Gonioteuthis westfalica praewestfalica Zone
Base: Defined in the NW European standard zonation by the first occurrence of the index species (Christensen, 1991). In England, the first occurrence of the species is slightly higher than the equivalent level in the European standard (Christensen, 1991).
Range of index species: In the European standard, the range of the index species is co-extensive with the nominate zone, and in England the index ranges from slightly above the base of the zone to the top of the zone (Christensen, 1991).
Biostratigraphical correlation: The zone equates with an interval in the lower 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 the lower to middle part of the Seaford Chalk Formation in southern England.
Age: topmost Coniacian (Christensen, 1991).