Forresteria (Harleites) petrocoriensis (COQUAND, 1859) from the Upper Turonian Mytiloides scupini Zone of Słupia Nadbrzeżna, Poland

Abstract

Forresteria (Harleites) petrocoriensis (Coquand, 1859) the classic ammonite marker for the base of the Coniacian stage in the Aquitaine Basin, France, is recorded from the Upper Turonian Mytiloides scupini Zone of Słupia Nadbrzeżna, Poland. The position of the upper and lower limits of the petrocoriensis Zone in terms of the standard inoceramid zonation across the Turonian-Coniacian boundary interval remains uncertain, and the proposed base of the Coniacian - the first occurrence of Cremnoceras deformis erectus (Meek, 1877) - lies in the lower part of the range of F. (H.) petrocoriensis. The inoceramid-defined base of the Coniacian cannot be recognised in the environs of Cognac, the type locality of the stage.