The Genus Pterocorys (Radiolaria) from the Tropical Late Neogene of the Indian and Pacific Oceans

Abstract

An extensive study has been made of the radiolarian genus Pterocorys Haeckel in Neogene (< 8 Ma) sediments from the tropical Indian and Pacific Oceans. The detailed morphologies of eight species are described along with their geographic and stratigraphic ranges. Morphometric analysis has suggested certain phylogenetic lineages which are described in detail. Since th merous transitional forms, and since several species are apparently delicate and, therefore, rare, only 2 stratigraphically useful and easily recognizable Neogene datum levels (F.A.D. of P. hertwigii and L.A.D. of P. campanula, both between 0.6 and 1.1 Ma) based on Pterocorys can be identified and paleomagnetically dated. Stratigraphic events associated with the genus Pterocorys and their absolute ages are presented in tabular form.