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

俄勒冈州始新世的克拉诺植物群拥有大量保存完好的水果、种子、叶子和其他植物器官，为北半球热带和亚热带始新世植物群之间的联系提供了重要的联系。在北美第三纪，果实和种子植物群的多样性和保存质量是无与伦比的，这为与英国和欧洲的早第三纪和中第三纪进行比较提供了一个很好的基础，在英国和欧洲，果实和种子沉积物比北美更丰富，研究也更深入。同样多样的克拉诺叶组合便于与其他美洲和亚洲早第三纪植物区系进行比较。资金将支持克拉诺湖组合的继续实地工作和分析。最近获得的许多克拉诺花区的辐射测年数据增加了这项工作对北半球其他地区生物地层对比的价值，以及对太平洋西北地区植物进化和古气候变化的年代学进行微调的价值。

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.