PRELIMINARY TERRESTRIAL PALYNOLOGICAL RE-INVESTIGATION OF THE TYPE COON CREEK LAGERSTÄTTE, TENNESSEE, USA

The type locality for the Campanian Coon Creek Formation, in McNairy County, Tennessee, is a well-known lagerstätte, a sedimentary deposit with abundant fossils. Exceptionally preserved marine invertebrate and vertebrate remains, including mollusks, crabs, and mosasaurs are found in these shallow shelf sediments. At the time of deposition, the type locality was an embayment proximal to the eastern margin of the Appalachia province and experienced alternately cool- and warm-water conditions, likely due to currents from both the Western Interior Seaway and Tethys. While marine in their entirety, the sediments contain significant quantities of terrestrial palynomorphs – especially near the top of the section – and thus provide a snapshot of adjacent upper Cretaceous terrestrial ecosystems that are not otherwise preserved in this region. A recently completed biostratigraphic study of widely spaced samples through the section suggested that more detailed examination of the terrestrial palynomorphs preserved in the section was warranted to refine first and last taxonomic occurrences in the section and explore variations in terrestrial ecosystems that contributed to the assemblages. In July 2022, the team of co-authors collected 27 additional samples from the type locality. In this study we present the preliminary results and interpretations of new biostratigraphic and paleoecological investigations of terrestrial palynomorphs recovered from the site.