Geographic Variation in the Pocket Gopher, Cratogeomys castanops, in Coahuila, México

by Robert J. Russell; Rollin H. Baker

Cratogeomys castanops subsimus occurs in scattered colonies in sandy soils principally in the upper drainage of the Río Salinas. Specimens have also been taken from the foothills of the Sierra Madre Oriental and westward on the elevated desert plains.

Specimens examined.--Total, 22, from: 3 mi. S and 3 mi. E Muralla, 3800 ft., 3; 2 mi. N Santa Cruz, 2; 21 mi. S and 11 mi. E Australia, 4400 ft., 6; Jaral, 3860 ft., 4 (BSC); Hacienda El Tulillo, 5 km. S Hipolito, 2; 17 mi. N and 8 mi. W Saltillo, 5200 ft., 1; 3 mi. N and 5 mi. W La Rosa, 3600 ft., 1; 12 mi. N and 10 mi. E Parras, 5000 ft., 1; N foot Sierra Guadalupe, 9 mi. S and 5 mi. W General Cepeda, 6200 ft., 1; N foot Sierra Guadalupe, 10 mi. S and 5 mi. W General Cepeda, 6500 ft., 1.

Cratogeomys castanops goldmani Merriam

1895.

Cratogeomys castanops goldmani Merriam, N. Amer. Fauna 8:160, January 31, type from Cañitas, Zacatecas.

Distribution.--Plains of northeastern Zacatecas, northward into extreme southwestern Coahuila (see [fig. 1]).

Comparisons.--Compared with Cratogeomys castanops subnubilus, found to the east, goldmani differs in: Body larger, tail and hind foot longer; color paler, more rufous and less blackish; skull larger; zygomata more widely flaring; palate larger; rostrum broader; nasals longer; maxillary teeth larger. Compared with Cratogeomys castanops rubellus Nelson and Goldman, found to the southeast, goldmani differs in: Body and skull smaller; zygomata less widely flaring; palate shorter; rostrum narrower; maxillary teeth smaller.

Remarks.--Records of goldmani given here extend the known range of this subspecies northward into southwestern Coahuila. Specimens assigned to this subspecies from Coahuila compare favorably with topotypes of goldmani (see [tables 1 and 2]) but are slightly paler, and in this respect show some relationship to excelsus. The ranges of these two subspecies however, are partly isolated by mountainous country in southern Coahuila.

Specimens examined.--Total, 6, from: W foot Pico de Jimulco, 4600 ft., 1; Valley Río [Aguanaval], 1 mi. S Jimulco, 4; 1-1/2 mi. N Parras, 1.

Cratogeomys castanops subnubilus Nelson and Goldman

1934.

Cratogeomys castanops subnubilus Nelson and Goldman, Proc. Biol. Soc. Washington, 47:145, June 13, type from Carneros, 6800 ft., Coahuila.