Wollastonaria turricula explained

Wollastonaria turricula is a species of small, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Geomitridae.^[1]

This species is indigenous to the Madeira archipelago, where it only occurs on the islet Ilhéu de Cima.

Shell description

The shell of these snails is shaped like a discus, or a lens, with a sharp edge around the periphery of the whorls.^[2] It may be easily distinguished, through external morphology, from all Hystricella and Wollastonia species from its "peculiarly turreted shell".^[3]

Distribution and Ecology

Hystricella turricula is endemic to the coastal slopes and plateaus on the islet Ilhéu de Cima on the southeastern coast of Porto Santo. The species occurs under volcanic rocks and debris scattered in open fields. The local form pererosa occurs on steep low-elevation slopes. Referenced collecting localities of De Mattia, Neiber & Groh, 2015 include: Quaternary slope deposits on the southwestern coast of Ilhéu de Cima, 33°03'15"N 16°17'02"W, 40 m; Ilhéu de Cima, top, under stones, 33°03'13"N 16°16'48"W, approx. 100 m.

Conservation status

This species is mentioned in annex IV of the Habitats Directive. De Mattia, Neiber & Groh, 2015 consider this species to be Critically Endangered under criteria B1a,b(ii,v),2a,b(ii,v), as the species' extent of occurrence is less than 1 km², and is imperiled by grazing and various unrecorded factors. Significant populational declines have been recorded, and the species is now restricted to one location on a high-altitude plateau.

External links

• Lowe, R. T. (1831). Primitiae faunae et florae Maderae et Portus Sancti; sive species quaedam novae vel hactenus minus rite cognitae animalium et plantarum in his insulis degentium breviter descriptae. Transactions of the Cambridge Philosophical Society. 4 (1): 1-70, pl. 1-6. Cambridge
• De Mattia, W., Neiber, M. & Groh, K. (2018). Corrigenda: De Mattia W, Neiber MT, Groh K (2018) Revision of the genus-group Hystricella R. T. Lowe, 1855 from Porto Santo (Madeira Archipelago), with descriptions of new recent and fossil taxa (Gastropoda, Helicoidea, Geomitridae). ZooKeys 732: 1–125. https://doi.org/10.3897/zookeys.732.21677. ZooKeys. 733: 147-148

Notes and References

1. MolluscaBase eds. (2022). MolluscaBase. Wollastonaria turricula (R. T. Lowe, 1831). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1340237 on 2022-07-21
2. The anatomy and general affinities of Ochthephila (= Geomitra) turricula (Lowe). Hugh Watson. Proceedings of the Malacological Society of London. 15. 6 . 1923. 283–93.
3. Mattia. Willy De. Neiber. Marco T.. Groh. Klaus. 2018-01-24. Revision of the genus-group Hystricella R. T. Lowe, 1855 from Porto Santo (Madeira Archipelago), with descriptions of new recent and fossil taxa (Gastropoda, Helicoidea, Geomitridae). ZooKeys. en. 732. 1–125. 10.3897/zookeys.732.21677. 29416404. 5799741. 1313-2970. free.