Cristataria (Nordsieck, 1977)

Uit De Weerd, Dennis R. & Gittenberger, Edmund, 2005, Towards a monophyletic genus Albinaria (Gastropoda, Pulmonata): the first molecular study into the phylogenetic position of eastern Albinaria species, Zoological Journal of the Linnean Society 143, pp. 531-542 : 540

PROVENANCE OF CRISTATARIA

Our results lend some support to the hypothesis that the Cristataria species ‘came from Balkan stock’ ( Bar, 1977). All genera within Medorini , with the exception of Albinaria and Cristataria , are restricted to southeastern Europe. In fact, Albinaria and Cristataria are the easternmost distributed genera within the subfamily Alopiinae (see Nordsieck, 1979). The combined analysis of the ITS and 12S sequences demonstrates that these two genera are nested separately among south-eastern European taxa, implying that they both descended from an ancestor in this area.

Although the Cristataria species are found on the African plate, in contrast to all other Medorini , which are located on the Eurasian plate (see Robertson, 1998), their relatively easterly distribution cannot be attributed to tectonic events. Such an explanation would be problematic since the south-eastern European landmasses, where the sister group and clades basal to Cristataria occur, have been widely separated from the Levant since at least the early Cretaceous ( Robertson & Dixon, 1984; Dercourt, Ricou & Vrielynck, 1992). This separation predates even the earliest known European fossils of Clausiliidae (see Nordsieck, 2000). Alternatively, it can be hypothesized that the ancestors of Cristataria spread from south-eastern Europe through Asia Minor towards the current generic range. If so, it has to be accepted that they became extinct in Asia Minor, to be replaced there by Albinaria species. This hypothesis implies that the geographical barriers that apparently have separated Albinaria and Cristataria during most of their evolution did not hinder the initial spread of the latter’s ancestors into the genus’ current range. The provenance of Cristataria thus remains enigmatic.