Mollusca : Gastropoda : Stylommatophora : VertiginidaeSnails and slugs

Vertigo pusilla O. F. Müller, 1774

Wall Whorl Snail

Vertigo pusilla

Description: Sinistral. Larger than the only other sinistral species of Vertigo, V. angustior. Shell yellowish-brown to mid brown, nearly smooth but with fine growth lines i.e. paler and smoother than angustior. Aperture filled with 6-9 denticles. 1.7 - 2.0 mm.

World Distribution: Distribution European boreo-temperate (53).

Irish Distribution: Very localised and rare. Widespread as a subfossil in sand dune deposits on the north coasts of Antrim and Londonderry (Welch, 1898). Most of the surviving Irish sites are in Co. Clare on Carboniferous limestone. In the northern half of Ireland seen recently only at Sheskinmore Lough, West Donegal. Historically recorded from Whitepark Bay, Co. Antrim (Standen, 1897), Grogan's Glen, Belfast (specimens in UM, G. C. Hyndman, 1833; MN2048) and at Colin Glen, Belfast (W. Thompson, 1837) but appears gone from these localities now.

Ecology:

  • Found in sheltered and warm, rather open sites in woods, scrub or undisturbed rough pasture
  • South-facing chalk or limestone slopes and sand dunes are also favoured
  • Certainly in decline but possibly under-recorded

Key Identification Features:

  • Sinistral but larger than V. angustior
  • Shell nearly smooth, yellowish-brown
  • Apertural denticles 6-9: 2 parietal; 2 columellar; 3 palatal, two of which are very long
  • Very rare, mainly on old, undisturbed limestone scrub or rough pasture

Red list status:

  • Endangered (EN)

Distribution Map from NBN: Vertigo pusilla at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Vertigo pusilla at iNaturalist World Species Observations database.

GBIF data for Vertigo pusilla | Classification: Gastropoda, Stylommatophora, Vertiginidae, Vertigo

Thumbnails for genus Vertigo

 Anderson, R., 2024. Vertigo pusilla. O. F. Müller, 1774. [In] MolluscIreland.
https://www2.habitas.org.uk/molluscireland/species.php?item=199. Accessed on 2024-12-26.