BGS Zone 7 (=lower UKB 8 of Hart et al., 1989)
Base: Extinction of Hagenowina advena in the base of the Plenus Marls.
Top: Inception of Dicarinella imbricata, Whiteinella archaeocretacea, Heterohelix globosus, Marginotruncana marginata, together with the extinction of Rotalipora cushmani
Biomarkers:
- Extinction of Rotalipora greenhornensis, Gavelinella cenomanica, Tritaxia macfadyeni, Plectina cenomana at the top of Bed 1 of the Plenus Marls.
- Extinction of Gavelinella baltica and Gavelinella intermedia in Bed 2 of the Plenus Marls. Rotalipora cushmani extinction at the top of Bed 3 of the Plenus Marls.
Macrofaunal correlation: lower to middle M. geslinianum Zone.
Age: Late Cenomanian