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