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

在始新世特提斯(埃及)的第一头完全水生鲸鱼(埃及)P.D.Gingerich中过渡到尾巴动力游泳，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。这种转变是由古鲸或现代新鲸的祖先(须鲸或须鲸和齿鲸或有齿鲸)完成的。从完整或几乎完整的骨骼中已知四个过渡阶段：I，始新世偶龙类陆地哺乳动物；II，原生古生物Rodhoctus和Maiacus；III，担龙类古生物Basilosaurus和Dorudon；以及IV，最早出现在始新世或渐新世的现代鲸鱼。第二阶段的考古学家是半水生的，以脚为动力的游泳者，它们在海洋中觅食，但仍然在陆地上分娩。第三阶段的考古者是完全水生的、用尾巴供电的游泳者，他们是第一个在海上分娩的人。这两个阶段在许多骨骼特征上存在形态上的差异，它们之间的时间间隔约为1000万年(横跨中始新世的吕特中期到巴顿时代)。需要新的形态和时间中间体的骨骼来理解从半水栖鲸鱼到完全水生鲸鱼的转变。2005年至2008年与埃及矿产资源管理局和埃及环境局合作进行的实地工作表明，有可能从古特提斯海的鲁特海中部到Bartonian海绿石(绿地)收集保存完好和异常完整的考古鲸鱼骨架，这些遗骸惊人地暴露在埃及西部沙漠中。这里提出的实地研究包括在埃及进行为期两个月的三次年度探险，目的是发现和分析填补鲸鱼早期进化空白的新的鲸鱼化石材料。这种新的证据对于促进跨适应带(在这种情况下是从陆地向海洋的过渡)的宏观进化的知识至关重要。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架来加强研究和教育的基础设施，以及培训博士后研究员。

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.