Common Name

Scientific Name

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Utah Taxonomy

In an unpublished report to the BLM, Hershler (no date) referred to this species as Pyrgulopsis new species 39. Hershler (1998) has suggested the common name bifid duct pyrg for it.

The type locality of this species is "Spring, Maple Grove, Round Valley, Millard County, Utah, T 21S, R 2 1/2W, NW section 1." The holotype, USNM 883933, was collected 11 May 1995.

No subspecies have been proposed in this species.

Status in Utah

This species is known in Utah from 6 springs in Millard County; only 2 localities are known outside of Utah, these being in White Pine County, Nevada (Hershler 1998).

At 2 of the known Utah localities, this species has been reported to be "scarce"; at 3 other Utah localities it has been reported as "common" (Hershler no date). However, these terms were from a work dealing with springsnails in the Great Basin and very likely are not comparable to their use in other, less ecologically restricted groups. Since the species is known in Utah from only 6 springs, its overall abundance in this state should be considered quite low relative to most other kinds of organisms.

Only 1 of the Utah occurrences was considered by Hershler (no date) to be undisturbed. At 3 of the springs disturbance was "slight", and at one spring disturbance was "moderate" (Hershler no date). At these 4 disturbed springs, diversion of the spring was noted at one, livestock were present at another, and recreational use was evident at 3 others. Thus, trampling by livestock, water diversion, and recreational use are the known threats to this species in Utah. Population trend in Utah is not known.

Further inventory of springs in Millard County could perhaps reveal the presence of other populations of this species.

Habitats Utilized in Utah

Hershler (1998) described the habitat of the type locality as "a small, montane rheocrene". Hershler (no date) listed 5 of the Utah localities (including the type locality) as rheocrenes. Their temperatures were 9, 10, 10, 11, and 12 degrees C. Conductivities were reported for 4 of the springs: 317, 438, 458, and 622 micromhos/cm. The reported elevations of the springs were 6,150 to 7,470 ft.


  • 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.