Reference to the occurrence of this species in Utah, using its currently accepted name, has been made by Pilsbry (1948) and by Chamberlin and Roscoe (1948). Both of these sources provided explanations of another name that has, in part, been used for this species in Utah: Pupilla stoneri Chamberlin and Jones, 1929. Chamberlin and Jones (1929) described a purported new species Pupilla stoneri, which they called Stoner's snail, based on 7 specimens collected in Cedar Canyon, near Cedar City, Iron County. However, the holotype of Pupilla stoneri was determined to be Gastrocopta pilsbryana by Pilsbry (1948), who wrote: "Pupilla stoneri, of which I have examined the type ... is wholly typical G. pilsbryana." Apparently 4 paratypes were designated by Chamberlin and Jones (1929), but Chamberlin and Roscoe (1948) reported that the paratypes of Pupilla stoneri were actually Vertigo gouldii. Earlier Henderson (1936) also had indicated that Pupilla stoneri is a synonym of both Gastrocopta pilsbryana and Vertigo gouldii.
If the subspecies Gastrocopta pilsbryana amissidens is regarded as valid, then a type race Gastrocopta pilsbryana pilsbryana exists, which would be the race that occurs in Utah.
Status in Utah
Two occurrences of this species are known in Utah; however, both of these occurrences are historical (11 September 1929 [Chamberlin and Berry 1930], and 1929 or earlier [Chamberlin and Jones 1929]).
This species is known in Utah from 2 localities in the southern part of the state: one in Garfield County (Chamberlin and Berry 1930), the other in Iron County (Chamberlin and Jones 1929, reported as the holotype of "Pupilla stoneri" [paratypes of "Pupilla stoneri" are yet another species]; see Pilsbry 1948 and Chamberlin and Roscoe 1948).
Abundance data have not been reported for this species in Utah. Since there are only 2 records of the species in Utah, it is seemingly rare.
Threats to this species in Utah are not known; however, it is thought not to be very threatened in this state. No information is available regarding population trend of this species in Utah.
The seeming rarity of this species in Utah may be the result of inadequate sampling. Inventory is needed to determine whether this species is extant at the 2 Utah localities from which it is known historically as well as to determine extent of distribution and abundance in Utah, particularly the southern part of the state.
Habitats Utilized in Utah
Chamberlin and Jones (1929) wrote: "The seven specimens of Pupilla stoneri [only one of which is now known to be Gastrocopta pilsbryana] were found in a collection from Cedar Canyon, approximately ten miles from the mouth of the canyon, on the south side, near a tributary stream that had very high banks. It was found under leaves and under stones ...." The specimen of Gastrocopta pilsbryana was "a weathered gray", suggesting that it was a not only an empty shell, but also somewhat old, which raises the question of whether it was found in the habitat in which it had lived or whether, instead, it had been displaced--perhaps washed down the canyon from some other location and habitat.