Analyses of molecular phylogeny have revealed that phenotypically identified taxa do not reflect phylogenetic relationships. Such taxa often are not evolutionary significant and are misleading in describing and evaluating biological diversity. Herein, we investigated the molecular phylogeny of the East Asian bradybaenid land snail genera Aegista, Landouria, Trishoplita, and Pseudobuliminus to test whether morphology and current taxonomy reflect phylogenetic relationships. Our results document extensive parallel evolution and substantial incongruence between taxonomy and molecular phylogeny. Species with an elongated turret shell evolved independently five times, and hair-like ornamentation of the shell was independently gained or lost in a number of lineages. Although genital anatomy reveals phylogenetic conservatism to some extent, love dart and dart-related organs were lost independently at least three times in these genera. Accordingly, classification of these genera based on morphological traits did not reflect phylogenetic relationships, and, overall, these genera except for a few species should be tentatively assigned to a single genus as Aegista. The present findings suggest that radical revision is required for the taxonomy of bradybaenid land snails.
- Land snail