Morphological and molecular analysis of the status and relationships of Oxychilus paulucciae (De Stefani, 1883)(Gastropoda: Pulmonata: Zonitidae)

Morphological data shows that O. paulucciae (De Stefani, 1883) belongs to Oxychilus (s. str.), sensu Giusti & Manganelli (1999), and is distinguished from sympatric, similarly shelled species, such as O. draparnaudi (Beck, 1837) and O. meridionalis (Paulucci, 1881), by its larger shell (diameter: 13.9-17.4 mm), smaller umbilicus (about 1/8 of shell diameter), narrow mid-penial region, internal ornamentation of proximal penis consisting of longitudinal pleats, and a less developed vaginal gland, often forming an incomplete ring around proximal vagina. DNA sequence data, analysing the ITS-1 region in two specimens of O. paulucciae and representatives of several other species occurring in Tuscany, O. draparnaudi, O. majori (Paulucci, 1886), O. meridionalis, O. pilula (Paulucci, 1886) and O. uzielli (Issel, 1873), indicates that O. paulucciae represents a well-differentiated evolutionary lineage and suggests it has close relationships with O. meridionalis and O. uziellii. Finally, analysis of morphological characters and DNA sequencing data demonstrates that Oxychilus lanzai Forcart, 1967, is a junior synonym of O. paulucciae.