Vertigo (Vertigo) pygmaea (DRAPARNAUD, 1801)

Shell: Dextrous, whorls 4.5-5.4, most often 5.0. Shape ovate, from very short and broad to strongly elongate, spire tapered. Convexity of whorls and suture depth very variable. Aperture nearly semicircular. Teeth 4-7: columellar, in shape of a short fold or a knob; parietal, very short lamellate of variable height; upper and lower palatal, both high lamellate; angular and suprapalatal. Umbilicus open and deep but extremely narrow, or closed. Surface sculpture of very fine, poorly visible striae. Colour brown of varying intensity: from yellowish to chestnut, teeth white or whitish
Dimensions: Height 1.40-2.10 mm, breadth 0.95-1.20 mm, aperture height 0.43-0.55 mm, aperture breadth 0.55-0.75, body whorl height 1.00-1.20.
Ecology: Living in open habitats of a much varied humidity: grasslands from dry, sunny slopes with scarce vegetation (though never found on bare soil covered with debris only) to humid or even marshy meadows with lush plant cover, less frequent on sandy substratum than elsewhere; found among plant debris, on and under stones, on lowermost parts of grass blades. The only Vertigo in Poland found in habitats under strong anthropogenic pressure: gardens, pasture lands, balks, railway embankments.
Distribution: A Holarctic species inhabiting whole Europe except its southernmost and northernmost fringes: in Norway to 64°, Transcaucasia, central and northern parts of Asia. North America. Its southern distribution border is not exactly known; found in Spain, Yugoslavia, Bulgaria. In Poland it is the most common Vertigo, though never very abundant, in the mountains up to 1500 m a.s.l.