Sphincterochila
Sphincterochila boissieri ( Charpentier, 1847), type species of the genus Sphincterochila
The genus and family of the steppe snails ( Sphincterochila or Sphincterochilidae ) is a monotypic genus and family of the suborder of terrestrial snails ( gastropod ). The only genus of the family includes about 15 extant species. The oldest representative of the family are known from the late Eocene ( Paleogene ).
Features
The housings are globose to lenticular. The shell is relatively thick and pure white. With the exception of a few species, the housings are little carved. The umbilicus is moderately wide to be closed. However, the species are often highly variable. The sole is divided into three parts. The jaws are smooth, not ribbed, with z.T. a median projection. Atrium or vagina have an attachment that is probably as strong a modified dart sac to interpret. A love arrow is missing, it is a single gland mucus present.
Occurrence, lifestyle and dissemination
The species of the family live in rocky deserts and steppes and semi-arid areas. You are bound to calcareous soils and may experience extreme dryness and sunlight bear. The housing is closed by a Epiphragma. In dry Rigid it can take several years. They feed on algae and lichens that are grazed from the ground. The distribution of the family and the sole genus are arid coastal areas around the Mediterranean Sea and the coastal areas around the Red Sea.
System
The steppe snail family currently includes only one genus Sphincterochila, which is, however, divided by Schileyko in six subgenera. The name Albeidae Pallary, 1909 has really priority. He was replaced by Zilch because he. , The type genus Albea Pallary 1909 evaluated as a junior synonym of Sphincterochila Ancey, 1887
- Steppe snails ( Sphincterochilidae Zilch, 1960) Genus Sphincterochila Ancey, 1887 ( with subgenera Sphincterochila ( Sphincterochila ) Ancey, 1887, Sphincterochila ( Cariosula ) Pallary, 1910, Sphincterochila ( Zilchena ) Forcart, 1972 Sphincterochila ( Rima ) Pallary, 1910, Sphincterochila ( Albea ) Pallary, 1909, Sphincterochila ( Cerigottella ) Gittenberger, 1993) Andalusian steppe worm ( Sphincterochila baetica ( Rossmaessler, 1854) )
- Sphincterochila boissieri ( Charpentier, 1847)
- White steppe worm ( Sphincterochila candidissima ( Draparnaud, 1801) )
- Algerian steppe worm ( Sphincterochila cariosula ( Michaud, 1833) )
- Sphincterochila prophetarum ( Bourguignat, 1852)
Phylogeny
The position of the Sphincterochilidae within the Helicoidea has not yet been clarified. After the cladogram of Steinke, Albrecht & Pfenninger (2004) are the genera Cochlicella and Sphincterochila the sister taxon of Helicellinae within the Hygromiidae. Should these findings confirm that Sphincterochilidae and Cochlicellidae certainly can not be maintained as a family.
Helicellini
Cochlicella / Sphincterochila
Hygromiinae
Helicinae
Ariantinae
Helicodontidae
Bradybaenidae