Talussnail - Illustration by Bill Singleton



The talussnail is a rock snail usually found in taluses or "slides" of coarse broken rock. The snails are generally found in crevices one to several feet below the surface, sealed to stones by their mucus. The shell is usually thin and globular. The shells of Sonorella are weakly differentiated, and species are usually separated by location and male genitalia. The shell of the talussnail averages over half an inch tall and almost an inch wide. Sonorella are distributed from Arizona, southern New Mexico, western Texas, and southward into northwestern Chihuahua and northeastern Sonora. They can be found from arid, lower elevation foothills to wooded canyons at elevations of 8,000 to 10,000 feet.

Talussnails in Pima County: Talussnails generally have a very narrow range and are usually restricted to a particular mountain range. Destruction or disturbance of talus slopes may lead to the extinction of a talussnail species. Listed below are several talussnail species known only from Pima County.


Bagnara's Talussnail
Sonorella bagnarai

Range/Habitat: The Bagnara's talussnail is found in the Rincon Mountains, below the northeast summit of Rincon Peak, at an elevation of 8,000 to 8,200 feet.


Kitt Peak Talussnail
Sonorella xanthenes

Range/Habitat: The species is found near the top of Kitt's Peak, in a humid area at the foot of cliffs. The area is near the head of a stream, under scattered rocks among sticks and leaves in oak brush, at an elevation of 5,500 feet. It has also been collected in several ravines of the north slope of the Peak at elevations ranging from 6,200 to 6,700 feet.


Papago Talussnail
Sonorella papagorum

Range/Habitat: This species is located in Black Mountain, nine miles south of Tucson. The snail is found deep within slopes covered with slides of black basalt at an elevation on 3,200 feet. Vegetation found near the slopes consists of ocotillo, mesquite, cat-claw, and palo verde.



1. Pilsbry, Henry A. 1939. "Land Mollusca of North America." The Academy of Natural Sciences of Philadelphia. Vol.1 Part

2. Bequaert, J. and W. Miller. 1973. The Mollusks of the Arid Southwest, with an Arizona Checklist. Tucson University of Arizona Press. Vol.1 Part

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