Collaborative Research: RUI: An Integrative Paleontological And Paleoenvironmental Study Of The Middle Cambrian Spence, Wheeler, And Marjum Soft-Bodied Faunas

寒武纪软体动物群的研究极大地增强了我们对后生动物进化中一些关键事件的理解。然而，谜题和未完全描述的寒武纪伯吉斯页岩型软体动物群仍然存在，伯吉斯页岩型保存为什么以及如何发生的问题也仍然存在。申请资助的拟议研究的直接目标是：1)利用最近在犹他州收集的资料，准备、描述、撰写专著，并将来自中寒武纪Spence组、Wheeler组和Marjum组的软体动物群的新分类群纳入植物学和古生物地理学框架；2)利用微量分析技术在标本水平上确定化石的地层学；3)利用新发展的微地层技术，将软体生物及其保存过程置于详细的古环境框架中。这项研究的智力价值在于解决了寒武纪古生物学和地质学中的一些谜题，从而实现了多重目标。首先，确定犹他动物群的特征将有助于确定这些地层与分布在全球的其他寒武纪软体动物群之间共有哪些分类群。这样就可以确定这些种属的地层和地理范围。其次，结合已有的信息，可以评估Spence， Wheeler和Marjum中各种节肢动物的系统发育关系。这些目标将增加我们对寒武纪生物地理学的理解，以及对动物进化早期重要事件的性质和拓扑结构的理解。此外，对三个主要的伯吉斯页岩类型地区进行深入的地层学和微地层学研究，将使我们对控制伯吉斯页岩动物在寒武纪保存的古环境因素和地层学过程有更精确的了解，并有助于我们理解为什么这种类型的保存是寒武纪独有的。由于这些鲜为人知的动物群的丰富性和重要性，以及整个研究区域的良好暴露和相对较低的泥岩变质等级，该项目还提供了一个难得的机会，在相互关联的背景下研究伯吉斯页岩型矿床的系统发育、古生态学和保存。一些将被研究的动物在堪萨斯大学（KU）的收藏中，并附有精确的地点数据。堪萨斯大学（University of Kansas）的名誉教授迪克·罗宾逊（Dick Robison）在与这项资助相关的领域也拥有丰富的专业知识。犹他大学的教授Sue Halgedahl和Richard Jarrard也同意将他们在犹他州收集的大量寒武纪伯吉斯页岩类软体动物提供给我们研究；同样，这些都伴随着精确的地点数据。这些因素中的每一个都将极大地促进这项拟议的研究。就更广泛的影响而言，该项目将有助于培训两名研究生，一名在堪萨斯大学，一名在加州大学河滨分校，他们将参加拟议的研究活动并参加科学会议。通过RUI项目，该项目还将为来自波莫纳学院的多名本科生提供实地和分析培训。波莫纳学院是一所只招收本科生的机构，也是凯克地质联合会的成员。

The study of Cambrian soft-bodied faunas has greatly enhanced our understanding ofsome key events in metazoan evolution. However, enigmas and incompletely describedCambrian Burgess Shale-type soft-bodied faunas still remain, as does the question of why andhow Burgess Shale-type preservation occurs. The immediate objectives of the proposed researchfor which funding is requested are: 1) to prepare, describe, monograph, and fit into aphylogenetic and paleobiogeographic framework new taxa from the Middle Cambrian softbodiedfaunas of the Spence Member and the Wheeler and Marjum Formations using recentcollections made from Utah; 2) to use microanalytical techniques to determine the taphonomy ofthe fossils at the specimen-level; and 3) to place the soft bodied organisms and the taphonomicprocesses involved in their preservation into a detailed paleoenvironmental framework usingnewly developed microstratigraphic techniques.The intellectual merit of this research is to address some enigmas in Cambrianpaleontology and geology, allowing multiple objectives to be attained. First, identifying andcharacterizing the elements of the Utah faunas will help establish which taxa are shared betweenthese formations and other Cambrian soft-bodied faunas distributed throughout the globe. Thus,the stratigraphic and geographic ranges of these species and genera can be determined. Second,in conjunction with pre-existing information, the phylogenetic relationships of the variousarthropods in the Spence, Wheeler, and Marjum can be evaluated. These objectives will increaseour understanding of Cambrian biogeography and also the nature and topology of importantearly episodes in animal evolution. Additionally, intensive taphonomic and microstratigraphicstudy of three of the principal Burgess Shale-type localities will lead to a refined understandingof the paleoenvironmental factors and taphonomic processes that controlled the preservation ofBurgess Shale faunas in the Cambrian, and will contribute to our understanding of why this typeof preservation is unique to the Cambrian. Due to the richness and significance of these poorlyknownfaunas, the excellent exposure across the study areas and the relatively low metamorphicgrade of mudstones hosting the soft-bodied faunas, this project also provides a rare opportunityto address phylogeny, paleoecology, and preservation in Burgess Shale-type deposits in aninterrelated context.Some of the faunas that will be studied are in collections housed at the University ofKansas (KU), and they are accompanied by precise locality data. There is also an emeritusprofessor at the University of Kansas, Dick Robison, with significant expertise in areas related tothis grant. Sue Halgedahl and Richard Jarrard, professors at the University of Utah, have alsoagreed to make their extensive collections of soft-bodied, Cambrian Burgess Shale-type faunasfrom Utah available to us for study; again, these are accompanied by precise locality data. Eachof these factors will greatly facilitate this proposed research.In terms of broader impacts, this project will contribute to the training of two graduatestudents, one at KU and one at the University of California, Riverside, who will participate in theproposed research activities and attend scientific meetings. Through the RUI program, thisproject will also contribute to the field and analytical training of multiple undergraduates fromPomona College, an undergraduate-only institution and member of the Keck geologyconsortium.