Class Mammalia
Order Perissodactyla
Family Equidae
Equus sp.—Horses // Equus sp. (small)—Small Horse // Equus sp (large)—Large Horse // Equus calobatus—Stilt-legged Onager // Equus conversidens—Mexican Horse // Equus cumminsii—Cummings's Ass // Equus francisci—Stilt-legged Onager // Equus fraternus—Fraternal Horse // Equus niobrarensis—Niobrara Horse // Equus occidentalis—Western Horse // Equus simplicidens—Western Horse // Equus Species A—Unidentified Equus // Equus scotti—Scott's Horse
Horse nomenclature is a mess and has been for many years. The situation in the Southwest was discussed at some length by Harris and Porter (1980). A later study of Winans (1989) either clouded the issue or clarified it, depending on viewpoint. For a variety of reasons, the terminology utilized by Harris and Porter (1980) is used here, but the discussion below should be taken into consideration. Keep in mind that some specific names other than those recognized by Harris and Porter have been utilized in the literature since 1980.
Winans (1985, 1989) undertook a large-scale quantitative study of the genus Equus, which extends in the New World from the Blancan Pliocene to extinction at the end of the Pleistocene. She also considered the validity of a number of species names in her 1985 work (pertinent data are found in the species accounts).
Winans (1985) considered only four Pleistocene species of Equus to be valid: E. scotti, E. francisci, E. mexicanus, and E. alaskae. Of these, E. scotti and E. mexicanus were considered to be large horses, whereas E. francisci and E. alaskae were, relatively speaking, small; however E. francisci had elongated metapodials and E. alaskae relatively stout metapodials.
In her 1989 work, Winans shifted her conclusions somewhat. Rather than naming four Pleistocene species as valid, she recognized four groups that could be species or might consist of more than one species. These were the: Equus scotti group; Late Blancan to early Rancholabrean; middle west and a few sites in southernmost California, USA. Equus laurentius group; Rancholabrean; from all over the USA and from Mexico. Equus francisci group; Irvingtonian to Rancholabrean; middle west of the USA and Mexico. Equus alaskae group; Late Irvingtonian to Rancholabrean; Alaska, the middle west of the USA, and Mexico.
There appears to be three well marked morphological forms occurring fairly commonly across our region in the later Pleistocene: a large, a medium, and a somewhat smaller horse. There may be a fourth, stilt-legged horse appearing rarely. As indicated above, there are problems in applying names. The nomenclature here follows Harris and Porter (1980) except as otherwise noted, despite the quite possibly correct nomenclature proposed by Winans (1985, 1986).
Although most of the evolution of the family Equidae took place in North America, the family was eliminated from the continent in the terminal Pleistocene megafaunal extinction. Fiedel (2009) lists youngest dates for Equus as 10,870 ± 45, 11,210 ± 50, 11,330 ± 70, and 11350 ± 40 BP.
This page includes those without enough information to assign to any currently recognized species.
Literature.
Fiedel 2009; Harris and Porter 1980; Winans 1985, 1989.
Fossil horse material is relatively easy to identify to genus on many elements, but often very difficult to place to species. As a result, much equine material is recorded only as "horse" or "Equus sp."
The Pleistocene material earlier noted as from Skull Ridge (e.g., Harris 1993c) has been included in the Santa Cruz site, following Morgan and Lucas (2005).
Sites.
Pleistocene: Encino Blowouts (Agogino 1972); Floyd (Morgan and Lucas 2005); Fresnal Canyon (Morgan and Lucas 2006); Laguna (Morgan and Lucas 2005); Lazy E Ranch (Morgan and Lucas 2005); Moriarty (Morgan and Lucas 2005); Pecos River near Roswell (Morgan and Lucas 2005); Terlingua (Cockerell 1930).
Several areas of the map have far too many localities to be able to show them all.
Late Blancan: Cal Tech (Lindsay 1984); California Wash (Morgan and White 2005); Curtis Ranch (Lindsay 1984); Kelly Canyon (Morgan et al. 2011); Prospect (Johnson et al. 1975); San Simon Fauna (Morgan and White 2005); Snowflake (Lindsay and Tessman 1974).
Irvingtonian: El Paso (UTEP).
Early Irvingtonian: Domingo (Morgan and Lucas 2005); Fite Ranch (Morgan and Lucas (2003); Inman Gravel Pit (Morgan and Lucas 2005); Rincon Arroyo (Morgan and Lucas 2005); Tijeras Arroyo (Morgan and Lucas 2005).
Late Irvingtonian or Early Rancholabrean (?): Eighteenmile Bend (Morgan and Lucas 2005).
