Ilona Valley revisited - A rich early Miocene gastropod fauna from the North Hungarian Basin.

A new mollusc material from the Ilona Valley Section (Mátra Mts, Hungary) is investigated. Strata of the section represent the Ilonavölgy Member of the Pétervására Sandstone Formation. Based on geochemical data and mollusc biostratigraphy these deposits appear to be early Ottnangian in age. The mollusc fauna displays much higher diversity than was recognized in earlier studies from the locality in question and from other Ottnangian sites in the Paratethys. The rich material verifies the extended stratigraphic and palaeogeographic ranges of numerous taxa, and allows of designating 12 new gastropod species: Clanculus s. l. gulyasi n. sp., Gibbula kralli n. sp., Calliostoma nandori n. sp., Ormastralium erazmusi n. sp., Sconsia landaui n. sp., Cirsotrema kokayi n. sp., Ocinebrina deaki n. sp., Calagrassor mathiasi n. sp., Clavatula s. l. barnabasi n. sp., Clavatula s. l. istvani n. sp., Dentimargo barnai n. sp., Solatisonax pozsgayae n. sp. With 106 figures and 1 table. [ABSTRACT FROM AUTHOR]