Gonioteuthis westfalica westfalica Zone

Base: The base of the zone is marked by the first appearance of the index species, but in England this is slightly higher relative to the European standard succession (Christensen, 1991). However, in England, the top of the range of the index of the underlying zone (G. westfalica praewestfalica) is coincident with the base of the current zone as defined in the European standard succession (Christensen, 1991).

Range of index species: In England, the index ranges from within the lower part of the zone to the top of the zone (Christensen, 1991). In the European standard succession, the range of the index is co-extensive with the zone (Christensen, 1991).

Biostratigraphical correlation: The zone equates with most of the higher part of the M. coranguinum Zone of the standard macrofossil zonal scheme for the UK Chalk Group (Christensen, 1991).

Lithostratigraphical correlation: The zone can be inferred to equate with an interval in the higher part of the Seaford Chalk Formation of southern England.

Age: Santonian (Christensen, 1991).