On the status and occurrence of the foraminiferal genera Nubecularia and Sinzowella in the late Middle Miocene of the Paratethys Sea

Abstract

“Nubecularia bioherms” represent unique foraminifera dominated buildups which are restricted to the late Middle Miocene (late Serravallian) of the Paratethys. They occur in the Central Paratethys in the late Sarmatian and in the Eastern Paratethys in the Volhynian–Bessarabian, both regional stages of the respective Paratethyan areas. The generic assignment of the main constituent of the bioherms changed in time from Spirorbis to Nubecularia and Sinzowella. No clear diff erential diagnosis has been provided for the establishment of the genus Sinzowella by Cushman (1933) and the diff erence between both porcelaneous taxa was reported to be the agglutination of foreign particles in Nubecularia (Loeblich and Tappan 1964, 1987). Since in studied Central Paratethyan material agglutinated particles occur frequently in the test wall a separation of Sinzowella from Nubecularia is not justifi ed based on this character and Sinzowella is considered synonymous with Nubecularia. At the species level the situation is even more confusing since a variety of species (nodulus, novorossica, caespitosa), subspecies or/and “types” (e.g., nodulus, solitaria, deformis) have been described. All these taxa are considered to be subjective junior synonyms of Nubecularia nodulus which is the only Nubecularia species in the Central Paratethys since all described morphotypes co-occur even in a single rock thin section.