The first Durango alterna, and still one of only a handful of specimens known, taken by Ernest Tanzer in 1969 and reported in Tanzer (1970). Photo courtesy of Troy Hibbitts. 
Adult alterna from the Sierra Madre Occidental of northwestern Durango, 7600 ft (2315 m) elev. Copyright 2007 Jason Jones
Adult alterna from the Sierra Madre Occidental of northwestern Durango, 7600 ft (2315 m) elev.
Adult alterna from the Sierra Madre Occidental of northwestern Durango, 7600 ft (2315 m) elev. 
Adult alterna from the Sierra Madre Occidental of northwestern Durango, 7600 ft (2315 m) elev.
This young alterna was found during a herpetological survey of the Sierra el Sarnoso (listed on some maps as Sierra del Sarnoso) of northeastern Durango, just W of the border with Coahuila, and just N of the city of Gomez Palacio. Refer to Gadsden et al. (2006) for details. Photo courtesy of Sandra Leyva-Pacheco.
Adult alterna from the Sierra Madre Occidental of northwestern Durango, 7600 ft (2315 m) elev.
Adult alterna from the Sierra Madre Occidental of northwestern Durango, 7600 ft (2315 m) elev. Copyright 2007 Jason Jones
