Resolving the phylogeny and biogeographic history of early Crocodylia through total evidence analysis and exceptionally preserved Eocene fossils from Vietnam

通过全面的证据分析和保存完好的越南始新世化石，解决早期鳄鱼的系统发育和生物地理学历史

• 批准号: 417629144
• 负责人: Dr. Márton Rabi, Ph.D.
• 金额: --
• 依托单位: Lehrstuhl für Terrestrische Paläoklimatologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/417629144?language=en
• 关键词: Resolving; phylogeny; biogeographic; history; early

Representatives of Crocodylia, the group including modern-day alligators, caimans, crocodiles, and gharials, formed a major element of lowland ecosystems during the Paleogene and have an extensive fossil record accordingly. This makes them an excellent model clade for addressing a broad range of questions in macroevolution such as the environmental drivers of biodiversity in deep time. Of particular interest, is their biogeographic history as intercontinental dispersals played a major role in their diversification facilitated by the warm high-latitude climate of the Eocene. The Paleogene biogeographic history of crocodylians remains largely uncertain because phylogenies including fossils are instable due to limited sampling. The most critical issues include the markedly poor Paleogene fossil record of Asia, a continent that evidently had a major role in the evolution of Crocodylia based on present-day diversity alone. Another major factor is the limited utilization of molecular data in phylogenetic inference in combination with morphology from extant and extinct species. We here propose to extensively expand sampling by the addition of fossil data from undescribed Eocene crocodylians collected by the University of Tübingen during a DFG BO 1550/11-1, 2 - funded project in Vietnam. The abundance, exceptional preservation, and diversity (representing each of the three major extant lineages with several ontogenetic stages) makes this new fossil assemblage by far the most important among crocodylian faunas from the Paleogene of Asia. The new material ranks among the best-preserved fossils from North America and Europe thereby, for the first time, allowing meaningful comparisons of faunas across Laurasia. Novel osteological data from the Vietnamese taxa as well as key species from Europe and North America will be combined with molecular data in order to elucidate the early diversification and Laurasian biogeographic history of Crocodylia. The expected results will have important implications for intercontinental paleogeographic reconstruction and faunal interchange during the early Paleogene.

鳄鱼科的代表，包括现代鳄鱼，鳄鱼，鳄鱼和gharials的群体，在古纪期间构成了低地生态系统的主要元素，并且相应地具有广泛的化石记录。这使它们成为解决宏观进化中广泛问题的绝佳模型进化枝，例如在深层生物多样性的环境驱动力。特别令人感兴趣的是，他们的生物地理历史是洲际分散在始新世温暖的高纬度气候制备的多元化中起着重要作用。鳄鱼的古生物地理历史在很大程度上仍然不确定，因为由于采样有限，系统发育包括化石是不稳定的。最关键的问题包括亚洲的古代化石记录明显较差，这一连续性在仅基于当今的多样性基于鳄鱼的演变中就具有重要作用。另一个主要因素是在系统发育推断中与扩展和灭绝物种的形态相结合的分子数据利用率有限。我们在这里建议通过在Tübingen大学在DFG BO 1550/11-1中收集的未描述的始新世鳄鱼中的化石数据进行广泛扩展采样，并在越南获得了资助的项目。丰度，卓越的保存和多样性（代表具有几个个体发育阶段的三个主要延伸线中的每一条）使得迄今为止这种新的化石组合是来自亚洲古纪的鳄鱼动物群中最重要的。新材料是北美和欧洲保存最完好的化石之一，因此首次可以在劳拉西亚进行有意义的比较。来自越南分类单元以及欧洲和北美的关键物种的新型骨学数据将与分子数据结合使用，以阐明早期多元化和劳拉西亚的生物地理史。预期的结果将对洲际古纪早期的洲际古地理重建和动物互换具有重要意义。