Collaborative Research: Systematics, Paleoecology, and Extinction of Late Osagean Crinoids from Iowa, Illinois and Missouri

合作研究：爱荷华州、伊利诺伊州和密苏里州晚期海百合的系统学、古生态学和灭绝

• 批准号: 8705531
• 负责人: Thomas Kammer
• 金额: --
• 依托单位: West Virginia University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-11-15 至 1991-10-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8705531&HistoricalAwards=false
• 关键词: Collaborative; Research; Systematics; Paleoecology; Extinction

The proposed study involves both a detailed systematic revision of the crinoids from the late Osagean (Mississippian) Keokuk Limestone and the basal part of the Warsaw Formation in Iowa, Illinois, and Missouri, and a study of their depositional settings. Crinoids from the Keokuk and basal Warsaw have not received study in the latter half of this century, despite the fact that crinoids of this age in other areas are well understood, and these faunas are from the North American Standard Section of the Mississippian. Re.evaluation of these faunas will complete our understanding of the systematics, community paleoecology, and depositional occurrences of crinoid faunas from the late Osagean throughout the east.central United States. This in turn will enable us to interpret the constraints and controlling factors that were responsible for the distribution of late Osagean crinoids. We will test these new data against the environmental controls model, which is based on multivariate analysis of late Osagean crinoid faunas from the Borden deltaic complex in Indiana and Kentucky. Documentation of controlling factors operating on late Osagean crinoids is essential for a fundamental understanding of Paleozoic crinoids. The Osagean was witness to the maximum diversity known among crinoids, and yet at the close of the Osagean, crinoids suffered extreme extinction. Crinoid faunas after the terminal Osagean extinction were very different in taxonomic character and remained basically the same from the recovery following the extinction event until the terminal Paleozoic mass extinction. Results from the proposed study are prerequisite for posing larger questions on the evolution of Paleozoic crinoids.

这项拟议的研究包括对奥萨金(密西西比)晚期Keokuk石灰岩和爱荷华州、伊利诺伊州和密苏里州华沙组底部的海龙化石进行详细的系统修订，以及对它们的沉积环境进行研究。在本世纪后半叶，基奥库克和华沙基底部的海百合一直没有得到研究，尽管其他地区的海百合已经得到了很好的了解，这些动物群来自密西西比河的北美标准段。对这些动物群的重新评价将使我们对整个美国东部和中部的奥萨吉晚期松柏类动物群的系统学、群落古生态和沉积产状的认识更加全面。这反过来将使我们能够解释制约和控制因素，这些因素是导致奥萨奇晚期海百合分布的原因。我们将根据环境控制模型对这些新数据进行测试，该模型基于对印第安纳州和肯塔基州博登三角洲杂岩中的奥萨吉期晚期海百合动物群的多变量分析。记录对奥萨奇晚期海百合的控制因素对于从根本上理解古生代海百合是必不可少的。奥萨吉亚见证了海百合中已知的最大多样性，但在奥沙金末期，海百合遭受了极端的灭绝。奥萨金末次大灭绝后的海百合动物群在分类特征上有很大的不同，从大灭绝事件后的恢复到古生代末期的大灭绝，它们基本保持不变。拟议的研究结果是提出关于古生代海百合演化的更大问题的先决条件。