Subspeciation in the Kangaroo Rat, Dipodomys ordii / KU. Vol 1 No 23

by Henry W. Setzer

Wyoming: Fremont County: 2-1/2 mi. W Shoshoni, 80 (KU); Granite Mountain, 1 (UM). Natrona County: 1 mi. NE Casper, 19 (KU); Casper, 7 (USBS); Sun, 8 (USBS). Converse County: Douglas, 2 (USBS). Niobrara County: Van Tassel Creek, 1 (CM). Carbon County: Fort Steele, 1 (USBS). Goshen County: Rawhide Butte, 1 (USBS).

Nebraska: Sioux County: Warbonnet Canyon, 6 (MHS); Glen, 1 (MHS); Agate, 3 (1 UM; 2 CNHM); Jim Creek, 1 (MHS). Box Butte County: 16 mi. NE Alliance, 4 (UM). Sheridan County: 12 mi. S Gordon, 3 (MVZ); 5 mi. N Antioch, 4 (UM); 4 mi. N Antioch, 3 (UM). Cherry County: Valentine, 9 (6 USBS; 2 USNM; 1 NU); 15 mi. E Gordon, 1 (CNHM); Niobrara River, 3 (USBS); 18 mi. NW Kennedy, 3 (2 USBS; 1 MHS); Valentine Lake Refuge, 1 (NU); Kennedy, 10 (3 MVZ; 5 USBS; 2 USNM); 30 mi. S Wood Lake, 4 (CNHM); Cherry, 7 (NU); near Clark's Canyon, 7 (USBS). Rock County: Perch, 12 (10 AMNH; 2 CNHM). Antelope County: Neligh, 8 (1 USBS; 7 MHS). Scotts Bluff County: Mitchell, 1 (MHS). Hooker County: Kelso, 5 (UM). Thomas County: Halsey, 1 (MHS); Dismal River, 2 (USBS). Custer County: 1 mi. NW Gavin, 6 (2 MVZ; 4 UM); Gavin, 3 (UM); 8 mi. NW Anselmo, 1 (UM); 7 mi. NW Anselmo, 1 (UM). Lincoln County: Birdwood Creek, 2 (USBS); Brady, 4 (NU); Hackberry Lake, 13 (UM).

Colorado: Larimer County: Loveland, 8 (USBS). Weld County: 20 mi. E Avalo, 3 (USBS); 8 mi. E Pawnee Buttes, 1 (USBS); Greeley, 1 (USBS). Morgan County: 30 mi. S Fort Morgan, 1 (UM). Logan County: Sterling, 8 (USBS). Adams County: Barr Lake, 4 (CMNH); 6 mi. E and 1 mi. N Denver, 1 (CMNH); 3 mi. NE Fitzsimons, 1 (CMNH). Washington County: Akron, 2 (UM). Lincoln County: Limon, 1 (USBS); Hugo, 1 (USBS). El Paso County: Colorado Springs, 2 (MVZ).

Dipodomys ordii extractus new subspecies

Type.—Male, adult, no. 76562, Museum of Vertebrate Zoology, University of California; 1 mi. E Samalayuca, 4500 ft., Chihuahua, Mexico; obtained on May 15, 1937, by William B. Richardson, original no. 2148.

Range.—Known only from the type locality.

Diagnosis.—Size medium (see measurements). Color pale, entire dorsal surface Pinkish Buff, purest on sides and flanks, dorsal surface but slightly suffused with black; pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail light-brownish. Skull medium in size; nasals long; rostrum relatively as well as actually wide; least interorbital breadth wide; auditory bullae relatively little inflated; braincase but slightly vaulted; external auditory meatus ovoid; zygomatic arches relatively robust and but slightly bowed laterad; pterygoid fossae subcircular; lacrimal processes small; foramen magnum deeply notched on dorsal border.

Comparisons.—From Dipodomys ordii ordii, D. o. extractus differs as follows: Size larger; color lighter; arietiform marks absent in D. o. extractus but pronounced in D. o. ordii; skull larger; rostrum wider; nasals longer; maxillary arches wider; auditory bullae more inflated laterally; braincase less vaulted; pterygoid fossae subcircular as opposed to circular; foramen magnum more deeply evaginated dorsally and ventrally.