Mammalian Faunas Across the Middle-Late Paleocene Boundary in Western North America

古新世代表了哺乳动物，特别是胎盘动物经历了一次重大的适应性辐射并成为主要陆地动物的时间。几乎一半已知的新生代哺乳动物的有序多样性被认为出现在古新世，其中许多第一次出现在北美。因此，这一地质时期在哺乳动物的历史上非常重要，但与新生代的任何后期相比，人们对古新世哺乳动物的多样性和组成的了解较少。特别薄弱的是我们对古新世中期到晚古新世(即从托雷约期ı到！)的哺乳动物历史的了解。敬蒂凡尼亚的ıTi！北美洲陆生哺乳动物时代)，当时动物群发生了重大变化。这种动物群的更替以前被归因于气候变化和洲际迁徙；然而，我们最近的工作表明，在边界附近没有发生大规模移民到西部内陆地区，而且动物群变化的情况比之前假设的更复杂。通过大幅增加To/Ti边界附近的大样本数量，该项目将为研究这一重要时段的动物群周转提供最详细的信息。特别是来自一个地方的初步收藏。宾果采石场，表明这对我们对TO/Ti转变的理解至关重要。对这些标本的研究，包括对宾果采石场标本的研究，将极大地增加对TO/Ti哺乳动物的系统发育、功能形态、古生态学和生物地层学的了解，并为分析动物群的更替提供基础。

The Paleocene Epoch represents the time during which mammals, particularly placentals, underwent a major adaptive radiation and became dominant land animals. Almost one-half of the known ordinal diversity of Genozoic mammals is thought to have arisen in the Paleocene, and many of these first appearances are in North America. This geologic interval is therefore of great importance in the history of mammals, yet less is known about mammalian diversity and composition during the Paleocene than during any of the later epochs of the Genozoic. Particularly weak is our knowledge of mammalian history during the transition from the middle to late Paleocene (i.e., from the Torrejonian ıTo! to the Tiffanian ıTi! North American Land-Mammal Ages), when there was a significant change in the fauna. This faunal turnover was previously ascribed to climatic change and intercontinental migrations; however, our recent work indicates that no major immigrations into the Western Interior occurred near the boundary, and that the scenario of faunal change was more complex than previously hypothesized. By substantially increasing the number of large samples near the To/Ti boundary, this project will have provided the most detailed information with which to study faunal turnover during this important interval. Preliminary collections from one locality n particularly. Bingo Quarry,indicate that it is crucial to our understanding of the To/Ti transition. Study of these samples, including those from Bingo Quarry, will significantly augment knowledge of the phylogeny, functional morphology, paleoecology, and biostratigraphy of To/Ti mammals and provide the foundation for analyses of faunal turnover.