Rescue of Late Eocene Vertebrates; Yuanqu Basin, China

袁那曲盆地是一个占地约350平方公里的山间构造。位于中国中部中条山脉范围内。该盆地的始新世至渐新世陆相岩石包含了亚洲这个时代脊椎动物化石的最好记录之一，包括，到目前为止，至少有50种哺乳动物和5种爬行动物。这些化石矿床是1916年由一位瑞典地质学家发现的，他的收藏构成了早期一本专著的核心中国的第三纪脊椎动物。自从这次早期的探险以来，古生物学家们访问了这个盆地，并在河底组收集了脊椎动物化石。因此，至少有20个分类群被添加到最初的名单中，其中许多代表了关于哺乳动物的宝贵材料。1993年，中华人民共和国中国将在黄河上修建一座大坝，至少15个重要化石遗址将被淹没。该项目是中美两国古生物学家的合作项目，目的是从这些地点取回化石，并确定沉没前的古地磁特征。这个项目的意义在于它提供了最后一个中国河提组抢救珍贵古生物资料的机会。该地区的地层是众所周知的，它有丰富的始新世晚期脊椎动物的记录。在该地区洪水泛滥之前，中美联合团队将从将丢失的地点打捞出含有化石的材料。这一点非常重要，因为这个特殊的地层有保存在沉积物中的形态完整的标本，因此，这些化石将揭示始新世-渐新世事件发生的气候、动物群和生物地理变化的动态间隔。

The Yuanaqu Basin is an intermontane structure covering about 350 sq. km within the Zhongtiao Range of central China. Eocene to Oligocene terrestrial rocks in this basin contain one of the best records for vertebrate fossils of this age in Asia, including, to date, at least 50 species of mammals and five of reptiles. These fossiliferous deposits were discovered in 1916 by a Swedish geologist whose collections formed the core of a monograph on early Tertiary vertebrates of China. Since this early expedition paleontologists have visited this basin and collected fossil vertebrates in the Heti Formation. As a result, at least 20 taxa have been added to the original list and many represent valuable material on mammals. In 1993 the People's Republic of China will build a dam on the Huanghe (Yellow) River, and at least 15 important fossil-bearing sites will be submerged. This project is a collaborative effort between Chinese and American paleontologists to retrieve fossils from these sites and characterize the paleomagnetics prior to submersion. %%% The significance of this project is that it offers the last opportunity to salvage valuable paleontological material from the Heti Formation in China. The stratigraphy of this region is well known and it has a rich record of vertebrates in the latter part of the Eocene. Prior to flooding of this region, the combined Chinese and American teams will salvage fossil bearing materials from the sites that will be lost. This is very important because this particular formation has morphologically complete specimens preserved in deposits, and as such, these fossils will shed light on a dynamic interval, when the climatic, faunal, and biogeographic changes of the Eocene-Oligocene event occurred.