THE INFLUENCE OF SEQUENCE STRATIGRAPHY ON NICHE MODELING OF MARINE MOLLUSKS ACROSS THE K-PG BOUNDARY IN THE U.S. GULF COASTAL PLAIN

Ecological niche modeling of fossil taxa (PaleoENM) is instrumental in addressing significant questions regarding species biogeography, evolutionary history, and responses to environmental change. While PaleoENM has been applied to study niche dynamics in deep time, little attention has been given to the influence of sequence stratigraphy on this modeling process. The geographic distribution of species is largely influenced by biotic and abiotic factors in the environment. However, in the fossil record, depositional processes shaping basin stratigraphy add complexity. Unlike modern studies that gather occurrence and environmental data directly from current environments, fossil data is collected from stratigraphic sections where preservation is strongly influenced by depositional processes. Understanding how sequence stratigraphy affects niche modeling results and paleoecological interpretations of fossil organisms is therefore crucial. The use of large datasets from databases lacking sequence stratigraphic information can lead to erroneous results that do not accurately represent the niche of the studied organism. This study explores the impact of sequence stratigraphic architecture on niche modeling of marine mollusks in latest Cretaceous and earliest Paleogene deposits in the U.S. Gulf Coastal Plain. We compare PaleoENMs generated using databases with limited sequence stratigraphic information to those derived from sections with assigned depositional systems tracts. Additionally, we assess the variation in niche modeling results obtained from different systems tracts (e.g., high stand vs. transgressive systems tracts) to evaluate whether model performance is influenced by sampling at different stages of a sedimentary sequence. This work has the potential to refine the methodology used to reconstruct ecological niches of fossil taxa, thus enhancing the accuracy and reliability of paleoecological interpretations.