BGS Zone 10 (=basal UKB10 of Hart et al., 1989)
Base: Inception of Globorotalites michelinianus and extinction of Lingulogavelinella globosa.
Top: Inception of Marginotruncana pseudolinneiana.
- The Lazarus effect causes a general disappearance of Gavelinella tourainensis at the base of the zone, but the species reappears in the Late Turonian.
- Although a long ranging taxon, the inception of common Labyrinthidoma (= Coskinophragma) is characteristic of the New Pit Chalk Formation (at the level of the New Pit Marls) in south-eastern England (upper part of the foraminiferal zone and middle part of the T. lata macrofaunal zone).
Macrofaunal correlation: upper Mytiloides spp. Zone to middle T. lata Zone
Age: Early Turonian