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

俄勒冈州始新世克拉诺植物群及其大量保存完好的果实和种子、树叶和其他植物器官，为整个北半球热带和亚热带始新世植物群的关联提供了重要的联系。果实和种子植物群在北美第三纪的多样性和保存质量方面是无与伦比的，为与英格兰和欧洲的早第三纪和中第三纪进行比较提供了良好的基础，后者的果实和种子储量比北美更丰富，研究也更深入。克拉诺叶组合具有相似的多样性，便于与其他美洲和亚洲早第三纪植物群进行比较。资金将用于支持继续开展实地工作和分析克拉诺湖相组合。最近获得的克拉诺许多植物区系的放射性测量日期增加了这项工作的价值，有助于北半球其他地区的生物地层对比，以及微调太平洋西北地区植物演化和古气候变化的年表。

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.