Collaborative Research: Integrated Study of an Exceptional Avifauna from the Eocene Green River Formation: New Data on Avian Evolution and Taphonomy

合作研究：始新世绿河地层中一种特殊鸟类的综合研究：鸟类进化和埋藏学的新数据

• 批准号: 0719758
• 负责人: Julia Clarke
• 金额: $ 15万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0719758&HistoricalAwards=false
• 关键词: Collaborative; Research; Integrated; Study; Exceptional

The pattern and timing of the emergence of all living birds remain some of the most contentious questions in vertebrate systematics. Avian fossils are increasingly sought as calibration points for molecular divergence dating and used to test macroevolutionary hypotheses. This project will investigate the best-preserved early Paleogene avian assemblage from North America to forward rapidly our understanding of Cenozoic avian evolution and taphonomy. The assemblage comprises a rich sample of exceptionally preserved, but largely uncharacterized, fossils deposited in less than ~2000 years in distinct, mapped, and sedimentologically characterized sub-environments of a single lake. The deposits are tightly dated to 50.2+-1.9 Mya and occur in the Fossil Butte Member in Wyoming. The project is the first to integrate systematic analyses and an investigation of preservational biases that impact fossil evidence from key lake assemblages. The results are essential to gaining: 1) a global perspective on early Paleogene avian biodiversity; 2) an understanding of the timing and paleobiogeographic patterns of the avian radiation; and 3) answers to fundamental questions of how birds and their feathers are preserved in key lacustrine environments. The results will have wider significance in providing a basis for comparison and indication of likely biases in other assemblages of fossil birds preserved in similar settings such as the Early Cretaceous Jehol Group that yields feathered dinosaurs. The only way to discover what categories of taxa may be systematically missing in such deposits is through the approach proposed here: phylogenetic and taphonomic study of one of the most complete 'snap shots' of avian diversity under the best conditions possible. The broader impacts of the project include novel integration of specimen-based teaching of anatomy, systematic methodologies, and taphonomic approaches; postdoctoral, doctoral and undergraduate training; and the promotion of public understanding of evolution and biodiversity via museum exhibits, linked outreach materials, and lectures.

所有现存鸟类出现的模式和时间仍然是脊椎动物系统学中最具争议的问题。鸟类化石越来越多地被寻求作为分子分歧年代测定的校准点，并用于测试宏观进化假设。 该项目将调查北美保存最完好的古近纪早期鸟类组合，以快速推进我们对新生代鸟类进化和埋藏学的理解。该组合包含丰富的化石样本，这些化石保存得非常完好，但基本上没有特征，这些化石在不到 2000 年的时间里沉积在单个湖泊的独特、绘制地图和沉积学特征的亚环境中。这些矿床的年代被严格确定为 50.2+-1.9 Mya，产于怀俄明州的 Fossil Butte 段。该项目是第一个整合系统分析和对影响主要湖泊组合化石证据的保存偏差的调查的项目。这些结果对于获得以下成果至关重要：1）对早期古近纪鸟类生物多样性的全球视角； 2) 了解鸟类辐射的时间和古生物地理模式； 3）回答鸟类及其羽毛如何在关键湖泊环境中保存的基本问题。这些结果将具有更广泛的意义，为比较和指示类似环境中保存的其他化石鸟类组合（例如产生有羽毛恐龙的早白垩世热河群）可能存在的偏差提供基础。发现此类沉积物中可能系统性缺失哪些类群的唯一方法是通过此处提出的方法：在尽可能最好的条件下对鸟类多样性最完整的“快照”之一进行系统发育和埋藏学研究。该项目更广泛的影响包括基于标本的解剖学教学、系统方法论和埋藏学方法的新颖整合；博士后、博士生和本科生培训；通过博物馆展览、相关宣传材料和讲座促进公众对进化论和生物多样性的理解。