A typical monospecific association of calcareous nannoplankton has been observed in a number of boreholes from Pannonian sediments of Vojvodina (North Serbia). It was a new genus, Praenoelaerhabdus, that most resembled Dictyococcites Black 1967 and Noelaerhabdus Jerkovic 1970. The Noelaerhabdus is supposed to have descended from the Praenoelaerhabdus n. gen. The need is emphasized for a detailed explanation of the causes of endemicity among calcareous nannoplankton in the specific refreshened area of the Pannonian Basin.