Cenozoic paleoceanography records a sequence of major events that reorganized ocean circulation and climate: Antarctic ice sheet formation at the Eocene-Oligocene boundary (~34 Ma), the emergence of the Panama Isthmus and closing of the Central American Seaway (Pliocene, ~3-4.6 Ma), the Last Glacial Maximum (~20 ka), and the Younger Dryas cold reversal (~12.9-11.7 ka). Arranging these chronologically from oldest to youngest tests knowledge of the timing of these landmark Cenozoic oceanographic-climatic events.