Pupilla triplicata
Tridentate dolls screw ( Pupilla triplicata )
The tridentate dolls screw ( Pupilla triplicata ) is a terrestrial snail from the family of dolls snails ( Pupillidae ).
Features
The housing is 2.2 to 2.8 mm ( very rarely to 4 mm) long and 1.4 mm wide ( thick). It is cylindrical in shape with six to seven whorls strongly arched and almost hemispherical rounded apex. The mouth is round to oblong - oval; the mouth rim is folded over and broadened, but quite thin and pointed. In the neck of the mouth is a powerful off-white bead. In the mouth usually extend into three teeth; a Parietalzahn, a Columellarzahn and a Palatalzahn. The Palatalzahn seems usually through the shell and is externally visible as a white line. Populations in Hungary always form only two teeth. The outside of the reddish- brown colored casing is nearly smooth, showing only a very fine Anwachsstreifung and shines by it.
Similar Species
Tridentate the screw is considerably smaller dolls and growth lines on the surface are generally finer than the other Pupilla species. The teeth are more than in the other lamellar Pupilla species.
Geographical distribution and habitat
The species occurs from the Pyrenees in the west, across the French and Swiss Alps, the Jura, a few isolated occurrences further north in France (southern Alsace, on the lower Meuse Valley ) and southern Germany (Southern Franconian Jura), Czech Republic, southern Poland, Austria to Croatia, Hungary and Bulgaria before. From there, the distribution area of the Carpathians, the Crimea Peninsula, northern Turkey, the Caucasus moves to central Asia ( Lake Baikal ) and the Altai. It is now also detected in Northwest Africa.
The species prefers grassy habitats on limestone or limestone scree overgrown sunny, dry and with Xerophile vegetation. It usually occurs between 300 and 1000 m above sea level, in Switzerland, but it was also found up to 2600 m altitude.
Threats and conservation
The populations at low levels in general are threatened by habitat destruction. In Rhineland -Palatinate, the species is already extinct. In Germany as a whole it is considered endangered.