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Class Amphibia
Order Anura
Family Bufonidae


Incilius alvarius—Sonoran Desert Toad // Incilius mazatlanensis—Sinaloa Toad // Incilius nebulifer—Coastal Plain Toad

Incilius alvarius (Girard 1859)—Sonoran Desert ToadDistribution of fossil Incilius alvarius

Synonyms. Bufo alvarius, Cranopsis alvaria, Ollotis alvaria.

Incilius alvarius photo by Jeff Servoss, U.S. Fish and Wildlife ServiceToday, the Sonoran Desert Toad just barely makes it into the extreme southwestern tip of New Mexico's bootheel on the east, where the Yaqui River drainage enters New Mexico, but inhabits most of the southern half of Arizona. The only fossil New Mexican record for the area is relatively close to the eastern limits, at U-Bar Cave. A large permanent spring is within several miles of the cave today and Pleistocene Playas Lake occurred to the northwest, both likely presenting suitable habitat.

Fig. 1. Incilius alvarius. Photograph courtesy of Jeff Servoss and U.S. Fish and Wildlife Service.

This is a very large toad, as can be seen in Fig. 2, where a partial tibiofibula is compared to the same element tentatively identified as that of Anaxyrus woodhousii.

Two specimens of fossil Incilius alvarius compared to Anaxyrus ? woodhousii

Fig. 2. U-Bar Cave specimens of Incilius alvarius. A partial tibiofibula (center) (U-Bar Cave, 5689-1-158) is compared to the same element in a moderately large toad (Anaxyrus ? woodhousii, 5689-73-29) (right) from the same site. The vertebra (5689-140-59) is shown from the anterior (top) and in dorsal aspect.


Late Blancan: California Wash (Lindsay 1984).

Irvingtonian: El Golfo (Croxen et al. 2007).

Sangamon: La Brisca (Van Devender et al. 1985).

Mid Wisconsin: U-Bar Cave (UTEP).

Late Wisconsin: U-Bar Cave 15-18 ka (Harris 1989).

Literature. Croxen et al. 2007; Harris 1989; Lindsay 1984; Van Devender et al. 1985.


Incilius mazatlanensis (Taylor 1940)—Sinaloa ToadDistribution of fossil Incilius mazatlanensis

Synonyms. Bufo mazatlanensis, Cranopsis mazatlanensis.


Sangamon: La Brisca (Van Devender et al. 1985).

Literature Cited. Van Devender et al. 1985.


Incilius nebulifer, photo by Dana Drake, Amphibian Research and Monitoring Initiative, USGS Incilius nebulifer (Girard 1854)—Coastal Plain ToadDistribution of fossil Incilius nebulifer

Synonyms. Bufo valliceps, Bufo nebulifer, Cranopsis nebulifer, Ollotis nebulifer.

The Fowlkes Cave record apparently is about 150 km north-northwest of the nearest present-day occurrence in Brewster County, Texas (Parmley 1988).

Fig. 1. Incilius nebulifer. Photograph courtesy of Dana Drake, Amphibian Research and Monitoring Initiative, U.S. Geological Survey.


Late Wisconsin/Holocene: Fowlkes Cave (Parmley 1988).

Literature. Parmley 1988.


Last Update: 15 May 2014