Descrizione di Turbonilla flaianoi n. sp. per il Mare Adriatico

A re-examination of an uncommon pyramidellid found in the Adriatic Sea, in the Pescara area, previously ascribed to Chrysallida fischeri (Hornung & Mermod, 1925) (Mazziotti et al., 2002), was made necessary after some specialists expressed doubts about the determination. After a comparison with the type material of C. fischeri and other similar species, the Authors concluded that these specimens belong to a new species, Turbonilla flaianoi n. sp., here described. The new species is placed in the genus Turbonilla sensu latu due to the lack of columellar teeth or plica and the presence of a protoconch with an exposed nucleus. T. flaianoi n. sp., is characterised by a cylindrical profile, a sculpture composed by strong axial ribs and well developed spiral cords (10 on the penultimate whorl) in the interspaces. No other Mediterranean species has a similar sculpture. The new species has been therefore compared with the unique other species known to have a similar sculpture pattern, all living in the Indo-Pacific: T. microscopica Laseron, 1959, T. (Pyrgostelis) emiliae Melvill, 1896 and Pyrgulina sykesi Dautzenberg & Fischer, 1907. The type series of T. emiliae is composed by five specimens, differing among them for protoconch shape and inclination. T. flaianoi n. sp. was compared with the specimen of T. emiliae more close to Melvill’s original description, from which it differs for a more cylindrical profile, a last whorl less high (40% against 53%), axial ribs narrower than interspaces extended over the base and wider aperture. T. flaianoi n. sp. differs from T. microscopica by having a more pupoid shell profile and a proportionally lower body-whorl and aperture, a more depressed apex and nucleus less protuding a lower number of axial ribs, a very slight subsutural depression and for lacking rib grooves at the sutures. T. flaianoi n. sp. differs from P. sykesi by having more axial ribs, a proportionally lower body-whorl, a non-arched columella and a wider aperture.