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

始新世特提斯（埃及）第一个完全水生的鲸鱼向尾部动力游泳的过渡。密歇根大学金格里奇分校 该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。 鲸鱼是哺乳动物，在地质时代的始新世从陆地进化到海洋。 这一转变是由古鲸类或古代鲸鱼完成的，它们是现代新鲸类（须鲸和齿鲸）的祖先。 从完整或几乎完整的骨骼中可以知道四个阶段的过渡：第一，始新世偶蹄类陆地哺乳动物;第二，原鲸类古鲸类罗德霍鲸和马伊鲸;第三，蜥科古鲸类龙王鲸和多鲁东;第四，现代鲸鱼，最早出现在始新世晚期或渐新世。 第二阶段的古细菌是半水栖的，脚动力的游泳者，在海里觅食，但仍然在陆地上生育。 第三阶段的古细菌是完全水生的，尾巴驱动的游泳者，他们是第一个在海上分娩的。 这两个阶段在许多骨骼特征上有着不同的形态，它们之间的时间间隔约为1000万年（跨越中始新世的中Lutetian到Bartonian年龄）。 新的形态和时间的中间体的标本需要了解从半水生到完全水生的鲸鱼的过渡。 2005年至2008年与埃及矿产资源管理局和埃及环境事务局合作开展的实地工作表明，有可能收集到保存完好且非常完整的古鲸骨骼，这些骨骼来自古特提斯海的中鲁特阶到Bartonian绿砂（绿砂），这些绿砂在埃及西部沙漠中异常暴露。 这里提出的实地研究包括在埃及进行的三次为期两个月的年度考察，目的是发现和分析新的鲸鱼化石材料，填补早期鲸鱼进化的空白。 这些新证据对于推进跨适应区（在这种情况下，从陆地到海洋的过渡）的宏观进化知识至关重要。 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骼和培训博士后研究员来加强研究和教育基础设施。

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.