Plankton and benthic foraminiferal dataset for the study of the Eocene-Oligocene transition

The Eocene–Oligocene transition (EOT) was the crucial turning point when
Earth’s climate shifted to its current cool state. Understanding how life
responded to this “warmhouse-to-icehouse” shift was limited by the absence
of high-resolution fossil data. Here, we use a novel AI algorithm to
construct a 28-myr-long species richness history of foraminifera with
~26,000-year resolution. A significant richness decline occurred during
the EOT, eliminating 74% of species. Planktonic and larger benthic
foraminiferal extinctions are associated with rapid cooling, sea-level
fall, and positive carbon isotopic excursion. However, small benthic
foraminifera in deep oceans experienced a two-phase biocrisis coinciding
with changes in food supply and volcanic activity. These findings reveal
complicated, ecologically differentiated environment-life processes and
the need to reconsider other major bioevents in deep time.