Radiolarian magnetobiochronology and faunal turnover across the middle/late Eocene boundary at Ocean Drilling Program Site 1052 in the western North Atlantic Ocean

► We examine the radiolarian assemblage across the middle/late Eocene boundary. ► We calibrate 45 radiolarian bioevents to the magneto- and cyclo-stratigraphy. ► Radiolarian faunal turnover occurred within Chron C17n.3n (37.7 Ma). ► We name the turnover phase, the Middle/Late Eocene Turnover (MLET).