Rift dynamics and primate evolution at the close of the Paleogene: A view from the Rukwa Rift Basin

这个项目是一项古生物学调查，目的是了解灵长类动物和其他生物是如何应对大约2500万年前非洲环境的剧烈变化的。主要目标是确定新发现的动物群的特征，寻找更多的化石产区，并进行地质分析，以记录每个地区的准确年龄和环境背景。来自这种严重采样不足的时间和地理环境的化石，包括一些类人猿物种的最早证据，填补了进化记录中的一个空白，并使测试关于灵长类进化和生物转变的序列、时间和生态背景的假说成为可能。该项目包括一个跨学科研究团队，以指导职业生涯早期的科学家，并为本科生和研究生提供实践的实地和实验室研究机会，包括女性和STEM研究中代表性不足群体的学生。结果将通过国际期刊上的会议报告和出版物、面向普通受众的研讨会、专题讨论会/讲习班、互动科学宣传网站、博物馆展品和K-12学习活动来传播。该项目的研究区域记录了了解晚渐新世非洲陆地生态系统的一个重要窗口，产生了记录类人猿-类人猿分化的最古老的标本。在渐中新世边界附近，非洲阿拉伯和欧亚大陆之间的碰撞导致了大规模的动物群更替，最终非洲的大部分常驻生物群被入侵物种取代。这改变了捕食和竞争的格局，对生物多样性产生了深远的影响。该项目假设，非洲大陆灵长类群落组成的关键变化在渐新世过渡之前就已经发生了。最近的发现表明，东非早期的类人和类人猿进化发生在东非裂谷系统西支以前未知的构造活动的背景下，恰逢全球晚渐新世变暖事件，并在中新世晚期加剧的更大规模的动物群迁移之前。这些假设将使用从400米地质剖面收集的数据进行验证，该地质剖面包含各种不同的动植物，夹层火山沉积提供了年龄限制。研究方法结合了基于标本的显微镜、显微CT技术、形态测量和系统发育研究，以及地质分析，以记录研究地点的生态环境和地质年代学。

This project is a paleontological investigation to understand how primates and other organisms responded to dramatic environmental changes approximately 25 million years ago in Africa. The primary goals are to characterize a newly discovered fauna, find additional fossil-bearing localities, and conduct geological analyses to document the precise age and environmental setting for each locality. Fossils from this critically under-sampled temporal and geographic setting, including some of the earliest evidence of ape species, fill a gap in the evolutionary record and make it possible to test hypotheses regarding the sequence, timing and ecological context of primate evolution and biotic transitions. The project includes an interdisciplinary research team to mentor early-career scientists and provide hands-on field and laboratory research opportunities for undergraduate and graduate students, including females and students from underrepresented groups in STEM research. Results will be disseminated via conference presentations and publications in international journals, seminars for general audiences, symposia/workshops, interactive science outreach websites, museum exhibits, and K-12 learning activities.The study area for this project records an important window into Late Oligocene African terrestrial ecosystems, yielding the oldest specimens documenting the cercopithecoid-hominoid divergence. Near the Oligo-Miocene boundary, collision between Afro-Arabia and Eurasia resulted in large-scale faunal turnover, with eventual replacement of much of Africa's resident biota by invasive species. This altered the landscape of predation and competition, with profound implications for biodiversity. This project hypothesizes that key shifts in primate community composition were already occurring on the African continent prior to the Oligo-Miocene transition. Recent discoveries suggest that early hominoid and cercopithecoid evolution in eastern Africa took place against the backdrop of previously unrecognized tectonic activity in the western branch of the East African Rift System, coinciding with the global late Oligocene warming event, and pre-dating larger-scale faunal shifts that intensified later in the Miocene. These hypotheses will be tested using data collected from 400 m of geological section containing a diverse array of flora and fauna, with intercalated volcanic deposits providing age-constraint. Research methodologies integrate specimen-based microscopy, micro-CT techniques, morphometric and phylogenetic studies, together with geological analyses to document ecological setting and geochronology of the study sites.