fossorial and rarely leaves its network of underground burrows. It can be very difficult to distinguish from other pocket gophers. Individuals found above ground are often dispersing juveniles.

Description

From Cramer and Cameron (2001): "Adult G. texensis have a liver-brown dorsum mixed with black-tipped hairs, a white venter, and white feet (Merriam 1895), whereas subadults have a tawny brown pelage (Cameron 1999). Winter pelage is darker overall and hairs on venter are plumbeous at base, but are white throughout in summer (Merriam 1895). Additionally, throat has a fulvous buffy collar that can be interrupted along midline (Merriam 1895). Juveniles have black-tipped hairs concentrated along midline of dorsum, but this color is not found in adults (Merriam 1895).

Museum specimens

Holotype: USNM 97086. Geomys texensis llanensis. Adult male. Llano, Llano County, Texas. Collected 15 May 1899.
Holotype: USNM 97086. Geomys texensis llanensis. Adult male. Llano, Llano County, Texas. Collected 15 May 1899.

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
Texas (Mason and Llano Cos.)	Davis (1938)	females: 213–230 (n=8); males: 243–272 (n=7)	females: 58–70 (n=8); males: 63–80 (n=7)	females: 29–30 (n=8); males: 63–80 (n=7)

Skull

Holotype: USNM 97086. Geomys texensis llanensis. Adult male. Llano, Llano County, Texas. Collected 15 May 1899. Dorsal view of the skull.
Holotype: USNM 97086. Geomys texensis llanensis. Adult male. Llano, Llano County, Texas. Collected 15 May 1899. Ventral view of the skull.
Holotype: USNM 97086. Geomys texensis llanensis. Adult male. Llano, Llano County, Texas. Collected 15 May 1899. Lateral view of the skull.
Holotype: USNM 97086. Geomys texensis llanensis. Adult male. Llano, Llano County, Texas. Collected 15 May 1899. Dorsal view of the mandible.
Holotype: USNM 97086. Geomys texensis llanensis. Adult male. Llano, Llano County, Texas. Collected 15 May 1899. Lateral view of the left mandible.

Similar species

Comparison with Geomys bursarius

From Schmidly and Bradley (2016): "Morphologically, the Llano pocket gopher is slightly smaller than the plains pocket gopher, but molecular data are required to reliably distinguish the two species."

References

Bradley RD, Pham AT, Rich KA, Roberts EK, Soniat TJ, Poehlein CM, Mills MN, Ballard M, Pitts RM, Lindsey LL, Halsey MK. 2023. Genetic identification of pocket gophers (Genera Cratogeomys, Geomys, and Thomomys) in Texas and surrounding areas. Museum of Texas Tech University.

Cameron GN. 1999. Llano pocket gopher (Geomys texensis). Pp. 490-491 in The Smithsonian book of North American mammals (D. E. Wilson and S. Ruff, eds.). Smithsonian Institution Press, Washington, D.C.

Cramer MJ, Cameron GN. 2001. Geomys texensis. Mammalian Species 679:1–3. http://www.jstor.org/stable/3504428

Davis WB. 1938. Critical notes on pocket gophers from Texas. Journal of Mammalogy 19(4):488-490.

Merriam CH. 1895-01-31. Revision of the pocket gophers, family Geomyidae, exclusive of the species of Thomomys. North American Fauna 8:1-262.

Schmidly DJ, Bradley RD. 2016. The mammals of Texas. Austin (TX, USA): University of Texas Press.