| Summary: | Session 28: Exceptional Records: Evolution and ecology of microfossils High-resolution records of microfossil assemblages from deep-sea sediment cores covering the last 20,000 years in the North Atlantic Ocean were investigated to understand biodiversity dynamics over decadal–centennial timescales. The results show pervasive control of deep-sea benthic species diversity by rapidly changing climate. Species diversity rapidly increased during abrupt stadial events during the last deglacial and the Holocene interglacial periods. These included the well-known Heinrich 1, the Younger Dryas, and the 8.2 ka events when the strength of Atlantic Meridional Overturning Circulation (AMOC) decreased. In addition, there is evidence for quasi-cyclic changes in biodiversity at a 1500-year periodicity. Statistical analyses revealed that AMOC-driven bottom-water temperature variability is a primary influence on deep-sea biodiversity. Our results based on the exceptionally highly resolved fossil records highlight possible pervasive, synchronous, and sudden ecosystem response to humaninduced climate and ocean-circulation changes in this century.
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