TRANSITION TO TAIL-POWERED SWIMMING IN THE FIRST FULLY AQUATIC WHALES OF EOCENE TETHYS (EGYPT)

始新世特提斯海第一批完全水生鲸鱼向尾部动力游泳的转变（埃及）

• 批准号: 0920972
• 负责人: Philip Gingerich
• 金额: $ 26.5万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0920972&HistoricalAwards=false
• 关键词: TRANSITION; TAIL; POWERED; SWIMMING; FIRST

Transition to Tail-Powered Swimming in the First Fully Aquatic Whales of Eocene Tethys (Egypt) P. D. Gingerich, University of Michigan This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Whales are mammals that evolved from land to sea during the Eocene epoch of geological time. The transition was made by Archaeoceti or archaic whales that are ancestral to modern Neoceti (Mysticeti or baleen whales and Odontoceti or toothed whales). Four stages of the transition are known from complete or virtually-complete skeletons: I, Eocene artiodactyl land mammals; II, the protocetid archaeocetes Rodhocetus and Maiacetus; III, the basilosaurid archaeocetes Basilosaurus and Dorudon; and IV, modern whales, which first appeared in the latest Eocene or Oligocene. Stage II archaeocetes were semiaquatic, foot-powered swimmers that fed in the sea but still gave birth on land. Stage III archaeocetes were fully aquatic, tail-powered swimmers that were the first to give birth at sea. The two stages differ morphologically in many skeletal characteristics, and the temporal gap between them is on the order of 10 million years (spanning the middle Lutetian through Bartonian ages of the middle Eocene). Skeletons of new morphological and temporal intermediates are required to understand the transition from semiaquatic to fully aquatic whales. Field work carried out from 2005 through 2008 in collaboration with the Egyptian Mineral Resources Authority and the Egyptian Environmental Affairs Agency demonstrated that it is possible to collect well-preserved and exceptionally-complete skeletons of archaeocete whales from middle Lutetian through Bartonian glauconites (greensands) of the ancient Tethys Sea that are spectacularly exposed in the Western Desert of Egypt. Field research proposed here includes three annual two-month expeditions in Egypt, with the objectives being the discovery and analysis of new fossil whale material that fill gaps in early whale evolution. Such new evidence is essential for advancing knowledge of macroevolution across adaptive zones (in this case the transition from land to sea). Broader impacts of this project include enhancement of infrastructure for research and education through discovery of new skeletons representing early stages of whale evolution and training a postdoctoral fellow.

始新世特提斯岛第一批完全水生鲸鱼向尾动力游泳的过渡（埃及） P. D. Gingerich，密歇根大学 该奖项由 2009 年美国复苏和再投资法案（公法 111-5）资助。 鲸鱼是在始新世地质时期从陆地进化到海洋的哺乳动物。 这种转变是由古鲸类或古代鲸鱼完成的，它们是现代新鲸类的祖先（须鲸和齿鲸）。 从完整或几乎完整的骨骼中已知过渡的四个阶段：I，始新世偶蹄类陆地哺乳动物； II，原鲸纲古鲸Rodhocetus和Maiacetus； III、龙王鲸科古生物龙王鲸和多鲁顿； IV，现代鲸鱼，最早出现在始新世或渐新世晚期。 第二阶段的古生物是半水生的、以脚为动力的游泳者，它们在海中进食，但仍在陆地上产卵。 第三阶段的古生物是完全水生的、以尾部为动力的游泳者，它们是第一批在海上分娩的动物。 这两个阶段在许多骨骼特征上存在形态上的差异，并且它们之间的时间间隔约为1000万年（跨越中卢特阶到中始新世的巴托阶时代）。 需要新的形态和时间中间体的骨骼来了解鲸鱼从半水生到完全水生的转变。 2005 年至 2008 年与埃及矿产资源局和埃及环境事务局合作开展的实地工作表明，可以从中卢特海到古特提斯海的巴顿海绿砂岩（裸露在埃及西部沙漠中）收集保存完好且异常完整的古鲸骨骼。 这里提出的实地研究包括每年在埃及进行三次为期两个月的探险，目的是发现和分析新的鲸鱼化石材料，以填补早期鲸鱼进化的空白。 这些新证据对于推进跨适应区（在本例中是从陆地到海洋的过渡）宏观进化的了解至关重要。 该项目的更广泛影响包括通过发现代表鲸鱼进化早期阶段的新骨骼和培训博士后来加强研究和教育基础设施。