Class Amphibia
Order Anura
Family Scaphiopodidae
Applegarth (1979:94) indicated that although generally "associated with grasslands, the actual factors governing its distribution and relative abundance seem to be the combination of soft sandy alluvium, relatively warm summer temperatures, and summer rainfall." Absence during full-glacial times, then, is not surprising.
Johnson (1987), citing personal communication from Van Devender, distinguished the urococcyx from that of S. hammondii (currently recognized as S. multiplicata in our region) and S. bombifrons by the angle between the shaft and wing being greater in the latter two species; upper surface of vertebral portion reduced in those species but not in S. couchii; and cotyle being a flat oval.
Fig. 1 (left). Major skeletal elements of Scaphiopus couchii, modern specimen, and urococcyx of a modern Spea multiplicata. Upper row, left to right: ilium, tibiofibula, humerus, radioulna, femur, and coracoid; lower row, braincase, urococcyx of Scaphiopus couchii, and urococcyx of Spea multiplicata.
The urococcyx of the two genera is shown in Fig. 1 (both have abnormalities on their left sides as shown). The urococcyx of Spea multiplicata has been reversed and enlarged to better allow comparison.
Fig. 2 (right). Couch's Spadefoot (Scaphiopus couchii). Carl S. Lieb photograph.
Sites.
Sangamon: La Brisca (Van Devender et al. 1985).
Mid Wisconsin/Holocene: Shelter Cave (Brattstrom 1964: cf.).
Mid/Late Wisconsin: Animal Fair, F Grid (Applegarth 1979); Dark Canyon Cave (Applegarth 1979); Shafter Midden (UTEP).
Late Wisconsin/Holocene: Deadman Cave (Mead et al. 1984); Howell's Ridge Cave (Van Devender and Worthington 1977).
Literature. Applegarth 1979; Brattstrom 1964; Johnson 1987; Mead et al. 1984; Van Devender and Worthington 1977; Van Devender et al. 1985.
Last Update: 6 Nov 2013