Distefanella Parona, 1901 a radiolitid rudist from Late Cretaceous platform margin in central-eastern Mediterranean Tethys

Parona (1901) proposed the genus Distefanella for some long, slender and thin-shelled radiolitids from San Polo Matese, southern Apennines, Italy, describing three more species: D. bassanii, D. guiscardii and D. douvillei, besides the type species erroneously attributed to D. lumbricalis (d'Orbigny). Parona (1912a) corrected himself proposing D. salmojraghii, after a detailed description of Biradiolites lombricalis (d'Orbigny) was given in Toucas (1909). Nevertheless, the original mistake, together with some misinterpretation of the radial bands and inner shell structures, caused considerable taxonomic confusion, leading to the misfortune of the genus. The study of Parona's types, together with other specimens kept in museums and new material, allowed us to recognise, describe, and illustrate the diagnostic characters of the radiolitid genus Distefanella. The revision of all the species attributed to the genus lead to recognizing numerous junior synonyms of the Turonian-Coniacian D. salmojraghii Parona and D. montagnei Slišković, and also of the Campanian D. radoicicae Pejović, the three species accepted herein. The genus is almost exclusively found in shelf margin context with high sediment accumulation rate of the central and eastern Mediterranean Tethys.