Morphology, biometry and taxonomy of the lowermost Danian planktonic foraminifera: Palaeoglobigerina n. gen.

Abstract

The lowermost Danian contains oligotaxic planktic foraminiferal assemblages with species of small size (< 150 μm) and very simple morphology, derived from an evolutionary radiation occurred after the Cretaceous/Paleogene (K/Pg) mass extinction event. The taxonomic classification of this foraminiferal group has been revised, after performing biometric and morphological analysis in order to delimit the species. This study and the biostratigraphic distribution of the species are based on material and previous high resolution samplings from some of the most continuous K/Pg sections worldwide. Palaeoglobigerina n. gen. is proposed to include the small trochospiral globigerinid species, with smooth wall-texture, 3-4 chambers in the last spire whorl, occurring in the Guembelitria cretacea and Parvularugoglobigerina eugubina Zones (lowermost Danian). Twenty two species are recognized, described and illustrated: five of Guembelitria, two of Hedbergella, two of Woodringina, two of Chiloguembelina, five of Palaeoglobigerina n. gen., and six of Parvularugoglobigerina