Extinction and Recovery in Terrestrial Ecosystems across the Permian-Triassic Boundary in South Africa

项目摘要：南非二叠纪-三叠纪边界陆地生态系统的灭绝与恢复[j] . Hallie J. Sims, Marion K. Bamford, Conrad C. labandeira2.52亿年前的二叠纪/三叠纪（P/Tr）边界被认为是海洋生物历史上最大规模的灭绝。陆生化石记录表明，在这段时间内，植物和昆虫的更替广泛而频繁，但由于明显缺乏跨越边界的连续陆生序列，对这一事件的解释受到阻碍。南非卡鲁盆地二叠纪和三叠纪压缩区系记录了当地植被的时序快照，从而为评估跨界植物群落的灭绝和生态重构提供了一个模型系统。此外，这些群落中昆虫食草的多样性和频率被保存在化石叶片、木材、种子和其他生殖器官上，可以用来评估植物-昆虫相互作用的模式。pi的项目结合了博物馆收藏标本的检查和新的实地工作，从跨越P/Tr边界的23个卡鲁地区大量收集植物大化石。孢粉学分析将使他们能够将这些遗址与当前的地质年代学信息结合起来，包括新的辐射测量日期和卡鲁已知的脊椎动物生物带。这项工作将使pi能够测试与植物群落组成和相对丰度变化有关的假设。通过整合植物及其相关的昆虫食草动物的定量数据，本研究将通过提供跨P/Tr边界在多个营养水平上的生态系统变化的第一个严格评估，帮助了解陆地生命如何应对显生界最具破坏性的灭绝。

PROJECT ABSTRACTEXTINCTION AND RECOVERY IN TERRESTRIAL ECOSYSTEMS ACROSS THE PERMIAN-TRIASSIC BOUNDARY IN SOUTH AFRICAEAR-0230024PIs: Hallie J. Sims, Marion K. Bamford, and Conrad C. LabandeiraThe Permian/Triassic (P/Tr) boundary 252 million years ago is recognized as the largest mass extinction in the history of marine life. The terrestrial fossil record indicates that there was widespread and elevated turnover in plants and insects during this interval, but interpretation of the event has been hindered by the apparent lack of a continuous terrestrial sequence spanning the boundary. The Permian and Triassic compression floras in Karoo Basin of South Africa record a temporal series of snapshots of local vegetation, and thus provide a model system to assess extinctions and ecological restructuring in plant communities across the boundary. In addition, the diversity and frequency of insect herbivory in these communities is preserved as damage on fossil leaves, wood, seeds, and other reproductive organs and can be used to assess patterns in plant-insect interactions. PIs project combines examination of specimens in museum collections and new field work to bulk collect plant macrofossils from 23 Karoo localities spanning the P/Tr boundary. Palynological analysis will allow them to integrate the sites with current geochronological information, including new radiometric dates and known vertebrate biozones in the Karoo. The work will allow PIs to test hypotheses related to changes in the composition and relative abundance within plant communities. By integrating quantitative data on plants and their associated insect herbivores, this research will help understand how terrestrial life responded to the most devastating extinction in the Phanerozoic by providing the first rigorous assessment of changes in ecosystems across the P/Tr boundary at multiple trophic levels.