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

拟议中的研究包括详细的系统修订的海百合从奥萨吉晚期（密西西比）Keokuk石灰岩和华沙形成的基础部分在爱荷华州，伊利诺伊州和密苏里州，和他们的沉积环境的研究。在本世纪的后半叶，来自基奥库克和华沙基底的海百合没有得到研究，尽管在其他地区的这个年龄的海百合已经很好地了解了，这些动物群来自密西西比的北美标准节。对这些动物群的重新评价将使我们对奥赛纪晚期美国中东部海百合动物群的系统学、群落古生态学和沉积事件的了解更加完整。这反过来将使我们能够解释的限制和控制因素，负责晚Osagean海百合的分布。我们将测试这些新的数据对环境控制模型，这是基于多变量分析的博登三角洲复杂的印第安纳州和肯塔基州奥萨吉晚期海百合动物群。控制因素的文件运作晚Osagean海百合是必不可少的古生代海百合的基本认识。奥萨吉人见证了海百合最大的多样性，然而在奥萨吉人结束时，海百合遭受了极端的灭绝。奥萨吉灭绝末期后的海百合动物群在分类学特征上有很大的不同，从灭绝事件后的恢复到古生代末期的大规模灭绝，海百合动物群基本保持不变。这项研究的结果是对古生代海百合演化提出更大问题的先决条件。

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.