Morphometrical variability of Helicosphaera ampliaperta (calcareous nannoplankton) in the central Paratethys: biostratigraphic and paleogeographic applications

Abstract

Biometrical variability of the size and shape of the nannoliths and central opennings of the calcareous nannoplankton species Helicosphaera ampliaperta enable to distingiush two morphotypes. First occurrences of these morphotypes in Central Paratethys can be correlated with the paleogeographical events.

Keywords

• calcareous nannoplankton
• Miocene
• Central Paratethys
• biometry
• biostratigraphy
• paleogeography