BIOSTRATIGRAPHY, PROVINCIALISM AND EVOLUTION OF EUROPEAN EARLY JURASSIC (PLIENSBACHIAN TO EARLY TOARCIAN) DINOFLAGELLATE CYSTS

Abstract

Abstract New and previously published dinoflagellate cyst data from the Pliensbachian and early Toarcian of northern and southern Europe have been compared in order to define successions of Boreal and Tethyan bioevents respectively. Significant stratigraphical differences between these two regions indicates that strong provincialism affected dinoflagellates in Europe during the Early Jurassic. This therefore precludes the erection of a pan‐European palynostratigraphy for the Pliensbachian to early Toarcian interval. Early Jurassic dinoflagellate cyst provincialism has been quantitatively assessed using the Koch Index of biotal dispersity and the Simpson Coefficient of biotal similarity. These methods conclusively demonstrate that marked provincialism occurred at this time, and that the Boreal and Tethyan realms represent two distinct phytoprovinces, based on their respective dinoflagellate cyst assemblages. The Boreal Realm was characterised by relatively high diversity and the dominance of Luehndea spino...