Bivalve Richness and Ecological Diversity of the End-Triassic Mass Extinction: Faunal Analyses from the West-Tethyan Lombardy, La Spezia and K?ssen Basins (Italy and Austria)

三叠纪末大规模灭绝的双壳类丰富度和生态多样性：西特提斯伦巴第、拉斯佩齐亚和克森盆地（意大利和奥地利）的动物区系分析

• 批准号: 0518605
• 负责人: Christopher McRoberts
• 金额: $ 5.09万
• 依托单位: SUNY College at Cortland
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0518605&HistoricalAwards=false
• 关键词: Bivalve; Richness; Ecological; Diversity; End

Late Triassic extinctions are known to have severely affected many invertebrate andvertebrate taxa from the marine and non-marine realms; however, the precise timing,magnitude, and ultimate cause(s) of the biotic crisis remain poorly understood. Recentlypublished and unpublished high-resolution isotope stratigraphy coupled with preliminarybivalve collections reveals an abundance of ecologically significant bivalves near aninitial negative excursion in -13C and now permits precise correlation between nearly allknown Triassic-Jurassic boundary sections. To understand better which organisms wereaffected and the sequence of events in the late Triassic, I propose research involving ananalysis of taxonomic richness and paleoecology of Triassic-Jurassic bivalve faunas ofthe Lombardy, La Spezia and Kossen Basins of the western Tethys By virtue of theirabundance and richness in Triassic/Jurassic boundary beds within these key sections,bivalve mollusks provide an ideal group with which to test hypotheses surrounding thetempo and mode of extinction. Two related hypotheses will be investigated: (i) followinga period of ecologic stability, the end-Triassic bivalve extinction was both severe andabrupt; and (ii) bivalves within the extinction and early survival interval exhibit anecologic pattern of selective extinction and survival. To address these questions, Ipropose intensive field and institutional based research to: (i) revise and develop newtaxonomic data on latest Triassic through earliest Jurassic bivalve fauna from the westernTethyan realm; and (ii) to develop high-resolution paleoecologic and paleoenvironmentaldata from identified stratigraphic sections spanning the Triassic/Jurassic boundary fromfive critical sections identified from the Lombardy, La Spezia and Kossen Basins of Italyand Austria. A taxonomic revision of west-Tethyan bivalves, which will involveextensive institutional-based research at major European repositories, has never beenattempted and is long overdue. Paleoecologic analyses will entail bed-by-bed analyses ofboundary intervals in which abundance, diversity, and trophic data will be collected fromstatistically large samples combined with taphonomic and sedimentologic data within ahigh-resolution biochronologic and chemostratigraphic framework. This work willinvolve substantial new collaborations with scientists from Italy, Austria and TheNetherlands with expertise in micropaleontology, palynology, stable isotopegeochemistry and regional geology, The research will also actively involveundergraduate students, both as assistants and as independent researchers and provide fortheir training and preparation for future graduate studies. The work proposed here willhave broad significance for the interpretation of biotic patterns surrounding the end-Triassic mass extinction. The expected outcome of a revised taxonomy ofRhaetian/Hettangian bivalves of the Kossen Basin will, after more than 100 years, finallyprovide sound base-line taxonomic data from which to test hypotheses surrounding thetiming, magnitude, and mode of the end-Triassic extinction.

众所周知，晚三叠世的灭绝严重影响了海洋和非海洋领域的许多无脊椎动物和脊椎动物分类群；然而，生物危机的确切时间、规模和最终原因(S)仍然知之甚少。最近公布和未公布的高分辨率同位素地层学与初步的双壳类采集相结合，揭示了在-13C初始负漂移附近有丰富的具有生态意义的双壳类，现在允许在几乎所有已知的三叠系-侏罗系界线剖面之间进行精确对比。为了更好地了解晚三叠世受影响的生物和事件序列，我建议进行研究，分析西特提斯的伦巴第盆地、拉斯佩齐亚盆地和科森盆地三叠纪-侏罗纪双壳动物群的分类丰富度和古生态，因为它们在这些关键剖面内的三叠纪/侏罗纪界线层中的丰富度和丰富度，双壳类软体动物提供了一个理想的类群来检验围绕物种和灭绝模式的假说。两个相关的假说将被研究：(I)在生态稳定期之后，三叠纪末期双壳类的灭绝既严重又突然；(Ii)在灭绝和早期生存区间内的双壳类呈现选择性灭绝和生存的生态模式。为解决这些问题，我提议进行深入的实地和机构性研究，以：(1)修订和编制关于西特提斯界最早的侏罗纪双壳动物群的新的三叠纪分类数据；(2)从已查明的跨越三叠纪/侏罗纪界线的地层剖面中编制高分辨率的古生态和古环境数据，这些地层剖面是从意大利和奥地利伦巴第盆地、拉斯佩齐亚盆地和科森盆地查明的五个关键剖面中确定的。对西特提斯双壳类的分类修订，将包括在欧洲主要储存库进行广泛的基于机构的研究，从来没有尝试过，而且早就应该进行了。古生态分析将需要逐层分析界线区间，在这些区间内，丰度、多样性和营养数据将从高分辨率生物年代学和化学地层学框架内的统计大样本结合挖掘学和沉积学数据收集。这项工作将涉及与意大利、奥地利和荷兰在微古生物学、孢粉学、稳定同位素化学和区域地质学方面有专长的科学家开展大量新的合作，这项研究还将积极吸收本科生作为助理和独立研究人员参与，并为他们今后的研究生学习提供培训和准备。这项工作将对解释三叠纪末期大灭绝的生物模式具有广泛的意义。科森盆地Rhaetian/HetTangian双壳类分类修订后的预期结果将在100多年后最终提供可靠的基线分类数据，以检验围绕三叠纪末期灭绝的时间、规模和模式的假说。