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，旨在了解大约2500万年前非洲灵长类动物和其他生物如何应对剧烈的环境变化。主要目标是描述新发现的动物群的特征，寻找更多有化石的地点，并进行地质分析，以记录每个地点的精确年龄和环境背景。在这个采样严重不足的时间和地理环境中发现的化石，包括一些最早的猿类物种的证据，填补了进化记录的空白，并使有关灵长类动物进化和生物过渡的序列、时间和生态背景的假设得以检验。该项目包括一个跨学科研究团队，为早期职业科学家提供指导，并为本科生和研究生（包括女性和STEM研究中代表性不足群体的学生）提供动手实地和实验室研究的机会。研究结果将通过国际期刊上的会议报告和出版物、普通观众研讨会、专题讨论会/讲习班、互动科学推广网站、博物馆展览和K-12学习活动来传播。该项目的研究区域为研究晚渐新世非洲陆地生态系统提供了一个重要窗口，产生了最古老的标本，记录了蠓类与人猿的分化。在渐新世-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更替，最终入侵物种取代了非洲的大部分常住生物群。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。该项目假设灵长类群落组成的关键转变在渐新世-中新世过渡之前已经在非洲大陆发生。最近的发现表明，非洲东部早期人猿和石猿的进化发生在东非裂谷系西部分支以前未被认识到的构造活动的背景下，与全球晚渐新世变暖事件相吻合，并且早于中新世后期加剧的大规模动物转移。这些假设将使用从400米的地质剖面收集的数据进行测试，这些地质剖面包含各种各样的动植物，穿插的火山沉积物提供了年龄限制。研究方法包括基于标本的显微镜、微型ct技术、形态测量学和系统发育研究，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.