IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group


BackLeiostyla gibba Lowe, 1852

Leiostyla gibba Lowe, 1852

  • Kingdom: Animalia
  • Phylum:
  • Class: Mollusca
  • Order: Gastropoda
  • Family: Lauriidae
CR Critically Endangered
IUCN Red List Status:

Countries of Occurrence:
Portugal - Madeira


Seddon, M.B.

Cameron, R., Groh, K., Cuttelod, A. & Neubert, E.


Facilitators / Compilers/s:

Assessment Rationale:

This species has not been recorded living for 150 years, and only two shells were known in 1878. Surveys have been carried out in suitable habitats and at the last known localities, but as yet no material has been found. The species is listed on the European Union Habitats Directive. Cook et al. (1993) described the stratigraphy of the Caniçal deposits finding that Leiostyla gibba was present in the early Holocene deposits, common in the late Holocene deposits (1600–200 years BP), and only one shell was found in the post-colonisation material. Thus, it is possible to infer that Leiostyla gibba may have disappeared from the peninsula between the late Holocene or even possibly after human colonisation. As other species have been refound in remote and less accessible areas after long time periods it has been listed as Critically Endangered, Possibly Extinct B1ab(iii) rather than Extinct.

Geographic Range:

This species is endemic to Madeira. It is common as a fossil in Quaternary deposits on Pta do São Lourenço. The only living records are from Ribeira de Sta Lucia by Wollaston (1878) and there are no records since despite frequent general surveys in 1920's, 1930's, 1970's, 1980's, 1990's and 2000's.

Portugal - Madeira
Extent of Occurrence (EOO):
Area of Occupancy (AOO):
Elevation Lower Limit:
Elevation Upper Limit:
Biogeographic Realms:
Endemic Madeira


There are no records since 1878 despite frequent general surveys in 1920's, 1930's, 1970's, 1980's, 1990's and 2000's.

Habitat and Ecology

This species was described as found in leaf-litter on rock ledges on tall cliffs.

Major Threat(s):

L. gibba has not been recorded for nearly 140 years, so it is assumed that degradation and loss in the last known habitats due to increasing urbanisation may have lead to the loss of this species.

Conservation Actions

This species is listed on the EU Habitats and Species Directive Annex II and the Council of Europe Bern Convention Appendix 2. Further survey work on required to determine if the species is still extant.