EAGER: Neogene fruits and seeds from the Gray Fossil Site, Tennessee: Using multiple imaging techniques to clarify an obscure interval in the history of Appalachian vegetation

该项目将分析田纳西州东部格雷化石遗址的水果和种子化石。该遗址是2000年发现的一个古老的天坑，目前正在进行挖掘，发现了大量保存完好的陆地动植物化石，生活在大约700万到450万年前。阿巴拉契亚地区这一时期的植被意义重大，因为它早于更新世环境变化造成的广泛生态干扰，但人们对其生物多样性还没有很好的了解。因此，灰色化石遗址提供了一个独特的机会来阐明阿巴拉契亚地区的生态系统在最近的地质历史中发生了怎样的变化。研究人员将从该地点识别出化石水果和种子的物种，并描述那些科学上新发现的物种。然后，他们将把在该遗址发现的植物化石物种的多样性与世界各地其他古代和现代植物的多样性进行比较。这种比较可能提供关于生物多样性、灭绝的速度以及从局部到全球范围内植物物种的地理范围转移的变革性见解。研究人员将在灰色化石遗址和博物馆培训本科生，并通过制作化石植物群的数字游客指南来吸引公众。研究成果将被广泛传播，并将包括对美国国家科学基金会资助的开放获取的古代生命数字地图集的贡献。该项目将为灰色化石遗址创建第一个全面的碳素植物群。研究人员将使用光学显微镜、扫描电子显微镜和微型计算机断层扫描相结合的方法来分析之前挖掘出的水果和种子化石。这些方法提供了互补的数据，表征了表面形态和内部解剖细节，而不需要破坏性解剖。如果可行，项目人员将使用结构特征和系统发育分析来确定化石的系统亲缘关系。然后，他们将根据化石的分类来评估碳水化合物区系的生物地理关系。这些数据将检验一种假设，即果子植物区系将与欧亚大陆和北美的古代和现代植物群有最大的相似性。该项目的成果将包括对北美中新世和上新世生态系统的更好了解，阿巴拉契亚植物区系的历史生物地理，以及灰色化石遗址Carpoflora的内部解剖保存状况。该项目将改善美国化石收藏的管理，并加强美国机构之间的研究合作。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project will analyze the fossilized fruits and seeds from the Gray Fossil Site located in eastern Tennessee. Ongoing excavation of the site, an ancient sinkhole deposit discovered in 2000, has yielded numerous, well-preserved fossils of terrestrial plants and animals that lived approximately seven to four-and-a-half million years ago. The vegetation of this time period in the Appalachian region is significant because it predates the widespread ecological disturbance caused by Pleistocene-age environmental changes, yet its biodiversity is not well understood. Consequently, the Gray Fossil Site presents a unique opportunity to clarify how ecosystems of the Appalachian region have changed over recent geological history. Researchers will identify species of fossil fruits and seeds from the site and will describe those new to science. They will then compare the diversity of fossil plant species found at the site to that of other ancient and modern plants world-wide. The comparison may provide transformative insights regarding the pace of biological diversification, extinction, and geographic range shifts of plant species at a local to global scale. Researchers will train undergraduate students and engage the public at the Gray Fossil Site and Museum by producing a digital visitor's guide to the fossil flora. Research results will be disseminated widely and will include contributions to the NSF-funded, open access Digital Atlas of Ancient Life.This project will create the first comprehensive carpoflora for the Gray Fossil Site. Researchers will analyze previously excavated fruit and seed fossils using a combination of light microscopy, scanning electron microscopy and micro-computed tomography. These methods supply complementary data that characterize both surface morphological and internal anatomical details without the need for destructive dissection. Project personnel will determine the systematic affinities of the fossils using structural characteristics and phylogenetic analyses, where feasible. They will then assess the biogeographic relationships of the carpoflora based on the taxonomy of the fossils. These data will test the hypothesis that the carpoflora will share greatest similarities to the ancient and modern floras of Eurasia and North America. Outcomes of this project will include an improved understanding of Miocene and Pliocene ecosystems of North America, the historical biogeography of the Appalachian flora, and the state of internal anatomical preservation of the Gray Fossil Site carpoflora. The project will improve the curation of US fossil collections and strengthen research collaborations among US institutions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.