Doctoral Dissertation Research: Comparative paleoecology of three contemporaneous Early Miocene catarrhine sites in East Africa

博士论文研究：东非三个同时期早中新世卡他碱遗址的比较古生态学

• 批准号: 0524944
• 负责人: David Pilbeam
• 金额: $ 1.19万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0524944&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Comparative; paleoecology

When does absence of a species at a fossil site truly mean that the species was absent from a once living community? This question will be addressed by a comparative study of the East African primate fossil record. The East African fossil record between 21 and 17 million years ago (Early Miocene) contains abundant remains of early catarrhines (the mammalian group that includes monkeys, apes, and humans). The fossil sites of Songhor, Koru, and Napak in East Africa contain different combinations of catarrhine species, despite being very close in space and time (19-20 million). Some species are found at all sites, while others are found at only one. The goal of this dissertation research is to explain these differences and to understand their ecological significance. It has previously been proposed that these different catarrhine distributions are the result of habitat differences between these areas during the Miocene. If this were true, we would expect to find similar differences recorded in the rest of the mammalian fauna. The hypothesis that catarrhine differences are due to habitat differences will be tested through a comparative study of both the catarrhine and non-catarrhine mammalian fossils from these three sites. In addition, alternative reasons why these catarrhine assemblages might vary will also be tested. These include: (1) sampling bias, (2) preservational or taphonomic biases, and (3) fossil collecting biases. Each of these factors can substantially alter the composition of fossil assemblages, even if the living communities from which the fossils derived were identical. Therefore, testing for these factors is critical in any paleontological study that seeks to understand interlocality variation. Finally, data on the distributions of modern African catarrhine communities will be used to create models of what catarrhine distributions should look like in the Miocene fossil record. This research is important and interesting because the catarrhine fossils under study represent the earliest members of the monkey-ape-human lineage, including the earliest known monkey, and the earliest well-characterized ape. Further study of these fossils and their associated faunas will increase our understanding of the ecological differences among Early Miocene primates. This will have important implications for understanding later stages of catarrhine evolution, including that of our own species. In particular, this study will highlight the important effects that sampling biases have on the fossil record, a topic that is only rarely addressed in paleoanthropological research. Also, this research will have significance more widely in the biological sciences because it will incorporate methods from the fields of both paleontology and ecology. The broader impact of this project is that it will encourage international collaboration with researchers at the National Museums of Kenya and the Uganda Museums. Inclusion of traditionally underrepresented groups is addressed by promoting the active involvement of African researchers in this project. All fossil data collected will be integrated into the National Museums of Kenya database currently being designed so that the data can be disseminated widely to other researchers. In addition, results will be published in peer-reviewed journals and presented at scientific conferences.

什么时候一个物种在化石地点的消失真的意味着这个物种在一个曾经存在的群落中消失了？这个问题将通过对东非灵长类动物化石记录的比较研究来解决。 东非的化石记录在2100万至1700万年前（中新世早期），包含了大量早期卡他类（包括猴子、猿和人类的哺乳动物）的遗骸。 东非的松戈尔、科鲁和纳帕克化石遗址包含不同的卡他鼻类物种组合，尽管它们在空间和时间上非常接近（1900万至2000万）。 有些物种在所有地点都有发现，而另一些物种只在一个地点发现。 本论文研究的目的是解释这些差异，并了解其生态意义。以前有人提出，这些不同的卡他鼻分布是在中新世期间这些地区之间的栖息地差异的结果。 如果这是真的，我们将期望在其他哺乳动物群中发现类似的差异。卡他鼻的差异是由于栖息地的差异，这一假设将通过比较研究的卡他鼻和非卡他鼻哺乳动物化石从这三个网站进行测试。 此外，还将测试这些卡他鼻类组合可能不同的其他原因。这些包括：（1）采样偏差，（2）解释或埋藏偏差，（3）化石收集偏差。这些因素中的每一个都可以大大改变化石组合的组成，即使化石来源的生物群落是相同的。 因此，测试这些因素是至关重要的，在任何古生物学研究，试图了解异地变化。最后，现代非洲catarrhine社区的分布数据将被用来创建什么样的catarrhine分布应该看起来像在中新世化石记录的模型。这项研究既重要又有趣，因为正在研究的卡他鼻化石代表了猴-猿-人谱系的最早成员，包括已知最早的猴子和最早的特征明确的猿。 对这些化石及其相关动物群的进一步研究将增加我们对早中新世灵长类之间生态差异的理解。这将对理解卡他鼻演化的后期阶段具有重要意义，包括我们自己的物种。特别是，这项研究将突出采样偏差对化石记录的重要影响，这是一个在古人类学研究中很少涉及的话题。此外，这项研究将在生物科学中具有更广泛的意义，因为它将结合古生物学和生态学领域的方法。 该项目的更广泛影响是，它将鼓励与肯尼亚国家博物馆和乌干达博物馆的研究人员开展国际合作。 通过促进非洲研究人员积极参与这一项目，解决了将传统上代表性不足的群体包括在内的问题。 收集到的所有化石数据都将纳入目前正在设计的肯尼亚国家博物馆数据库，以便向其他研究人员广泛传播这些数据。此外，研究结果将发表在同行评审的期刊上，并在科学会议上发表。