Diatom record of the Paleocene-Eocene Thermal Maximum in marine paleobasins of Central Russia, Transuralia and adjacent regions

A compilation of published and new diatom data from 14 stratigraphic sections of Central Russia, Transuralia, and adjacent regions across the Paleocene-Eocene Thermal Maximum (PETM) is presented. It is shown that in response to the rapid warming during the PETM, diatoms show evolutionary patterns displayed also by other microplankton groups, in particular dinocysts and nannofossils. Species and genera evolution becomes intensified, with the appearance of short-lived species of unusual morphologies and invasion of thermophilic migrants from open ocean tropical regions to the intracontinental basins of North Eurasia. Moreover, diatom assemblages are characterized by reappearance of Late Cretaceous and Early Paleocene relics that subsequently went extinct in the Early Eocene.