| 英文摘要: | Flowering plants first appeared approximately 140 million years ago, during the age of dinosaurs. Flowering plants rapidly diversified and spread around the globe and evolved a variety of life forms that added to the ecological complexity of forests. This project investigates a crucial interval of this transition, ~75 million years ago, by studying a series of exceptionally preserved fossil floras from southern New Mexico, which existed under a wet tropical paleoclimate. These studies will provide important insights into forest evolution in tropical climates, the timing and patterns of ecological expansion of flowering plants, the habitats of dinosaurs and early mammals, and the history of vegetation for the western interior of North America. Most of these plant fossils collected this research represent species new to science and can provide important historical records for living lineages. The project provides training for students from diverse backgrounds. It also has several major initiatives for education and public outreach, including the development, testing, and dissemination of lesson plans for science teachers about the rise of flowering plants and modern forests.
This project will use extensive paleontological field studies, fossil collections, and new quantitative techniques to generate extensive reconstructions of late Campanian forests from fossilized leaves, wood, seeds and fruits. By using newly developed sampling and analytical techniques, these studies will generate reconstructions of the diversity and ecological structure of the paleo forests. The fossil floras are from the Jose Creek Member of the McRae Formation in south-central New Mexico, which was located >200 km inland of the Western Interior Seaway. The diversity and community structure of the fossil forests will be reconstructed using spatial distributions of plant species across the landscape, while the functional ecology of the plants will be reconstructed by measuring traits of leaves, wood, and seeds/fruits that are reflective of life form, physiology, growth rate, and reproductive strategy. This information, when combined with analyses of climatically similar Cretaceous, Cenozoic, and extant floras, will be used to test hypotheses about: 1) the community structure and roles of major clades in Campanian floras; 2) the functional ecology of Cretaceous angiosperms; and 3) how the ecological structure of forests has changed through time in warm-wet climates. The functional trait-based approach used will link extant and paleo-ecology, and have broad applicability to understanding ecological radiations and community turnover following key evolutionary innovations. |