On the identity of Clio ricciolii (Calandrelli, 1844) (Gastropoda: Euthecosomata) from the Pliocene of Rome, Italy

The pteropod species Clio ricciolii (Calandrelli, 1844) was originally described from Pliocene deposits of the Monte Vaticano at Rome (Italy). In view of the fact that only the ventral side of the shell was then described and illustrated, and in the absence of type or topotypical material, as well as on account of the subsequent confusion with Clio sinuosa (Bellardi, 1873) in the literature, the present species has remained enigmatic ever since. New topotypical material has recently become available, enabling full description and designation of a neotype. Clio ricciolii is closely related to the similarly Mediterranean C. braidensis (Beliardi, 1873) (Serravallian- Piacenzian), but for the time being these taxa are considered to be separate species.