Collaborative Research: Unearthing Antarctica's role in the Late Cretaceous Evolution of Flowering Plants

合作研究：揭示南极洲在白垩纪晚期开花植物演化中的作用

• 批准号: 1953993
• 负责人: Brian Atkinson
• 金额: $ 48.89万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1953993&HistoricalAwards=false
• 关键词: Collaborative; Research; Unearthing; Antarctica; role

Part I: Nontechnical DescriptionFlowering plants are the dominant land plant group on Earth today. They play essential roles in climate-life interactions and are fundamental for human well-being (health, food, materials). Despite their importance to us, their early evolution has remained enigmatic. Without the geological context of how these plants evolved, we will not fully understand their roles in regulating climate and structuring environments. This is important as terrestrial ecosystems today are undergoing many changes. The fossil record indicates that critical events relating to the early diversification of flowering plants occurred during the Cretaceous period (145–66 million years ago). Recent discoveries of fossil flowers and fruits from this time period have significantly furthered our understanding of early flowering plant evolution. However, the majority of these discoveries are from the Northern Hemisphere while similar discoveries from the Southern Hemisphere are relatively lacking. This project will address this paucity of data by collecting and describing Late Cretaceous flowering plant fossils from Western Antarctica and placing them in evolutionary frameworks to better understand early flowering plant evolution, biogeographic history, and Antarctica’s role in the formation of modern ecosystems. Western Antarctica is the only place in the Southern Hemisphere that is reported to contain Late Cretaceous-aged (100–66 million years ago) three-dimensionally preserved flowers and fruits. Therefore, the recovery and study of these fossils can meaningfully further our understanding of the early phases of flowering plant evolution. This work will result in the description of new species that will be placed in evolutionary analyses and biogeographic frameworks, which will help clarify the Cretaceous diversification of flowering plants in the Southern Hemisphere. These fossils will provide insights that will allow us to anticipate which plants might thrive in a warming Antarctic and world.Part II: Technical DescriptionThe Late Cretaceous diversification of flowering plants (angiosperms) in the Southern Hemisphere is poorly understood due in part to the limited amount of well-characterized fossil plant reproductive structures. Paleobotanical studies indicate that Antarctica was an important area for the Cretaceous diversification of flowering plants and is the only place in the Southern Hemisphere that is known to contain permineralized Late Cretaceous-aged angiosperm reproductive structures. The proposed research will elucidate Antarctica’s role in the evolution of angiosperms and assembly of modern ecosystems by recovering and characterizing Late Cretaceous Antarctic angiosperms, placing them within a phylogenetic context, and testing for biogeographic links between North America and Gondwana as has been observed for animals. Fieldwork will be conducted in the James Ross Basin of West Antarctica where previous reports and preliminary data indicate the presence of Late Cretaceous-aged floras that include structurally preserved reproductive structures. The exceptional preservation of these fossils allows us to record data essential for placing them in a phylogenetic framework from which their evolutionary and biogeographical context can be determined. The taxonomically informative and well-preserved angiosperm reproductive structures within the James Ross Basin are of a crucial age and from an important geographic area for understanding the phylogenetic diversification of Southern Hemisphere angiosperms and ecosystems. Collected fossils will be examined using standard physical techniques and microCT imaging. The study of these fossils will result in the description of new species and possibly higher taxa and provide a unique perspective into the floral diversity and composition of West Antarctica during the Cretaceous. In addition, the fossils will be placed within a phylogenetic framework, which will help to elucidate which lineages were diversifying in Antarctica.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

第一部分：非技术描述开花植物是当今地球上的主要陆地植物群，它们在气候与生命的相互作用中发挥着重要作用，并且对人类福祉（健康、食物、材料）至关重要，尽管它们对我们很重要，但它们的早期进化。如果不了解这些植物如何进化的地质背景，我们将无法完全了解它们在调节气候和构建环境方面的作用，因为当今的陆地生态系统正在经历许多变化。早期的开花植物的多样化发生在白垩纪时期（145-6600 万年前）。最近发现的这一时期的花朵和果实化石极大地加深了我们对早期开花植物进化的理解。北半球的类似发现相对缺乏，该项目将通过收集和描述来自西南极洲的晚白垩世开花植物化石并将其置于进化论中来解决数据匮乏的问题。更好地了解早期开花植物进化、生物地理历史以及南极洲在现代生态系统形成中的作用。 南极洲西部是南半球唯一据报道含有白垩纪晚期（100-6600 万年前）三种植物的地方。因此，对这些化石的恢复和研究可以有意义地进一步了解开花植物进化的早期阶段，从而描述新的物种。被置于进化分析和生物地理学框架中，这将有助于阐明南半球白垩纪开花植物的多样性，这些化石将提供见解，使我们能够预测哪些植物可能在变暖的南极和世界中繁衍生息。第二部分：技术。描述南半球白垩纪晚期开花植物（被子植物）的多样性知之甚少，部分原因是具有良好特征的古植物生殖结构化石数量有限。研究表明，南极洲是白垩纪开花植物多样化的重要地区，也是南半球唯一已知含有全矿化晚白垩世被子植物生殖结构的地方。拟议的研究将阐明南极洲在被子植物进化中的作用。通过恢复和表征晚白垩世南极被子植物来组装现代生态系统，将它们置于系统发育中实地考察将在南极洲西部的詹姆斯罗斯盆地进行，并测试北美和冈瓦纳大陆之间的生物地理联系，之前的报告和初步数据表明存在白垩纪晚期的植物群，其中包括结构上保存完好的植物群。这些化石的特殊保存使我们能够记录将它们置于系统发育框架中所必需的数据，从中可以确定它们的进化和生物地理背景。詹姆斯·罗斯盆地内的被子植物生殖结构处于关键年龄，并且来自一个重要的地理区域，对于了解南半球被子植物和生态系统的系统发育多样性将使用标准物理技术和显微 CT 成像进行检查。导致对新物种和可能更高的类群的描述，并为白垩纪时期西南极洲的花卉多样性和组成提供独特的视角。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Extending beyond Gondwana: Cretaceous Cunoniaceae from western North America

延伸到冈瓦纳大陆之外：来自北美西部的白垩纪库尼亚科

• DOI: 10.1111/nph.17976
• 发表时间: 2022
• 期刊: New Phytologist
• 影响因子: 9.4
• 作者: Tang, Keana K.;Smith, Selena Y.;Atkinson, Brian A.
• 通讯作者: Atkinson, Brian A.

Winged Fruits of Friisifructus aligeri gen. et sp. nov. from the Late Cretaceous of Western North America

• DOI: 10.1086/724745
• 发表时间: 2023-05-01
• 期刊: INTERNATIONAL JOURNAL OF PLANT SCIENCES
• 影响因子: 2.3
• 作者: Tang，Keana K.;Smith，Selena Y.;Atkinson，Brian A.
• 通讯作者: Atkinson，Brian A.