10-4 Late Ordovician Brachiopod Morphology and Diversity Trends under Shallowing Conditions

Session: Undergraduate and Graduate Geoscience Student Showcase (Posters)

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Brachiopods have innumerable uses within the field of stratigraphy; however, little is known about how paleoenvironments influence brachiopod morphologies. While some research done in the latter part of the 20th century assessed brachiopod diversity trends at various water depths, a thorough understanding of the true extent of morphological change that these diversity trends represent is lacking. Many previous studies also lack certain morphological character data critical to understanding those important data trends. This study aims to identify meaningful variation among Late Ordovician brachiopod communities present at different water depths. This assessment includes a wide variety of characters with a preference for quantitative over qualitative data. The material used for this study was gathered from the Maysville, Kentucky area and the rock units are all a part of the Ordovician Cincinnati Arch sequence. Using lithostratigraphy outlined in previous literature, brachiopods from multiple high stand facies at varying water depths have been collected and analyzed using 3D modeling software and a new deep learning program, Deep Morph. This quantitative data is to be tabulated and evaluated using correspondence analysis and significance testing with emphasis on confidence intervals to determine the influence of water depth on profile and structural elements of brachiopod shells. So far, we expect to see a trend towards larger more robust genera as water depth decreases. However, an increased prevalence of immature forms and smaller species has been noted in near-shore environments. Understanding the effect of water depth on brachiopods not only has applications in stratigraphy as an environmental proxy but can also define important differences among genera and species. Determining what variations in character are due to habitat can help add weight to certain differences among brachiopods groups, and aid to delineate between various species and genera in a more meaningful way. 

Geological Society of America Abstracts with Programs. Vol. 58, No. 1, 2026

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