Late Ordovician brachiopod faunal endemism and mass extinction during drastic climate change, ocean anoxia and sea-level fluctuations

剧烈气候变化、海洋缺氧和海平面波动期间奥陶世晚期腕足动物特有现象和大规模灭绝

• 批准号: RGPIN-2014-04075
• 负责人: Jin, Jisuo
• 金额: $ 2.19万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=654679
• 关键词: Late; Ordovician; brachiopod; faunal; endemism

Our concern about global warming today is its effect on sea level rise and biodiversity change. The study of modern global change in climate and biodiversity is confined to the scale of decade to millennium. Paleontologists investigate environmental and biodiversity changes in Earth history at a million-year scale based on fossil record preserved in sedimentary rocks and thus provide unique and valuable data and interpretations to complement studies on modern and recent global change. During the past 530 million years (myr) of the Phanerozoic Earth history, one of the two grandest episodes of global sea-level rises occurred in the Late Ordovician (460-443 myr ago), when much of North America was flooded by epicontinental seas, in which marine life thrived, with brachiopods being the dominant benthic shelly organisms. This was followed by a terminal Ordovician glaciation and mass extinction event. In this proposal, the rich brachiopod fossil record of North America will be studied to determine the responses of Late Ordovician marine benthic shelly faunas to drastic sea level changes. In particular, the following questions will be addressed: 1) How did the continental-margin brachiopod faunas give rise to, and was subsequently replaced by, the epicontinental-sea faunas during the Late Ordovician sea level highstand? 2) Why did the epicontinental brachiopod faunas become highly endemic during the Late Ordovician marine transgression but not during some other similarly high sea-level? and 3) Why did the terminal Ordovician glaciation cause a mass extinction, whereas other major glaciations did not? The approach to these questions is to trace the brachiopod evolution at the species, genus, community, and faunal levels from both continental-margin (e.g. Anticosti Basin, Cincinnati Arch, Mackenzie Mountains) to inland-basin (Hudson Bay, Michigan, and Williston basins) depositional environments through the Late Ordovician sea-level fluctuations, using cladistics, multivariate and other numerical analyses. Results from the proposed research can help us better understand modern global change from the perspective of million year-scale global climate-biodiversity changes in Earth history.

我们今天对全球变暖的关注是它对海平面上升和生物多样性变化的影响。对气候和生物多样性的现代全球变化的研究仅限于千年的十年规模。古生物学家根据在沉积岩中保留的化石记录以一百万年级的规模研究地球历史上的环境和生物多样性变化，从而提供了独特而有价值的数据和解释，以补充有关现代和全球变化的研究。 During the past 530 million years (myr) of the Phanerozoic Earth history, one of the two grandest episodes of global sea-level rises occurred in the Late Ordovician (460-443 myr ago), when much of North America was flooded by epicontinental seas, in which marine life thrived, with brachiopods being the dominant benthic shelly organisms.随后是末期奥陶纪冰川和质量灭绝事件。在该提案中，将研究北美丰富的腕足化石记录，以确定已故的奥陶纪海洋底栖动物雪莉·弗纳斯（Shelly Faunas）对急剧海平面变化的反应。特别是，将解决以下问题：1）大陆 - 边缘金属脚动物动物区系如何产生，并随后被晚期奥托维奇海平面高架期间的地下境动物动物区系取代？ 2）为什么在晚期奥托维奇海洋违法行为期间，epic骨腕足动物动物群变得高度流行，而在其他一些类似的海平面上则没有？ 3）为什么末期奥陶纪冰川冰期会导致大规模灭绝，而其他主要冰川却没有呢？解决这些问题的方法是从大陆 - 账户（例如Antental-carin，cantental-carin，Cincinnati Arch，Mackenzie Mountains）到内陆 - 巴斯辛（Hudson Bay）（Hudson Bay，Michigan，Michigan和Williston see）的陆地上的弗洛克群岛 - 其他数值分析。拟议的研究的结果可以帮助我们从地球历史上全年全球气候生物多样性变化的角度来更好地了解现代全球变化。