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

始新世特提斯（埃及）第一批完全水生鲸鱼向尾部动力游泳的过渡p.d. Gingerich，密歇根大学该奖项是根据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。这种转变是由古鲸或古代鲸鱼完成的，它们是现代新鲸的祖先（神秘鲸或须鲸和齿鲸或齿鲸）。从完整或几乎完整的骨骼中可以得知四个过渡阶段：始新世偶蹄类陆生哺乳动物；II，原始古ococetes Rodhocetus和Maiacetus；第三，Basilosaurus和Dorudon太古鲸；第四种是现代鲸，最早出现在始新世晚期或渐新世。第二阶段的古牡蛎是半水生的，以脚为动力的游泳者，在海里进食，但仍在陆地上分娩。第三阶段的古牡蛎是完全水生的，以尾巴为动力的游泳者，它们是第一个在海上分娩的。这两个阶段在许多骨骼特征上存在形态上的差异，它们之间的时间差距约为1000万年（跨越中鲁特世到中始新世的巴尔顿时代）。新的形态和时间中间体的骨骼需要了解从半水生到完全水生鲸鱼的转变。与埃及矿产资源管理局和埃及环境事务局合作，从2005年到2008年进行的实地工作表明，有可能从古特提斯海的鲁特梯中部到巴尔顿海青绿石（绿地）收集到保存完好且非常完整的古鲸骨架，这些骨骼在埃及西部沙漠中引人注目。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考察，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带（从陆地到海洋的过渡）宏观进化的知识至关重要。这个项目更广泛的影响包括通过发现代表鲸鱼进化早期阶段的新骨架和培养一名博士后，加强研究和教育的基础设施。

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.