DISSERTATION RESEARCH: Geographic complexity in the recovery of terrestrial vertebrate assemblages from mass extinction

论文研究：陆地脊椎动物群从大规模灭绝中恢复的地理复杂性

• 批准号: 1501097
• 负责人: Christian Sidor
• 金额: $ 1.59万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501097&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Geographic; complexity; recovery

This project will improve our understanding of how terrestrial life diversified after the largest extinction event of the last 500 million years. This event took place just over 252 million years ago at the boundary between the Permian and Triassic periods, when more than 70% of terrestrial animals went extinct. The fossil record is one of the main sources of data for many questions concerning the history of life on Earth. For the end-Permian event, our understanding of what occurred on land is known almost entirely from just two places - Russia and South Africa. This new research will build a database of fossil material belonging to terrestrial vertebrate animals from two additional places - Tanzania and Zambia. Before the extinction the fossil communities at those two new locations were similar to those of South Africa, but afterwards they were very different, and included new animals such as close relatives of mammals and, surprisingly, early relatives of the first dinosaurs. This research will combine data collected from recent research with that stored in museums across Europe and Africa to develop the most extensive fossil database of end-Permian land animals. This will allow paleontologists to determine diversification patterns across a larger region than has ever been done for this time period, and to discover the reasons that particular species survived the largest mass extinction event of all time and subsequently thrived. This project will synthesize several facets of diversity among terrestrial tetrapods, including species richness, evenness, relative abundances, trophic structure, and ecological niche diversity, and adds a new component of geographical complexity from poorly-sampled basins in Tanzania and Zambia (TZAM). Substantial fieldwork there in recent years has confirmed that the sedimentary rocks can be correlated with those of South Africa and Russia, and can therefore act as independent tests of hypotheses about the extinction and recovery processes. Preliminary data indicate that a homogeneous fauna existed between TZAM and South Africa before the extinction event, but that during the recovery process ecosystems fragmented, resulting in increased levels of endemism and biogeographic differentiation. This project aims to test hypotheses related to ecological structure and biogeographic patterns of vertebrate communities on either side of the end-Permian extinction, both within and between basins. Additionally, the researchers will test in deep time an ecological hypothesis developed for extant species, the abundance-range hypothesis.

该项目将加深我们对过去 5 亿年来最大的灭绝事件之后陆地生命如何多样化的理解。这一事件发生在 2.52 亿年前的二叠纪和三叠纪交界处，当时超过 70% 的陆地动物灭绝了。化石记录是有关地球生命历史的许多问题的主要数据来源之一。对于二叠纪末事件，我们对陆地上发生的事情的了解几乎完全来自两个地方：俄罗斯和南非。这项新研究将建立一个来自另外两个地方——坦桑尼亚和赞比亚——的陆生脊椎动物化石材料的数据库。在灭绝之前，这两个新地点的化石群落与南非的化石群落相似，但灭绝之后却截然不同，其中包括新的动物，例如哺乳动物的近亲，令人惊讶的是，还包括第一批恐龙的早期亲戚。这项研究将把最近研究中收集的数据与欧洲和非洲博物馆中存储的数据结合起来，开发最广泛的二叠纪末陆地动物化石数据库。这将使古生物学家能够确定比这一时期更大的区域的多样化模式，并发现特定物种在有史以来最大规模的灭绝事件中幸存下来并随后蓬勃发展的原因。该项目将综合陆地四足动物多样性的多个方面，包括物种丰富度、均匀度、相对丰度、营养结构和生态位多样性，并从坦桑尼亚和赞比亚（TZAM）的贫采样盆地添加地理复杂性的新组成部分。近年来，那里的大量实地考察证实，沉积岩可以与南非和俄罗斯的沉积岩进行关联，因此可以作为有关灭绝和恢复过程的假设的独立检验。初步数据表明，在灭绝事件之前，TZAM 和南非之间存在同质动物群，但在恢复过程中，生态系统支离破碎，导致特有性和生物地理分化程度增加。该项目旨在检验与二叠纪末灭绝两侧盆地内部和盆地之间脊椎动物群落的生态结构和生物地理模式相关的假设。此外，研究人员还将深入测试为现存物种提出的生态假说，即丰度范围假说。