Distribution of calcareous nannofossils in Cretaceous to Paleogene sediments of ODP Hole 208-1262C at Walvis Ridge, South Atlantic Ocean (Appendix A)

High resolution calcareous nannofossil quantitative analyses were carried out across the K/P boundary, and provided a remarkable record of the abrupt and catastrophic extinction. The calcareous nannofossil assemblages are abundant and well preserved allowing to obtain a precise bioevent sequence and to document in detail the survivors and victims and the subsequent recovery across the K/P boundary.Late Maastrichtian diversity and absolute abundance is high and no decrease towards the boundary has been observed.

The relative abundance of Cretaceous species does not suffer important changes during the latest Maastrichtian. However, the increase in abundance of cool-water taxa, paralleled with a decrease of warm water taxa in the uppermost 2 cm of the Maastrichtian, revealed a pulse of surface water cooling.The K/P boundary is marked by an important decrease in calcareous nannofossil absolute abundance, the increase of Cretaceous-persistent species such as Cyclagelosphaera reinhardtii together with the dinoflagellate cysts of Thoracosphaera operculata and the appearance of the new-Paleocene taxa Cyclagelosphaera alta and Biantholithus sparsus.