Single-species dinoflagellate cyst carbon isotope ecology across the Paleocene-Eocene Thermal Maximum

摘要

We present the first ever species-specific fossil dinoflagellate cyst stable carbon isotope (delta C-13) records, from the Bass River Paleocene-Eocene Thermal Maximum (PETM) section in New Jersey (USA), established using a novel coupled laser ablation-isotope ratio mass spectrometer setup. Correspondence with carbonate delta C-13 records across the characteristic negative carbon isotope excursion indicates that the delta C-13 of dissolved inorganic carbon exerts a major control on dinocyst delta C-13. Pronounced and consistent differences between species, however, reflect different habitats or life cycle processes and different response to pCO(2). Decreased interspecimen variability during the PETM in a species that also drops in abundance suggests a more limited niche, either in time (seasonal) or space. This opens a new approach for ecological and evolutionary reconstructions based on organic microfossils.