Rancholabrean: Alkali Flat (Morgan and Lucas 2005); Black Rock (Morgan and Lucas 2005); Boquillas Station (Mead et al. 2005); Cerro Colorado (Mead et al. 2005); Cerros Negros (Mead et al. 2005); Charley Day Spring (Lindsay and Tessman 1974); Choate Ranch (Mead et al. 2005); Davies Tank (Morgan and Lucas 2005); Dragoon Mountains (Mead et al. 2005); Empire South (Mead et al. 2005); Fenn Site (Mead et al. 2005); Fresnal Canyon (Harris 1993c); Guadalupita Canyon (Gillette et al. 1985); Hord Rock Shelter (Smith 1934); Joseph City (Mead et al. 2005); Keams Canyon (Lindsay and Tessman 1974); Lake San Agustín (Weber 1994); Lewis Site (Mead et al. 2005); Lindsay Ranch (Mead et al. 2005); Lynx Creek (Pasenko and Agenbroad 2012); Mesa Redonda (Morgan and Lucas 2005); Palomas Creek Cave (Harris 1993c); Placitas (Morgan and Lucas 2005); Santa Cruz (Morgan and Lucas 2005); San Rafael Aqueduct (Mead et al. 2005); Seff (Mead et al. 2005); Socorro (Morgan and Lucas 2005); Sonoita (Mead et al. 2005); South of Charleston (Lindsay and Tessman 1974); Springerville (McDonald et al. 2004); Tooth Cave (DeSaussure 1956); Tucson Brickyard (Mead et al. 2005); Whipple Gravel (Mead et al. 2005); Whitewater Draw (Mead et al. 2005); Willcox (Mead et al. 2004); Yeso Creek (Agogino and Stevens 1972).
Early/Early-Mid Wisconsin: Lost Valley (Harris 1993c).
Mid Wisconsin: CC:5:6 (Mead et al. 2003); Canez Wash [age may be incorrect] (Mead et al. 2005); Kartchner Caverns State Park (Carpenter and Mead 2003); Lehner Ranch (mammoth site) (Haynes 2008); Shonto (Agenbroad and Downs 1984).
Mid/Late Wisconsin: Rampart Cave (Wilson 1942); Sandblast Cave (Emslie 1988).
Late Wisconsin: Bonfire Shelter (Frank 1968); Conkling Cavern (Conkling 1932); Hermit's Cave (Harris 1993c); Hord Rock Shelter (Smith 1934); Lake Otero (UTEP); Lehner Site (mastodon site) (Mead et al. 1979); Lucy Site (Agogino 1972); McCullum Ranch (Morgan and Lucas 2005); Murray Springs (Hemmings 2007b); Muskox Cave (Logan 1981); Naco (Mead et al. 2005); Placitas (Morgan and Lucas 2005); Sheep Camp Shelter (Gillespie 1985); Stanton's Cave (Harington 1984); U-Bar Cave 15-18 ka (Harris 1989).
Late Wisconsin/Holocene: Beyond Bison Chamber (Harris 1970a); Deadman Cave (Mead et al. 1984); Pratt Cave (Lundelius 1979).
Literature.
; Agenbroad and Down 1984; Agogino and Stevens 1972; Cockerell 1930; Conkling 1932; DeSaussure 1956; Emslie 1988; Frank 1968; Gillespie 1985; Gillette et al. 1985; Harington 1984; Harris 1970a, 1989, 1993c; Harris and Porter 1980; Haynes 2008; Hemmings 2007b; Lindsay 1984; Lindsay and Tessman 1984; Logan 1981; Lundelius 1979; Mead et al. 1979; Mead et al. 1984; Mead et al. 2003; Mead et al. 2004; Mead et al. 2005; McDonald et al. 2004; Morgan and Lucas 2005; Morgan and White 2005; Morgan et al. 2011; Pasenko and Agenbroad 2012; Smith 1934; Weber 1994; Wilson 1942; Smith 1934 .
Since the common late Wisconsin small horses were Equus conversidens, it seems likely that this is the taxon represented; however, this is speculation only.
Sites.
Early Irvingtonian: Pajarito Springs (Morgan and Lucas 2005); Tijeras Arroyo (Morgan and Lucas 2005),
Rancholabrean: Shelton Canyon (Morgan and Lucas 2005).
Mid/Late Wisconsin: Shelter Cave (Harris 1993c).
Literature.
Harris 1993c; Morgan and Lucas 2005 .
The larger common late Wisconsin horse is E. niobrarensis, and this may well be the species represented here. As with the small horse, however, this is speculation only.
Sites.
Early Irvingtonian: Inman Gravel Pit (Morgan and Lucas 2005); Adobe Ranch (Morgan and Lucas 2003).
Rancholabrean: Shelton Canyon (Morgan and Lucas 2005).
Mid/Late Wisconsin: Shelter Cave (Harris 1993c).
Literature.
Harris 1993c; Morgan and Lucas 2003; Morgan and Lucas 2005.
This is considered a nomen dubium by Winans (1985). Cosgrove (1947) gives no information that would allow placement to any currently recognized species of our region.
Sites.
Pleistocene. Ceremonial Cave (Cosgrove 1947).
Literature.
Kurtén and Anderson (1980) viewed this species as belonging to the subgenus Asinus.
Sites.
Late Blancan: 111 Ranch (Morgan and White 2005: ?).
Literature.
Kurtén and Anderson 1980; Morgan and White 2005.
Last Update: 14 Mar 2013