BRACHIOPOD ABUNDANCES AND DIVERSITY OF THE MIDDLE CREEK MEMBER: AN INTERPRETATION OF ENVIRONMENTAL CONDITIONS

At the Firefighter’s Memorial off of 87th Street in Kansas City, Missouri, an exposure of upper Pennsylvanian strata contains a highly fossiliferous limestone called the Middle Creek Member (MCM). While this particular stratum is known for its high fossil content, it has not been formally studied in recent times. As a result, foundational information about it is lacking, including a thorough description and analysis of both its sedimentary and fossil contents. Additionally, there is insufficient understanding of what these aspects reveal about the environmental conditions of the Kansas City area during the Pennsylvanian period. The MCM is densely packed with various, diverse marine invertebrates but it has the greatest diversity among brachiopods. Brachiopod assemblages have commonly been used for the reconstruction and evaluation of environmental conditions in Earth history. The occurrence of brachiopod varieties provides the unique opportunity to gain a better understanding of the rich fossiliferous nature of the MCM. In February of 2024, field work recorded brachiopod taxa and their relative abundances from six different sites along the northern roadcut of 87^th Street. A surface collection method was employed, and abundances were determined for each site. The abundances ranged from 76-240 brachiopods across the six sites. In total, 13 brachiopod taxa were identified. A biodiversity analysis using the Shannon Diversity Index (DI) model was done on each section and indicated that Section 3 and Section 5 had the highest and lowest DI, respectively, ranging from 1.02-1.69. The calculated mean DI was 1.385, indicating very low diversity. Neochonetes were the most abundant, making up 130 out of 189 brachiopods at one site and ranged between 21%-69% across all six. Hustedia followed (7%-43%), and the least abundant was Wellerella (0%-0.004%). Overall, this assemblage can help us infer that these brachiopods were living in a warm, shallow marine environment. Using the data collected, research was done to help us describe the makeup of the MCM as well as reconstruct and interpret what the ancient environment was like during the late Pennsylvanian.