Megascapheus fulvus

Fulvous Pocket Gopher
(*Megascapheus fulvus*)
Fulvous Pocket Gopher (Megascapheus fulvus)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Supramyomorpha
Infraorder:	Castorimorphi
Superfamily:	Geomyoidea
Family:	Geomyidae
Subfamily:	Geomyinae
Tribe:	Thomomyini
Genus:	Megascapheus
Binomial details
	Megascapheus fulvus (S. W. Woodhouse, 1853)
Other resources
	Full taxonomic details at MDD

Warning! The American Society of Mammalogists' Mammal Diversity Database states: "further research using more integrative taxonomic methods is needed to confirm this taxonomic arrangement." In essence, the statement emphasizes that while the existing taxonomic arrangement might be a starting point, a more thorough investigation using integrative taxonomy is needed to confirm or refine species boundaries and provide stronger evidence for species status.

Recent molecular analyses have led to significant changes in our understanding of the distribution of this species. The most recent published range (light green) of this species was by Álvarez-Castañeda (2024) in Mammals of North America-Volume 2: Systematics and Taxonomy; however, this is not a peer reviewed publication. That range map is based on earlier, peer-reviewed molecular analyses by Álvarez-Castañeda (2010), which lists the range of fulvus as "south and east of the Colorado River to the Sierra Madre Occidental in Sonora." The range presented in dark green is based on Álvarez-Castañeda (2010) and Bradley et al. (2023). The range discrepancy between Álvarez-Castañeda (2010) and Álvarez-Castañeda (2024) is substantial.

Description

Museum specimens

Holotype: USNM 214611. Adult male. Camp Verde, Yavapai County, Arizona. Collected 25 July 1916.
Holotype: USNM 214611. Adult male. Camp Verde, Yavapai County, Arizona. Collected 25 July 1916.

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
Holotype USNM 214611 (Camp Verde, Yavapai Co., AZ)	Smithsonian National Museum of Natural History	236	71	31

Skull

Holotype: USNM 214611. Adult male. Camp Verde, Yavapai County, Arizona. Collected 25 July 1916. Dorsal view of the skull.
Holotype: USNM 214611. Adult male. Camp Verde, Yavapai County, Arizona. Collected 25 July 1916. Ventral view of the skull.
Holotype: USNM 214611. Adult male. Camp Verde, Yavapai County, Arizona. Collected 25 July 1916. Lateral view of the skull.
Holotype: USNM 214611. Adult male. Camp Verde, Yavapai County, Arizona. Collected 25 July 1916. Dorsal view of the mandible.
Holotype: USNM 214611. Adult male. Camp Verde, Yavapai County, Arizona. Collected 25 July 1916. Lateral view of the left mandible.

Taxonomic notes

Elevation of subgenera within genus Thomomys Wied-Neuwied, 1839

Genetic analyses (CytB and COI) by Álvarez-Castañeda and Segura-Trujillo (2025) found that the two subgenera within the genus Thomomys Wied-Neuwied, 1839 — Megascapheus and Thomomys — are genetically distinct. Morphological and genetic data support considering these differences sufficient at the genus level. Both subgenera Megascapheus and Thomomys were elevated to the taxonomic rank of genus by Álvarez-Castañeda and Segura-Trujillo (2025).

Similar species

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References

Álvarez-Castañeda ST. 2024. Mammals of North America-Systematics and Taxonomy. Volume 2. Springer.

Álvarez-Castañeda ST. 2010. Phylogenetic structure of the Thomomys bottae–umbrinus complex in North America. Molecular Phylogenetics and evolution 54(3): 671-679. https://doi.org/10.1016/j.ympev.2009.11.012

Álvarez-Castañeda ST, Segura-Trujillo CA. 2025. Genus-level review of pocket gophers in the family Geomyidae. Therya 16(1): 41-75.

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. https://www.depts.ttu.edu/nsrl/publications/downloads/SP78.pdf

Woodhouse SW. 1853-02-07. Description of a new species of pouched rat of the genus Geomys, Raf. Proceedings of the Academy of Natural Sciences of Philadelphia 6(6):201-202.