Chalk Biozone 15 - Neoeurysphaeridium glabrum
Age: Earliest Maastrichtian.
Macrofaunal correlation: The B. lanceolata Zone.
Definition: The interval between the LAD of Palaeohystrichophora infusorioides and the LAD of Neoeurysphaeridium glabrum.
Comments: Alternative biomarkers for the top of this biozone are the LADS of Eatonicysta hapala, Odontochitina costata, Odontochitina operculata and Turnhosphaera hypoflata (see Kjellström, 1973; Wilson, 1974; Haq et al., 1987; Costa & Davey, 1992; Schiøler & Wilson, 1993; Foucher & Monteil, 1998). The FAD of Triblastula utinensis typically occurs within this biozone (Wilson, 1974; Schiøler & Wilson, 1993).
Lithostratigraphical correlation: The Sidestrand Chalk and the Trimingham Sponge Beds members (East Anglia) and the Mackerel Formation (North Sea).