Oriental Basin pocket gopher

The Oriental Basin pocket gopher ("Cratogeomys fulvescens") is a species of pocket gopher which is endemic to Mexico. It was first described in 1895 by Clinton Hart Merriam. It was considered to be a subspecies of Merriam's pocket gopher ("Cratogeomys merriami") in the late 20th and early 21st century but has been reinstated as its own species. The IUCN Red List has evaluated it to be of least concern.
Description.
"C. fulvescens" is mid-sized for the genus "Cratogeomys" and exhibits sexual dimorphism in size. Adult males weigh of and adult females weigh . Its fur coloration is "grizzled yellowish-brown" with "a strong mixture of black-tipped hairs"; the underside is paler than the dorsal fur. The cranial width of its skull is typically less than , making it small for the genus. The dental formula is . Each upper incisor has a longitudinal groove along its anterior surface. The total body length is .
Distribution.
This species is endemic to a small region in the southern half of Mexico. Its range is in the Oriental Basin of the Trans-Mexican Volcanic Belt, and is within the Mexican states of Puebla, Tlaxcala, and Veracruz. The elevation in its distribution spans . Merriam noted the type locality as: "Chalchicomula, State of Puebla, Mexico"; this city is now known as Ciudad Serdán. The type locality for the formerly-recognized subspecies "C. f. subluteus" is Perote, Veracruz.
Taxonomic history.
The American zoologist Clinton Hart Merriam wrote the species description for "C. fulvescens" in 1895. Merriam based his description on eleven specimens from Puebla and Veracruz, Mexico. In Merriam's classification of "Cratogeomys", "C. fulvescens" was grouped with "C. castanops" on the basis of cranial morphology.
In 1968, Robert J. Russell reclassified "Cratogeomys" to be a subgenus of "Pappogeomys". Russell also analyzed Merriam's "C. fulvescens" as being a subspecies of what was in his work called "Pappogeomys Cratogeomys merriami". Russell stated that of the seven subspecies he recognized for "P." ("C.") "merriami", "the most divergent" was "P." ("C.") "m. fulvescens" due to differences in coloration, size, and cranial morphology. This classification in E. Raymond Hall's 1981 "The Mammals of North America" also used the combination "P." ("C.") "m. fulvescens" for this taxon. "Cratogeomys" was reinstated as a genus in 1982; the third edition of "Mammal Species of the World" refers to this taxon as "C. m. fulvescens".
"C. fulvescens" was reinstated as its own species in 2005 due to a genetic and morphological study by Mark S. Hafner and colleagues. They placed it in the "C. castanops" species group.
No subspecies are presently recognized. A subspecies, "C. f. subluteus" had been described in 1934 by Edward William Nelson and Edward Alphonso Goldman. This subspecies was also known by the common names "yellow pocket gopher" and "fulvous pocket gopher".
The holotypes for "C. fulvescens" and for "C. f. subluteus" are both in the collections of the U.S. National Museum of Natural History, Washington, DC. Each specimen consists of its preserved skin and its skull. Nelson and Goldman collected both holotypes: The "C. fulvescens" holotype was collected in 1894, and the "C. f. subluteus" holotype was collected in 1893.
The specific epithet (, "yellowing") is the Latin present participle of the inchoative form of the verb meaning "to become tawny". The epithet of its formerly recognized subspecies, (), is a Latin adjective meaning "yellowish". The common name for the species, Oriental Basin pocket gopher, refers to the Oriental Basin in Mexico, where it is found. Its common name in Spanish is .
Biology.
"C. fulvescens"'s diet consists of rhizomes, bulbs, and roots. Pregnancy has been observed from December through February. Because pregnancy was not observed in July, it is thought they only have one litter each year.
Two species of chewing lice in the genus "Geomydoecus" have "C. fulvescens" as a host: "G. fulvescens" and "G. veracruzensis". Both species were described in 1971 by Roger D. Price and K. C. Emerson. The flea species "Dasypsyllus megasoma" and "Meringis altipecten" were also observed on "C. fulvescens"; although it is thought the presence of "M. altipecten" is thought to have been accidental rather than due to being a typical ectoparasite for the species. The nematode species "Vexillata convoluta" is also a parasite of "C. fulvescens".
Genetics.
Its diploid number is 2n=40 and its fundamental number is FN=72. "C. fulvescens" contains an autapomorphic allele for the gene RAG1 distinguishing it from "C. perotensis" and "C. merriami".
Conservation status and relationship with humans.
The IUCN Red List has classified this species as a least-concern species, and SEMARNAT did not include it in its 2010 list of threatened or endangered mammals of Mexico. Although its observed habitat is less than , it is believed to be "common and adaptable". Part of its range is affected by habitat loss due to human expansion. "C. fulvescens" were found as roadkill along a highway going through its range. Mark S. Hafner wrote there ought to be further studies on its conservation status, particularly as its geographic range is smaller than that of other Mexican pocket gophers. "C. fulvescens" have been observed in farmland and might be considered to be a pest as they destroy crops including wheat, corn, and beans.