Vertigo hubrichti variabilis n. subsp. | Variable Pleistocene Vertigo |
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SynonymsVertigo hubrichti variabilis Basis for Former ListingThe 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 DelistingTaxonomic 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. |
