Biomarker 4: reussella szajnochae acme
Found in the Mackerel Formation in the Central North Sea and in the Rowe Formation of the Southern North Sea Basin (Late Campanian, mucronata Zone). The FDO of Tritaxia capitosa occurs at the same horizon as the biomarker in the Central North Sea. Bolivinoides decoratus accompanies the biomarker in the Southern and Central North Sea. Planktonic and calcareous benthonic species are commom and diverse.
Correlation: This biomarker can be placed at the top of BGS foraminiferal Biozone 23 (Wilkinson, 2000).