Main Menu

Class Mammalia
Order Rodentia
Family Sciuridae


Spermophile Ground Squirrels—Spermophile Ground Squirrels // Callospermophilus lateralis—Golden-mantled Ground Squirrel // Ictidomys/Xerospermophilus)—Ictidomys or Xerospermophilus Ground Squirrel // Ictidomys tridecemlineatus—Thirteen-lined Ground Squirrel // Otospermophilus beecheyi—California Rock Squirrel // Otospermophilus bensoni—Benson Rock Squirrel // Otospermophilus variegatus—Rock Squirrel // "Spermophilus" cochisei—Cochise Ground Squirrel // Urocitellus elegans—Wyoming Ground Squirrel // Xerospermophilus spilosoma—Spotted Ground Squirrel


Otospermophilus beecheyi (Richardson 1829)—California Ground SquirrelRegional Pleistocene distribution of Otospermophilus beecheyi

Synonyms. Spermophilus beecheyi


Late Blancan/Early Irvingtonian: Elsinore: Mimomys (Pajak et al. 1996: aff.).

?Irvingtonian/Rancholabrean: Emery Borrow Pit (Jefferson 1991b).

Rancholabrean: Harbor Freeway, Athens (Jefferson 1991b).

Sangamon: Newport Bay Mesa (Jefferson 1991b: cf.); San Pedro Lumber Co. (Jefferson 1991b).

Wisconsin: Costeau Pit (Jefferson 1991b).

Mid Wisconsin: McKittrick (Schultz 1937: cf.).

Mid/Late Wisconsin: Diamond Valley (Springer et al. 2009); Rancho La Brea (Stock and Harris).

Literature. Jefferson 1991a; Pajak et al. 1996; Schultz 1937; Springer et al. 2009; Stock and Harris 1992.


Otospermophilus bensoni (Gidley 1922)—Benson Ground SquirrelRegional Pleistocene distribution of Otospermophilus bensoni

Synonyms. Citellus bensoni, Spermophilus bensoni


Late Blancan: 111 Ranch (Morgan and White 2005: ?); California Wash (Morgan and White 2005); San Simon Fauna (Morgan and White 2005: ?).

Literature. Morgan and White 2005


Otospermophilus variegatus (Erxleben 1777)—Rock SquirrelRegional Pleistocene distribution of Otospermophilus variegatus

Synonyms. Citellus grammarus, Spermophilus grammarus, Spermophilus variegatus.

Dentaries of Sciurus aberti and Otospermophilus variegatusRock Squirrels look more like they should be tree squirrels than ground squirrels, and indeed it is not rare to see them climbing. They are about the size of our Southwestern species of Sciurus, and size alone will separate them from other regional ground squirrels .

The Rock Squirrel currently is distributed throughout the region, lowlands to high mountains, where rocky terrain or steep-banked arroyos occur, but are otherwise absent from desert and grassland (Findley et al. 1975).

Fig. 1. As seen here, Sciurus aberti (top) and Otospermophilus variegatus are very close in size. Dental characteristics and configuration of the dentary (especially the length and depth of the diastema) will separate the two. Characters of the posterior dentary also are quite different, but often missing in fossil material.

NPS photograph of Otospermophilus variegatusFig. 2. Rock Squirrel. National Park Service photograph by Sally King.


Medial Irvingtonian: SAM Cave (Rogers et al. 2000).

Rancholabrean: Papago Springs Cave (Czaplewski and Mead et al. 1999; Skinner 1942)

Early/Early Mid Wisconsin: Rm Vanishing Floor (Harris 1993c).

Mid Wisconsin: Screaming Neotoma Cave (Glennon 1994); U-Bar Cave (Harris 1987).

Mid/Late Wisconsin: Dark Canyon Cave (Tebedge 1988)

Late Wisconsin: Antelope Cave (Jefferson 1991b).

Mid/Late Wisconsin/Holocene: Jimenez Cave (Messing 1986); Sierra Diablo Cave (UTEP).

Late Wisconsin: Dust Cave (Harris and Hearst 2012); Murray Springs (Mead et al. 2005); Muskox Cave (Logan 1981); U-Bar Cave 14-15 ka (Harris 1989); U-Bar Cave 15-18 ka (Harris 1989); U-Bar Cave 18-20 ka (Harris 1989); Upper Sloth Cave (Logan and Black 1979); Vulture Cave (Mead and Phillips 1981).

Late Wisconsin/Holocene: Burnet Cave (Schultz and Howard 1935); Conkling Cavern (UTEP); Deadman Cave (Mead et al. 1984); Fowlkes Cave (Dalquest and Stangl 1984b); Kokoweef Cave (Jefferson 1991b); Pendejo Cave (UTEP); Stanton's Cave (Olsen and Olsen 1984); Williams Cave (Ayer 1936)

Literature. Ayer 1936; Czaplewski and Mead et al. 1999; Dalquest and Stangl 1984b; Findley et al. 1975; Glennon 1994; Harris 1987, 1989, 1993c; Harris and Hearst 2012; 1991b; Logan 1981; Logan and Black 1979; Mead and Phillips 1981; Mead et al. 1984, 2005; Messing 1986; Olsen and Olsen 1984; Rogers et al. 2000; Schultz and Howard 1935; Skinner 1942; Tebedge 1988.


Last Update: 21 Apr 2014