Megascapheus

Genus *Megascapheus*
Genus Megascapheus
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Supramyomorpha
Infraorder:	Castorimorphi
Superfamily:	Geomyoidea
Family:	Geomyidae
Subfamily:	Geomyinae
Tribe:	Thomomyini

Pocket gophers are burrowing rodents in the family Geomyidae. They are cryptic species and can be very difficult to distinguish based on external morphological characters alone. Members in the genus Megascapheus are referred to as the smooth-toothed tooth-digging pocket gophers. Their upper incisors are smooth (lack grooves), which distinguishes them from the Yellow-faced Pocket Gopher (Cratogeomys castanops) and pocket gophers in the genus Geomys. Morphological differences between Megascapheus and Thomomys (another group of smooth-toothed gophers) is best explained by Álvarez-Castañeda and Segura-Trujillo (2025): "Morphological difference between Megascapheus in relation to Thomomys are: the upper incisors procumbent and their root between the fourth upper premolars and the first upper molars vs upper incisors not procumbent and their root above the fourth upper premolars; sphenoidal fissure open vs closed (except for some specimens of T. clusius); angular process continuous, with a well-developed flange along the ventral ramus side vs not continuous, with a weakly developed flange along the ventral ramus side; rostrum heavy vs rostrum slender; base of the first lower premolars inclined anteriorly vs nearly perpendicular to the occlusal surface of the toothrow; infraorbital canal openings anterior to the incisive foramina vs directly above or slightly posterior to the incisive foramina; anterior enamel plate of the first lower premolars not recurved vs recurved, frequently forming a shallow re-entrant angle; anterior enamel plate of the first lower premolars narrow and broadly separated from the lateral enamel plate on the lingual side, vs only slightly separated from the posterior enamel plate (rarely continuous), with the lateral enamel plate on the lingual side; chromosome number of living forms from 74 to 82 vs from 40 to 60 (Nelson and Goldman 1934; Russell 1968; Álvarez-Castañeda 2024)."

Species in the United States

Southwestern Texas Pocket Gopher (Megascapheus baileyi) photographed by Mickey Dylan in Jeff Davis County, Texas. Pelage color ranges from buffy-yellow to pinkish-buff to cinnamon to dark gray. Incisors are smooth and lack grooves.
Dorsal view of a Botta's Pocket Gopher (Megascapheus bottae) collected in 1894 in Merced County, California. Incisors are smooth and lack grooves.
Camas Pocket Gopher (Megascapheus bulbivorus) photographed by Luis Cuellar Robles in Portland, Oregon. The dorsum is sooty brown and the ears and nose blackish; the venter is lead colored except for an irregular-shaped white patch on the throat. Incisors are smooth and lack grooves.
New Mexico Pocket Gopher (Megascapheus connectens) collected in 1935 in Bernalillo County, New Mexico. Fresh summer pelage is cinnamon buff; whitish below with plumbeous areas and with cinnamon buff extending onto the pectoral region. Winter pelage with a reduced amount of cinnamon buff on the upper parts producing a "gray" coat." Incisors are smooth and lack grooves.
Fulvous Pocket Gopher (Megascapheus fulvus) photographed by dumplingbug around Tucson, Arizona. Incisors are smooth and lack grooves.
Dorsal view of a Northern California Pocket Gopher (Megascapheus laticeps) collected in 1905 in Mendocino County, California. Incisors are smooth and lack grooves.
Dorsal view of a Southern California Pocket Gopher (Megascapheus nigricans) collected in 1893 in Riverside County, California. Incisors are smooth and lack grooves.
Ruidoso Pocket Gopher (Megascapheus ruidosae) collected in 1931 in Lincoln County, New Mexico. Color is fuscous to fuscous-black above with underparts having a strong wash of ochraceous-tawny; its tail is black except for the distal third which is white; its feet and ankles are white. Incisors are smooth and lack grooves.
Dorsal view of a Townsend's Pocket Gopher (Megascapheus townsendii) collected in 1913 Canyon County, Idaho. Incisors are smooth and lack grooves.
Dorsal view of a Southern Pocket Gopher (Megascapheus umbrinus) collected in 1908 in Hidalgo County, New Mexico. Incisors are smooth and lack grooves.

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).

Available taxon pages

The following subgenera are available on WhiskerWiki for this genus:

Subgenus: No information

Range maps for species in the United States

Southwestern Texas Pocket Gopher (Megascapheus baileyi). Elevated to specific status by Bradley et al. (2023).
Botta's Pocket Gopher (Megascapheus bottae). Warning! The ranges above may be unreliable. Recent molecular analyses have led to significant changes in our understanding of the distribution of this species. The most recent published range 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 bottae as rest of California, north and west of the Colorado River." Based on Figure 2. in Álvarez-Castañeda (2010), the range of bottae should include southern Oregon, southern Idaho, California, Nevada, Utah, Colorado, northern Arizona, and northern New Mexico. The range discrepancy between Álvarez-Castañeda (2010) and Álvarez-Castañeda (2024) is substantial.
Camas Pocket Gopher (Megascapheus bulbivorus)
New Mexico Pocket Gopher (Megascapheus connectens). Elevated to specific status by Bradley et al. (2023). Distribution (dark green) of connectens is based on Sands and Finley (1959). Distribution (light green) of connectens is based on Bradley et al. (2023). Bradley et al. (2023) note that their distribution is approximated.
Fulvous Pocket Gopher (Megascapheus fulvus) Elevated to specific status by Bradley et al. (2023). Warning! The ranges above may be unreliable. 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.
Northern California Pocket Gopher (Megascapheus laticeps)
Southern California Pocket Gopher (Megascapheus nigricans)
Ruidoso Pocket Gopher (Megascapheus ruidosae). Elevated to specific status by Bradley et al. (2023). The dark green area represents the distribution of Megascapheus ruidosae according to Bradley et al. (2023). The light green area represents the range of Megascapheus baileyi subspecies actuosus and an area of uncertainty for Megascapheus ruidosae. Accordingly to Bradley et al. (2023), some individuals of actuosus from the type locality in Corona, NM, possessed a mtDNA haplotype reflective of actuosus, whereas others possessed a haplotype associated with ruidosae: "Further studies are needed to determine whether samples of actuosus that presumably hybridize with ruidosae should be assigned to this new species".
Townsend's Pocket Gopher (Megascapheus townsendii)
Southern Pocket Gopher (Megascapheus umbrinus)

References

Álvarez-Castañeda ST. 2010. Phylogenetic structure of the Thomomys bottae–umbrinus complex in North America. Molecular Phylogenetics and evolution 54(3): 671-679.

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