'Organic nannofossils': a new type of palynomorph from the Palaeogene of the North Sea

Organic microfossils of regular dodecahedral shape are found in the Palaeog ene (Lower Oligocene) of the central and northern parts of the Norwegian No rth Sea. The shape and structure of these fossils are very similar to cocco spheres of the calcareous nannoplankton genus Braarudosphaera. The individu al pentagonal plates show the same morphological features as replicas of th e inner surface of pentaliths forming calcareous coccospheres. It is the fi rst evidence that a representative of calcareous nannoplankton (Haptophyta, Coccolithophorales) is found to produce acid-resistant organic microfossil s. The organic remains might have been produced by an undescribed species o f the genus Braarudosphaera or represent an unknown stage in the life cycle of species which normally produce calcareous plates.