Chondrinidae, Steenberg, 1925

Kokshoorn, Bas & Gittenberger, Edmund, 2010, Chondrinidae taxonomy revisited: New synonymies, new taxa, and a checklist of species and subspecies (Mollusca: Gastropoda: Pulmonata) 2539, Zootaxa 2539 (1), pp. 1-62 : 5

Chondrinidae C.-M. Steenberg, 1925

The subdivision of the land snail family Chondrinidae into four subfamilies, viz. Chondrininae , Gastrocoptinae, Hypselostomatinae and Aulacospirinae, by Zilch (1959), does not reflect the phylogenetic relationships of these taxa. For that and other reasons these four taxa have currently been raised to family status ( Wade et al. 2006; Tongkerd et al. 2004). Here we accept that classification. As a consequence, the family Chondrinidae is restricted to the six (western) Palaearctic genera Granaria Held, 1837 , Granopupa Boettger, 1889 , Solatopupa Pilsbry, 1917 , Chondrina Reichenbach, 1828 , Abida Turton, 1831 , and Rupestrella Monterosato, 1894 . These genera are quite different in speciosity and biogeographically.

Molecular studies ( Wade et al. 2001, 2006; Kokshoorn 2008: 21–40) have shown that there exists a deep phylogenetic split within the Chondrinidae (fig. 1). There is a clade containing Granaria , Granopupa and Solatopupa , next to a clade containing the genera Chondrina , Abida and Rupestrella . Whereas Granaria , Granopupa and Abida are genera with ground-dwelling snails, Solatopupa , Chondrina and Rupestrella species occur on vertical, exposed rock faces. Thus in both clades species with contrasting habitat preferences occur. The clades might have evolved because of, or in conjunction with, a shift in habitat choice. If so, then we have to accept a reversal and parallelism in ecological requirements in both clades. Because of these results, we restrict the subfamily Chondrininae to the clade with Chondrina , Abida and Rupestrella , and introduce the Granariinae for the sister-clade with Granaria , Granopupa and Solatopupa .

It is hypothesized that the plesiomorphic bauplan of the apertural teeth in the shells, with the palatalis inferior as the most prominent palatal tooth, is still present in both the Granaria species and Granopupa granum (see Gittenberger 1973: 26). In Abida there is a modification, implying that the two main palatals are equally prominent. In Solatopupa , Chondrina and Rupestrella species with reduced apertural teeth occur. This parallel reduction is restricted to species occurring on large limestone cliffs. It is likely that in this habitat there is an absence of selection in favour of a complete set of apertural teeth.