BGS Zone 8 (=upper UKB8 and basal UKB9 of Hart et al., 1989)

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Base: Inception of Whiteinella archaeocretacea, Dicarinella imbricata, Heterohelix globosus, Marginotruncana marginata, together with the extinction of Rotalipora cushmani.

Top: Inception of Valvulineria lenticularis and Praeglobotruncana helvetica.

Biomarkers:

  • Gavelinella ammonoides appears near the top of the zone and Arenobulimina preslii becomes more consistently present (in the upper part of the N. juddi macrofaunal zone).
  • Praeglobotruncana stephani disappears from the record at the top of Bed 5 of the Plenus Marls.
  • Gavelinella reussi becomes extinct at the top of Bed 7 of the Plenus Marls.

Macrofaunal correlation: upper M. geslinianum Zone to upper N. juddi Zone

Age: Late Cenomanian