The global synchroneity of the Pseudoemiliania lacunosa extinction and the first appearance of Emiliania huxleyi is established by correlation with the oxygen isotope record in seven cores underlying tropical, subtropical, transitional, and subpolar waters. The P. lacunosa extinction is dated at 458,000 B.P., occurring consistently in the middle of oxygen isotope stage 12, whereas the first appearance of E. huxleyi has an age of 268,000 B.P., occurring consistently late in oxygen isotope stage 8. A third coccolith event, the reversal in dominance between Gephyrocapsa caribbeanica and E. huxleyi, is time-transgressive. In tropical and subtropical waters, it correlates with oxygen isotope stages 5b and 5a, approximately 85,000 B.P.; in transitional waters, it correlates with oxygen isotope stage 4, approximately 73,000 B.P.