Common Name

Scientific Name

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Utah Taxonomy

Hershler (no date) referred to this species as Pyrgulopsis new species 45, Pyrgulopsis new species 47, and (probably) Pyrgulopsis kolobensis. Hershler (1998) described this species as Pyrgulopsis transversa, for which he recommended the common name southern Bonneville pyrg.

The type locality for this species is "[s]prings south of Footes Canyon, Simpson Mountains, Old River Bed, Tooele County, Utah, T 10S, R 8W, NW 1/4 section 33"; the holotype, USNM 883221, was collected 12 May 1993.

No subspecies have been proposed in this species (i.e., the species is monotypic).

Status in Utah

This species is known from 6 springs, all being in north-central Utah. Four of these localities are in Tooele County, and there is 1 locality each in Utah County and in Sanpete County (Hershler 1998).

Hershler (no date) indicated the abundance of this species at 2 of the 6 known localities as "common" and at two others as "abundant". Despite the fact that it is "abundant" at two of the sites, the restriction of the species under consideration to 6 springs implies a very low population relative to other organisms.

Of the 6 known localities for this species (Hershler 1998), Hershler (no date) has provided information concerning the condition and threats at 5: Four of these sites are moderately disturbed, and one is highly disturbed. At 3 of the springs, livestock were present; there was also a residence near one of these springs. One of the springs had been dug out, and another possibly so, and both of these springs flow into reservoirs or an impoundments. Trampling by livestock and alteration of the springs are, then, known threats to the species. Population trend in this species is not known.

Inventory of other springs in the Tooele-Utah-Sanpete county area may be of value.

Habitats Utilized in Utah

Hershler (1998) wrote: "The type locality is a series of small, mineralized (1126 micromhos/cm) springs at about 1778 m elevation. The spring sampled is a small 'rheocrene' issuing out of a pipe ...." Hershler (no date) reported habitat information for 5 of the 6 known localities for this species, 1 of these 5 being the type locality already mentioned. He designated 4 of the springs rheocrenes and one a helocrene. Their elevations were reported as 5,830 to 6,740 ft. Their temperatures were 12, 12, 12, 13, and 16 degrees C, and their conductivities were 360, 463, 500, 889, and 1,126 micromhos/cm.


  • Text modified from: Oliver, George V. and William R. Bosworth III. 1999. Rare, imperiled, and recently extinct or extirpated mollusks of Utah[:] a literature review. Publication number 99-29. Utah Division of Wildlife Resources, Salt Lake City. 230 pp.