Collaborative Research: Andean Fossil Mammals--Phylogenetic and Geologic Implications

合作研究：安第斯哺乳动物化石-系统发育和地质意义。菲尔德自然历史博物馆的约翰·J·弗林博士和芝加哥大学的达林·A·克罗夫特博士获得了一笔赠款，用于收集和研究智利中部安第斯山脉的哺乳动物化石，并对该地区进行地质调查。这项研究将澄清南美哺乳动物进化鲜为人知的方面，并有助于揭开安第斯山脉复杂的地质历史。将进行野外采集和勘察，以发现不同年龄的哺乳动物化石的新地点和新组合。一旦准备好，这些化石将在科学文献中进行描述和分析，以了解气候变化等因素如何影响物种多样性。这些化石在火山岩中的不同寻常的出现将使各种“绝对”地质测年方法的应用成为可能，从而为这些化石提供准确的年龄和更准确的科学分析。在过去8000万年的大部分时间里，南美洲都是一个与世隔绝的大陆。两个多世纪以来，因这种与世隔绝而产生的高度特殊的哺乳动物吸引了生物学家和古生物学家的兴趣。大约15年前，弗林博士和他的同事们出人意料地在南美洲这个地区发现了第一批哺乳动物化石。通过对哺乳动物化石的研究，研究小组表明，含有化石的岩石比之前假设的要年轻近1亿年。这一发现彻底改变了人们对该地区构造历史的理解。此外，这一发现和其他发现帮助填补了南美哺乳动物历史上重要的“缺失篇章”，例如，导致最近承认了一个新的南美洲陆地哺乳动物时代，并提供了世界上最古老草原的证据。该项目建立在早期工作的基础上，侧重于特定的地理区域和特定的哺乳动物群体(啮齿动物、已灭绝的以植物为食的形式、有袋类动物等)。

Collaborative Research: Andean Fossil Mammals-Phylogenetic and Geologic Implications.A grant has been awarded to Dr. John J. Flynn of the Field Museum of Natural History and Dr. Darin A. Croft of the University of Chicago to collect and study fossil mammals from the Andes Mountains of central Chile, and to carry out geological investigations of the region. This study will clarify poorly known aspects of South American mammal evolution, and help unravel the complex geologic history of the Andean mountain chain. Field collecting and reconnaissance will be undertaken to discover new localities and assemblages of fossil mammals of different ages. Once prepared, these fossils will be described in the scientific literature and analyzed in order to understand how factors such as climate change affect species diversity. The unusual occurrence of these fossils in volcanic rocks will enable the application of various "absolute" geologic dating methods, providing precise ages for these fossils and more accurate scientific analyses.South America was an isolated continent for most of the last 80 million years. The highly peculiar mammals arising in response to this isolation have captured the interest of biologists and paleontologists for more than two centuries. Some 15 years ago Dr. Flynn and his colleagues unexpectedly discovered the first fossil mammals from this region of South America. By studying the fossil mammals, the team showed that the fossil-containing rocks were nearly 100 million years younger than previously assumed. This discovery has revolutionized understanding of the region's tectonic history. Moreover, this and other discoveries have helped to fill in important "missing chapters" in South American Mammal history, leading, for example, to the recent recognition of a new South American Land Mammal Age and evidence of the world's oldest grasslands. This project builds on earlier work, focusing on targeted geographic areas and particular groups of mammals (rodents, extinct plant eating forms, marsupials, etc.).