In the largest global cooling event of the Cenozoic Era, between 33.8 and 33.5 Myr ago,
warm, high-CO2 conditions gave way to the variable 'icehouse'climates that prevail today.
Despite intense study, the history of cooling versus ice-sheet growth and sea-level fall
reconstructed from oxygen isotope values in marine sediments at the transition has not been
resolved. Here, we analyse oxygen isotopes and Mg/Ca ratios of benthic foraminifera, and
integrate the results with the stratigraphic record of sea-level change across the Eocene …