New insights in the phylogenetic relations within the Orthalicoidea (Gastropoda, Stylommatophora) based on 28S sequence data

New phylogenetic data are presented on the land snail superfamily Orthalicoidea, using sequences of 22 taxa. In general, the results corroborate the findings of previous authors, but provide a better resolution for several groups within this superfamily. Most basal in the phylogeny are Orthalicidae s.str. and Amphibulimidae. The Placostylidae sensu Bouchet et al. (2005) and the African genus Prestonella, the Australian Bothriembryon and the South American Plectostylus form one clade, classified with the Placostylidae. Odontostomidae and Bulimulidae are the remaining wellsupported clades.