Vertigo hubrichti variabilis n. subsp.
Variable Pleistocene Vertigo
Vertigo hubrichti variabilis
Basis for Former Listing
The variable Pleistocene vertigo is a rare landsnail with a limited distribution in southeastern Minnesota and southwestern Wisconsin through northeastern Iowa. In Minnesota this subspecies is found in Fillmore and Olmsted counties. This taxon was widespread during the Wisconsin glaciation (>12,000 years ago), but now survives only as small relict populations with very specific habitat requirements. The rarity of this species led to its classification in Minnesota as threatened in 1996.
Basis for Delisting
Taxonomic work based on shell morphology and genetic data has determined that V. hubrichti variabilis cannot be considered a distinct species, but simply a different morphologic shell form of the diverse species V. arthuri, a more widespread species in Minnesota. Thus, a status of threatened is no longer necessary. The variable Pleistocene vertigo was delisted in 2013.
References and Additional Information
Frest, T. J. 1991. Summary status reports on eight species of candidate land snails from the driftless area (Paleozoic Plateau), Upper Midwest. Final report submitted to the U.S. Fish and Wildlife Service, Region 3. 54 pp.
Minnesota Department of Natural Resources. 2012. Statement of need and reasonableness. Minnesota Department of Natural Resources. Division of Ecological and Water Resources. St. Paul, Minnesota. 337 pp.
Ostlie, W. R. 1990. Completion of the algific slope/maderate cliff landsnail survey in Minnesota. Final report submitted to the Division of Ecological Services, Minnesota Department of Natural Resources, St. Paul.. Unpaged.