UINTACRINUS ANGLICUS RASMUSSEN FROM THE UPPER CRETACEOUS FLAMBOROUGH CHALK FORMATION OF YORKSHIRE - IMPLICATIONS FOR THE POSITION OF THE SANTONIAN-CAMPANIAN BOUNDARY

Calyx plates of the crinoid Uintacrinus anglicus are recorded from the top and bottom of a 5 m interval, 4m above the disappearance of calyx plates of the crinoid Marsupites testudinarius within the Flamborough Chalk Formation at Danes Dyke in North Yorkshire, UK. The U. anglicus Zone, as used here, comprises the interval from the disappearance of M. testudinarius to the disappearance of U. anglicus calyx plates, and therefore includes, but does not comprise, the total range of the ind ex species. Two subzones are recognized in the M. testudinarius Zone; a lower subzone characterized by smooth Marsupites calyx plates and an upper subzone characterized by variably ornamented Marsupites calyx p lates. A provisional study of the belemnite succession indicates that Gonioteuthis granulataquadrata appears in the highest part of the M. t estudinarius Zone. The 1983 Copenhagen symposium on Cretaceous stage b oundaries proposed that the base of the Campanian Stage should be draw n at a level close to the appearance of G. granulataquadrata. Conseque ntly, the extinction of M. testudinarius is used to define the base of the Campanian here and the U. anglicus Zone is placed in the basal Lo wer Campanian. (C) 1995 Academic Press Limited.