Gopherus morafkai—Morafka's Desert Tortoise // Hesperotestudo sp.—Hesperotestudo Tortoises // Hesperotestudo wilsoni—Hesperotestudo Wilsoni
Members of the family are terrestrial and mostly large. Various giant tortoises of the Pleistocene are referred to this family as are the living species of Gopherus, such as Morafka's Desert Tortoise.
Identification of the Irvingtonian specimens are tentative (Vanderhill 1986), but represent a large tortoise. The Wisconsin specimens likely represent G. morafkai, but those listed here are insufficient for species identification. The Salt Creek specimen is only tentatively identified as Gopherus, but the elements appear consistent with those of that genus.
Fig. 1. A peripheral element from the carapace of a large tortoise (cf. Gopherus) from the vicinity of La Union, Doña Ana Co., NM. UTEP 33-12. Metric scale.
Fig. 2. Dorsal and ventral views of two elements of a large chelonian from Salt Creek.
Late Blancan: Caballo (Morgan et al. 2011).
Early Irvingtonian: El Paso (UTEP: ?); Adobe Ranch (Morgan and Lucas 2005).
Mid Wisconsin: U-Bar Cave (UTEP: cf.).
Late Wisconsin: Salt Creek (UTEP: cf.); U-Bar Cave 13-14 ka (Harris 1989: cf.); U-Bar Cave 14-15 ka (Harris 1989); U-Bar Cave 18-20 ka (Harris 1989).
Late Wisconsin/Holocene: Conkling Cavern (Brattstrom 1964).
Literature. Brattstrom 1964; Harris 1989; Morgan and Lucas 2005; Morgan et al. 2011; Vanderhill 1986.
Fig. 1. Morafka's Desert Tortoise. Photograph by Jeff Servoss, courtesy of the U.S. Fish & Wildlife Service.
Synonyms. Gopherus agassizii (part). According to Murphy et al. (2011), Gopherus agassizii occurs only west and north of the Colorado River. The tortoises east and south of the Colorado River, previously also considered to represent G. agassizii, instead represent a separate species, G. morafkai.
It's long been known that the tortoises of the Mojave Desert and those of the Sonoran Desert differ in morphology and behavior. Murphy et al. (2011) clarified nomenclatural problems and named the taxon east and south of the Colorado River as a new species.
Discussion. Today, Morafka's Tortoise is primarily limited to the Sonoran Desert. However, tortoises apparently conspecific to the Sonoran species extended far to the east during at least two times in the Wisconsin and apparently at least once earlier in the Rancholabrean (Pate 2002). Remains from Slaughter Canyon Cave, presumably from the same level as the extinct bat Tadarida constantinei, would be in excess of 209 ± 9 ka (Lundberg and McFarlane 2006; Pate 2002). At Pendejo Cave, remains are found in Zone M, radiocarbon dated at about 35,500 ka, and in Zone C, which includes both terminal Wisconsin and Holocene material. Although the Dry Cave occurrences could also pertain to the ca. 35 ka date, they may be older. The other occurrences east of the present range are terminal Wisconsin with some possibility of Holocene presence. Dates on tortoise epidermal scutes from Shelter Cave (Thompson et al. 1980) range from 12,250 ± 200 (A-1728) to 11,130 ± 500 (A-2141) radiocarbon years B.P.
Brattstrom (1964) noted that many of the bones from Shelter Cave were burned.
In view of its apparent present inability to withstand the periodic hard freezes now typical of even southern New Mexico, Harris (1987) used its presence in conjunction with other taxa to infer mild winters during the times it occurred in our region.
Fig. 2. Gopherus morafkai from the Room of the Vanishing Floor, Dry Cave, Eddy County, NM. UTEP 27-88.
The Pleistocene situation in the Lower Grand Canyon region is unclear. Pending clarification, occurrences from the area are considered to pertain to Gopherus morafkai, but the uncertainty should be recognized.
Rancholabrean: Slaughter Canyon Cave (Pate 2002).
Early/Early-Mid Wisconsin: Rm Vanishing Floor (Van Devender et al. 1976); Sabertooth Camel Maze (Van Devender et al. 1976).
Mid Wisconsin: Pendejo Cave (Harris 2003); Vulture Cave (Mead 2005: 33,600 ± 1,000 BP to 29,810 ± 1,980 BP).
Mid/Late Wisconsin/Holocene: Sierra Diablo Cave (UTEP); Shelter Cave (Brattstrom 1964).
Late Wisconsin: Muav Gate (Mead 2005: 12,430 ± 270 BP); Rampart Cave (Mead 2005: 16,330 ± 270 BP to 12,230 ± 350 BP); Vulture Canyon (Van Devender et al. 1977a); Vulture Cave No. 8 (Mead 2005: 13,820 ± 220 BP)
Late Wisconsin/Holocene: Conkling Cavern (Brattstrom 1961); Pendejo Cave (Harris 2003); Robledo Cave (Van Devender et al. 1976: cf.)
Literature. Brattstrom 1961, 1964; Harris 1987, 2003; Lundberg and McFarlane 2006; Mead 2005; Murphey et al. 2011; Pate 2002; Thompson et al. 1980; Van Devender et al. 1976, 1977a.
Synonyms. Geochelone, Testudo.
Vanderhill (1986) reported fragmentary material from the Rio Grande Valley-edge deposits in extreme southern New Mexico, tentatively identified to this taxon because of their large size, but the possibility of a large species of Gopherus was noted. A fragmentary specimen (identified as Testudo) from the Gray Sand at Blackwater Loc. No. 1 was thought by Lundelius (1972) to have been redeposited from older beds, and is not included here.
Late Blancan: Caballo (Morgan et al. 2011); California Wash (Lindsay 1978); Curtis Ranch (Brattstrom 1955); Virden (Morgan and Lucas 2003).
Early Irvingtonian: Adobe Ranch (Morgan and Lucas 2005); Tijeras Arroyo (Morgan and Lucas 2005).
Rancholabrean: Cerro Colorado (Mead et al. 2005).
Literature. Brattstrom 1955; Lindsay 1978; Lundelius 1972; Mead et al. 2005; Morgan and Lucas 2003, 2005; Morgan et al. 2011; Vanderhill 1986.
Synonyms. Geochelone wilsoni, Testudo wilsoni.
Wilson's Tortoise is the smallest of a wide variety of Cenozoic species of Hesperotestudo. It appears to be a Wisconsin form distributed from Texas and Oklahoma to eastern New Mexico (Johnson 1987). Dry Cave is the westernmost locality for Wilson's Tortoise and it is associated with the easternmost occurrence of Gopherus morafkai (Van Devender et al. 1976). At Lubbock Lake, TX, and at Blackwater Draw, it apparently survived until Clovis times (Moodie and Van Devender 1979).
Fig. 1. Carapace elements (5-245) from the Sabertooth Camel Maze, Dry Cave. UTEP specimens.
Moodie and Van Devender (1979) speculated that presence of this taxon implies an absence of prolonged hard frosts.
Early/Early-Mid Wisconsin: Sabertooth Camel Maze (Van Devender et al. 1976).
Late Wisconsin: Blackwater Draw Fauna (Brown Sand Wedge) (Slaughter 1975: cf.).
Literature. Johnson 1987; Moodie and Van Devender 1979; Slaughter 1975; Van Devender et al. 1976.
Last Update: 4 Mar 2013