A 100 Million Year Composite Pollen Record From New Zealand Shows Maximum Angiosperm Abundance Delayed Until Eocene

Although significant angiosperm diversification occurred during the Cretaceous, the timing of subsequent expansion of flowering plants across austral landscapes is poorly understood due to a lack of continuous records. Our new 100 million year composite pollen record from New Zealand shows a striking temporal separation between diversification and ecological dominance in this group. While Cretaceous diversification was closely followed by an increase in angiosperm frequency, maximum frequency did not occur for another 40 million years, during the Eocene. The two most consistent intervals of floral change over the 100 Myr record occur within the middle Eocene and the middle Miocene. Notable floral changes also occur around the Cretaceous-Paleogene, Paleocene-Eocene, and Pliocene-Pleistocene transitions. These major changes occur in the context of the northward drift of Zealandia across the Antarctic circle, global warming in the early Paleogene, and middle Miocene, and onset of Southern Ocean circumpolar circulation and cooling in the late Paleogene.