Genera, subgenera and species of the Cochlostomatidae (Gastropoda, Caenogastropoda, Cochlostomatidae)

The generic taxonomy of the family Cochlostomatidae (Gastropoda, Caenogastropoda) is revised on the basis of shell and genital tract morphology, and molecular data. Five genera are distinguished, viz. Imerezia gen. nov., Toffolettia Giusti, 1971, Rhabdotakra A.J. Wagner, 1897, Obscurella Clessin, 1889, and Cochlostoma Jan, 1830. These taxa differ in details of the genitalia and the shells. They are well separated clades according to the DNA analyses of the nuclear H3 and mitochondrial 16S ribosomal markers. Imerezia gen. nov. and Toffolettia are monotypic. Obscurella has radiated in SW Europe, mainly in the Pyrenees and the Cantabrian mountains. Cochlostoma shows a vicariant radiation in central and eastern Europe, mainly in the Alps, the Appennines, the Dinarids and the Greek mountains. Cochlostoma is by far the most speciose genus. It is subdivided here into 8 subgenera, viz. Cochlostoma s. str., Turritus Westerlund, 1883, Auritus Westerlund, 1883, Eupomatias Wagner, 1897, Lovcenia subgen. nov., Dalfreddia subgen. nov., Wagneriola subgen. nov., and Clessiniella subgen. nov., corresponding with clades resulting from the DNA analysis. Most of these subgenera can also be diagnosed on the basis of a combination of features of the female genital tract and shell morphology. Some European and most of the African species could not be investigated because of lack of material for dissection and sequencing. The genus Obscurella especially needs to be studied in more detail.