Common Name
VARIABLE VERTIGO

Scientific Name
VERTIGO GOULDII

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Utah Taxonomy

In Utah this species as had a complex and very confusing nomenclatural history. Utah specimens have been called Vertigo coloradensis (Sterki 1892, Chamberlin and Jones 1929, Chamberlin and Berry 1929) and a race of that species, Vertigo coloradensis arizonensis (Chamberlin and Berry 1930); Vertigo columbiana var. utahensis (Sterki 1892) and Vertigo columbiana utahensis (Pilsbry and Vanatta 1900); Pupilla stoneri (in part: paratypes) (Chamberlin and Jones 1929); Vertigo gouldii arizonensis (Gregg 1941b, Gregg 1942, Chamberlin and Roscoe 1948); and Vertigo gouldi coloradensis (Pilsbry 1948) and Vertigo gouldii coloradensis (Chamberlin and Roscoe 1948). Thus, Utah specimens have been variously assigned to, or arranged as, a variety, 3 races, 4 species, and 2 genera.

Although Turgeon et al. (1988) listed this species (throughout its range) as "Vertigo gouldi", apparently following Pilsbry (1948), the correct spelling of the name is Vertigo gouldii (see Turgeon et al. 1998).

Two races of this species are believed to occur in Utah: Vertigo gouldii arizonensis and Vertigo gouldii coloradensis (see Chamberlin and Roscoe 1948).

Apparently all reported specimens of this species from southern Utah are of the race Vertigo gouldii arizonensis (see Chamberlin and Berry 1930 [as "Vertigo coloradensis arizonensis"], and especially Gregg 1941b and 1942).

Documentation of the race Vertigo gouldii coloradensis in Utah seems to be based on the specimen(s) collected by Henry Hemphill from "Box Elder Cañon, Utah, elevation 4500 feet" (Pilsbry and Vanatta 1900), also stated as "Box Elder canyon, northern Utah, at 4500 ft." (Pilsbry 1948).

Status in Utah

This species is known from 5 or 6 localities in Utah. All of these are historical and may even have been based material of prehistoric age; thus, the species is not known to be extant in Utah. Five of these locations are in 3 counties in southern Utah: Iron (Chamberlin and Jones 1929 as Pupilla stoneri, Chamberlin and Berry 1930 as V. coloradensis, Gregg 1941b), Garfield (Gregg 1942), and San Juan (Chamberlin and Berry 1929 as V. coloradensis, Chamberlin and Jones 1929 as V. coloradensis). The sixth locality, "Box Elder Cañon, Utah, elevation 4500 feet" (Pilsbry and Vanatta 1900 as V. columbiana) is ambiguous, there being 5 Box Elder Canyons in 5 counties in Utah, 4 in northern Utah and 1 in the extreme southern part of the state. Pilsbry nearly half a century later (1948) repeated this locality as "Box Elder canyon, northern Utah, at 4500 ft." Very likely this locality is the Box Elder Canyon east of Brigham City in extreme eastern Box Elder County. Yet a seventh geographical reference is not useful--"Utah" (Sterki 1892).

Although all useable records of this species in Utah are, as summarized above, from the southern part of the state, it is quite possible that the species occurs in other parts of the state. The species is known from the adjacent states of Arizona, New Mexico, and Colorado and from Montana and British Columbia as well as many other states and provinces north and east of Utah (see Pilsbry 1948).

Data reflecting abundance of this species in Utah have unfortunately not been reported by the various authors who have documented its occurrence in the state. All of the reports are historical and many may have been based on dead shells, perhaps very old (i.e., prehistoric); for example, the specimens reported by Chamberlin and Berry (1929) and repeated in Chamberlin and Jones (1929) were "weathered" and may well have been prehistoric.

Threats to this species in Utah are not known but likely are not great. Population trend of this species in Utah is not known; in fact, it is not known whether a population is extant in Utah.

Inventory is needed to determine whether this species is extant in Utah, and, if so, to ascertain its distribution and abundance. It should be looked for in southern Utah, from which it has been reported, as well as elsewhere in the state; its distribution outside of Utah suggests that it may occur in almost any part of the state except perhaps the West Desert region.

This species, like other members of its family, is minute, inconspicuous, and difficult to find. Thus, available information regarding its occurrence in Utah may not adequately represent its status in the state.

Habitats Utilized in Utah

At least 4, and possibly 6, of the specimens reported by Chamberlin and Jones (1929) in the type description of Pupilla stoneri were actually Vertigo gouldii (see Chamberlin and Roscoe 1948 and Pilsbry 1948). Chamberlin and Jones (1929) reported the habitat of their nominal "Pupilla stoneri" as in a "canyon, on the south side, near a tributary stream that had high banks. ... [Specimens were] found under leaves and under stones ...." However, several of their specimens, they noted, were "weathered", one "badly weathered", and thus may have been drift material washed into and down the stream bed from higher country. Thus, it is uncertain whether the habitat that they described accurately represents that inhabited by living individuals of Vertigo gouldii in Utah.

Gregg (1941b) characterized the area in which he collected a variety of mollusks, including Vertigo gouldii, as a "heavily forested rim which attains an altitude of 10,400 feet", "lofty forests of Engelmann spruce and alpine fir". Of one particular area where he focused his collecting and where he collected Vertigo gouldii, he wrote: "Here the altitude was 10,000 feet. There was a moderate amount of moisture most of the time and but a few yards away a series of springs in a swampy meadow formed brooklets which were tributaries to [a creek]."

Gregg (1942) described another area where he collected various gastropods, including Vertigo gouldii, "under pieces of rotten wood in well shaded places within a rather closely restricted area [near a creek]. The altitude at this point was about 8,000 feet."

Seemingly, this species has been found in Utah as low as 4,500 ft (see Pilsbry and Vanatta 1900, Pilsbry 1948).

Sources:

  • 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.

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