Jurassic gastropods from Sicily; new data to the classification of Ataphridae (Trochoidea)

Members of Ataphridae became a progressive group in one of the two types of Tethyan faunas. Some of the new forms, which evolved from ataphrid ancestors, can be classified within the family, whilst others show a transitional morphology towards the turbinid subfamily Colloniinae. Other finds sug-gest a close relationship between Ataphridae and Crossostomatidae. Detailed palaeontological exploration of poorly known palaeobiogeographical regions frequently results in new evidence leading to modifications in the syste-matics of certain fossil groups. That is the case with the long known Jurassic 'Mediter-ranean Province ' of the Tethyan Realm, which was established practically on the basis of ammonite faunal data (Neumayr, 1872). Almost each new locality contains un-known gastropod taxa and many of them cannot be accommodated within the ex-isting systematical framework. The Early to Middle Liassic Mediterranean gastropods are relatively well known but the Late Liassic and younger record is scarce. The pre-Toarcian faunas not only show a strong provincialism in relation to those of the shelves and epicontinental seas of stable Europe but also a palaeobiogeographical inhomogenity of the 'Medi