Clausiliidae, also known by the common name door snails, is a taxonomic family of small, very elongate, mostly left-handed, air-breathing land snails, sinistral terrestrial pulmonate gastropod mollusks. With over 1700 recognized recent and fossil species, this is among the most diverse families of terrestrial gastropods (cf. Orthalicidae), although the marine gastropod family Pyramidellidae is larger. Most species of Clausiliidae have an anatomical structure known as a clausilium, which enables the snail to close off the aperture of the shell with a sliding "door".

Shell description

Almost all the species of snails in the family of door snails are left-handed, which is an uncommon feature in gastropod shells in general. These snails have shells which are extremely high-spired, with numerous whorls. The shells tend to be club-shaped, tapering at both ends to a rounded nub. The aperture usually has visible folds.

The clausilium

Clausiliids are also very unusual among pulmonate gastropods in that most of them have a "door" or clausilium. The clausilium is not the same thing as an operculum, which does not exist at all in pulmonate gastropods. The clausilium is a calcareous structure, tongue-shaped or spoon-shaped, which can close the aperture of the snail shell to protect the soft parts against predation by animals such as carnivorous beetle larvae. The narrow end of the clausilium slides in the grooves that are formed by the folds on the inside of the shell.

Anatomy

In this family, the number of haploid chromosomes lies between 21 and 30 (according to the values in this table).

Taxonomy

The type genus is Clausilia Draparnaud, 1805. The family Clausiliidae is classified within the informal group Sigmurethra, itself belonging to the clade Stylommatophora within the clade Eupulmonata (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).

2005 taxonomy

The taxonomy of the Gastropoda by Bouchet & Rocroi, 2005 recognizes subfamilies as follows: subfamily Clausiliinae Gray, 1855 subfamily Alopiinae A. J. Wagner, 1913 subfamily † Constrictinae H. Nordsieck, 1981 subfamily Garnieriinae C. Boettger, 1926 subfamily † Eualopiinae H. Nordsieck, 1978 subfamily Laminiferinae Wenz, 1923 subfamily Mentissoideinae Lindholm, 1924 subfamily Neniinae Wenz, 1923 - Neniastrinae H. B. Baker, 1930 subfamily Phaedusinae A. J. Wagner, 1922 subfamily Serrulininae Ehrmann, 1927

Genera

Genera include:

Clausiliinae

Tribe Acrotomini H. Nordsieck, 1979 tribe Baleini Tribe Boettgeriini H. Nordsieck, 1979 tribe Clausiliini Tribe † Emarginariini H. Nordsieck, 2007 Tribe Euxinellini Neubert, 2002 Tribe Filosini H. Nordsieck, 1979 tribe Gracillariini H. Nor dsieck, 1979 Tribe Mentissoideini Lindholm, 1924 Tribe Olympicolini Neubert, 2002 Tribe Strigileuxinini H. Nordsieck, 1994 Tribe Strumosini H. Nordsieck, 1994

Alopiinae A. J. Wagner, 1913

Alopiinae tribe Alopiini tribe Cochlodinini Lindholm, 1925 (1923) tribe Delimini R. Brandt, 1956 tribe Medorini H. Nordsieck, 1997

Constrictinae

Fossil subfamily Constrictinae contains genera:

Eualopiinae

Fossil subfamily Eualopiinae contains genera: Tribe † Eualopiini H. Nordsieck, 1978 Tribe † Rillyini † H. Nordsieck, 1985

Garnieriinae

Laminiferinae

Tribe Laminiferini Wenz, 1923 Tribe † Oospiroidesini H. Nordsieck, 2007 Tribe † Polloneriini H. Nordsieck, 2007

Mentissoideinae

synonym of the tribe Mentissoideini Lindholm, 1924 (superseded classification)

Neniinae Wenz, 1923

Tribe Neniini Wenz, 1923

Peruiniinae H. Nordsieck, 2005

Phaedusinae A. J. Wagner, 1922

Tribe † Disjunctariini H. Nordsieck, 2014 Tribe † Nordsieckiini H. Nordsieck, 2007 tribe Phaedusini A. J. Wagner, 1922 Tribe † Serrulellini H. Nordsieck, 2007 Tribe Serrulinini Ehrmann, 1927 Tribe Synprosphymini H. Nordsieck, 2007

Synonyms

Conservation

Although non-marine molluscs appear to be exceptionally vulnerable to extinction, the IUCN Red list listed only 9 species from this family.