Abstract
Trochulus oreinos oreinos and T. oreinos scheerpeltzi are two land snail taxa endemic to the Northeastern Austrian Alps, which have been regarded as subspecies of the highly variable, widespread land snail T. hispidus. We analysed these three taxa morphologically and genetically to evaluate whether a delimitation between them is possible and, if so, to resolve their phylogenetic relationships. Shell morphological results revealed high similarity between the two T. oreinos taxa, and that they are clearly separated from T. hispidus. Additionally, the T. oreinos subspecies concur with respect to their habitat preferences, as they are both restricted to rocky high alpine areas, whereas the local form of T. hispidus is distributed over a wider altitudinal range in moist areas and scrubby perennial herb vegetation near water bodies. While the morphological and ecological results allow clear differentiation between T. hispidus and T. oreinos only, analyses of the mitochondrial cytochrome c oxidase subunit I and 16S rRNA genes revealed high sequence divergences between all three taxa, which indicates that they represent old lineages. The two T. oreinos taxa appear as distantly related sister groups, well separated from T. hispidus. Whether T. o. oreinos and T. o. scheerpeltzi should be considered as species cannot be decided at the current state of knowledge.