Systematic Affinities and Biogeographic Relationships of Fossil Floras from the Eocene Clarno Formation of Oregon

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The Eocene Clarno flora of Oregon with its large assemblanges of exquisitely preserved fruits and seeds, leaves and other plant organs, provides an important link in correlating tropical to subtropical Eocene floras across the Northern Hemisphere. The fruit and seed flora is unparalleled in the Tertiary of North America for diversity and quality of preservation, and provides an excellent basis for comparison with the early and mid-Tertiary of England and Europe, where fruit and seed deposits are more abundant and more thoroughly studied than in North America. The similarly diverse Clarno leaf assemblages facilitate comparison with other American and Asian early Tertiary floras. Funding will support continued field work and analyses of Clarno lacustrine assemblages. Recently acquired radiometeric dates for many of the Clarno floral localities increase the value of this work for biostratigraphic correlation of other regions of the Northern Hemisphere, and for fine-tuning the chronology of floral evolution and paleoclimatic change in the Pacific Northwest.