BGS Zone 9 (=modified UKB9 of Hart et al., 1989)

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Base: Inception of Valvulineria lenticularis and Praeglobotruncana helvetica.

Top: Inception of Globorotalites michelinianus and extinction of Lingulogavelinella globosa.

Biomarkers:

  • Whiteinella aprica appears in the early Mytiloides spp macrofaunal zone.
  • The extinction of Dicarinella hagni and D. algeriana together with the inception of Marginotruncana sigali in the ‘mid’ Mytiloides spp macrofaunal zone.
  • Gavelinella tourainensis generally temporarily disappears from the record at the top of the zone (Lazarus Effect).

Macrofaunal correlation: uppermost N. juddi Zone to upper Mytiloides spp. Zone.

Age: Latest Cenomanian & Early Turonian