The study of Cambrian soft-bodied faunas has greatly enhanced our understanding of some key events in metazoan evolution. However, enigmas and incompletely described Cambrian Burgess Shale-type soft-bodied faunas still remain, as does the question of why and how Burgess Shale-type preservation occurs. The immediate objectives of the proposed research for which funding is requested are: 1) to prepare, describe, monograph, and fit into a phylogenetic and paleobiogeographic framework new taxa from the Middle Cambrian softbodied faunas of the Spence Member and the Wheeler and Marjum Formations using recent collections made from Utah; 2) to use microanalytical techniques to determine the taphonomy of the fossils at the specimen-level; and 3) to place the soft bodied organisms and the taphonomic processes involved in their preservation into a detailed paleoenvironmental framework using newly developed microstratigraphic techniques. The intellectual merit of this research is to address some enigmas in Cambrian paleontology and geology, allowing multiple objectives to be attained. First, identifying and characterizing the elements of the Utah faunas will help establish which taxa are shared between these 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 various arthropods in the Spence, Wheeler, and Marjum can be evaluated. These objectives will increase our understanding of Cambrian biogeography and also the nature and topology of important early episodes in animal evolution. Additionally, intensive taphonomic and microstratigraphic study of three of the principal Burgess Shale-type localities will lead to a refined understanding of the paleoenvironmental factors and taphonomic processes that controlled the preservation of Burgess Shale faunas in the Cambrian, and will contribute to our understanding of why this type of preservation is unique to the Cambrian. Due to the richness and significance of these poorlyknown faunas, the excellent exposure across the study areas and the relatively low metamorphic grade of mudstones hosting the soft-bodied faunas, this project also provides a rare opportunity to address phylogeny, paleoecology, and preservation in Burgess Shale-type deposits in an interrelated context. Some of the faunas that will be studied are in collections housed at the University of Kansas (KU), and they are accompanied by precise locality data. There is also an emeritus professor at the University of Kansas, Dick Robison, with significant expertise in areas related to this grant. Sue Halgedahl and Richard Jarrard, professors at the University of Utah, have also agreed to make their extensive collections of soft-bodied, Cambrian Burgess Shale-type faunas from Utah available to us for study; again, these are accompanied by precise locality data. Each of these factors will greatly facilitate this proposed research. In terms of broader impacts, this project will contribute to the training of two graduate students, one at KU and one at the University of California, Riverside, who will participate in the proposed research activities and attend scientific meetings. Through the RUI program, this project will also contribute to the field and analytical training of multiple undergraduates from Pomona College, an undergraduate-only institution and member of the Keck geology consortium.
