The Eocene North Atlantic land bridge:its importance in Tertiary and modern phytogeography of the Northern Hemisphere

from the Cretaceous to the Tertiary marks a time of significant modernization in the history of flowering plants. During this interval, a wide range of extant families and genera first appeared, as recorded in the fossil record of pollen (Muller, 1970 data). This modernization was probably spurred by coevolution with pollinators (Crepet, in press) and dispersal agents (Tiifney, in press) and resulted in a major change in the floristic and vegetational composition of the world's plant communities.