Paleobiogeographic Distribution of the Early Cretaceous Radiolarian Turbocapsula costata and Its Correlation Potential

Abstract

Abstract. Turbocapsula, having three (or four) segments with a characteristic oval shape and a hemi-closed segmental end, is a radiolarian genus with a high stratigraphic value due to its phyletic evolution in the mid-Cretaceous period. An overview of lithology, depositional setting, associated fossil records, and paleomagnetic data from each locality of Turbocapsula costata (Wu) is summarized. All these data lead to the conclusion that locations of known T. costata-bearing strata are restricted to the low- to mid-latitude Mediterranean and eastern Tethys of the Tethyan realm. The results emphasize that the phyletic evolution of the genus Turbocapsula is significant in correlations within the Tethys. The zonation established by the phyletic evolution of the genus Turbocapsula cannot be utilized for Early Cretaceous zonal correlations beyond the T. costata territory.