''Caseolus sphaerula'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of small

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial gastropod mollusks that have shells (those without shells are known as ...

, a

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

pulmonate Pulmonata or pulmonates, is an informal group (previously an order, and before that a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includ ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

. The specific epithet is spelled ''sphaerulus'' in both of the references here cited, however the species is also often referred to as ''C. sphaerula'', for example in the Convention of Berne and the

Habitats Directive The Habitats Directive (more formally known as Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora) is a directive adopted by the European Community in 1992 as a response to the Berne Convention. The E ...

. The species was named as ''Helix (Caseolus) sphaerula''. In Latin,"sphaerula" is a noun meaning "little sphere", so it does not change ending.

Distribution and conservation status

This species of land snail lives in

Madeira ) , anthem = ( en, "Anthem of the Autonomous Region of Madeira") , song_type = Regional anthem , image_map=EU-Portugal_with_Madeira_circled.svg , map_alt=Location of Madeira , map_caption=Location of Madeira , subdivision_type=Sovereign st ...

on dry, stony ground. It is mentioned in annexes II and IV of the

. This species is threatened by forest replanting, mixed forms of pollution, erosion and the impact of improved access to its habitat. Its future prospects are bad and the species is likely to become extinct in its biogeographical region.Report on the main results of the surveillance under article 11 for annex II, IV and V species (Annex B) Factsheet : Caseolus sphaerula
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References

In Falkner, M., Groh, K. & Speight, M. C. D. (eds) Collectanea Malacologica, Festschrift für Gerhard Falkner Conchbooks, Hackenheim, pp. 89–235. *Cook, L. M., Goodfriend, G. A. & Cameron, R. A. D. 1993. Changes in the land snail fauna of eastern Madeira during the Quaternary. Phil. Trans. R. Soc. Lond. B, 339, 83-103 *Cameron, R. A. D. & Cook, L. M. (1996). Diversity and durability: responses of the Madeiran and Porto-Santan snail faunas to natural and human-induced environmental change. American Malacological Bulletin, Vol. 12(1/2), 3-12. *Paiva, C. 1867. Monographia Molluscorum Terrestrium Fluvialium, Lacustrium Isularium Maderensium, Mem. Acad. R. Sci. Lisboa, Cl. Sci. Math. Phys. Nat., N. S. 4 (1): 46. sphaerulus Gastropods described in 1852 {{Geomitridae-stub

Distribution and conservation status

References

Further reading