Preliminary Terrestrial Palynological Re-investigation of the Type Coon Creek Lagerstatte, Tennessee, USA

The type locality for the Campanian Coon Creek Formation, located in McNairy County, Tennessee, is a well-known lagerstatte, with exceptionally preserved marine invertebrate and vertebrate remains in shallow shelf sediments. At the time of deposit ion, the type locality was located in an embayment proximal t o t he eastern margin of the Appalachia province that 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 which are not otherwise preserved in this region. A recently completed biostratigraphic study of rangefinder widely-spaced samples through the section suggested that the increase in terrestrial input up-section may be the result of increased fluvial input, as total marine microfossil abundances remain largely unchanged. The biostratigraphic study suggested that more detailed examination of the terrestrial palynomorphs preserved in the section was warranted. In July 2022, the team of co-authors collected 27 fresh samples from the type locality. In this study we present the preliminary results of new biostratigraphic and paleoecological investigations of terrestrial palynomorphs recovered from the site.https://scholarworks.moreheadstate.edu/celebration_posters_2024/1047/thumbnail.jp

Stratigraphy and Vertebrate Fauna of the Lower Shale Member of the Aguja Formation (Lower Campanian) in West Texas

The lower shale member of the Aguja Formation is one of only a few terrestrial stratigraphic units of early Campanian age in North America. Apart from a prolific microfossil site that yielded the Lowerverse local fauna, the lower shale is sparsely fossiliferous, and very little is known about its larger vertebrate fauna. Most of the specimens collected thus far are fragmentary, but among these are a hybodontid shark, an amiid fish (Melvius sp.), and bothremydid, trionychid, nanhsiungchelyid (Basilemys sp.), and baenid (cf. Denazinemys sp.) turtles. An isolated osteoderm is referable to the alligatoroid crocodylian Deinosuchus sp. A partial skull and skeleton of a goniopholidid crocodyliform is the most complete specimen recovered thus far, and likely represents a new genus and species. The most abundant dinosaur in the fauna is a new genus and species of hadrosaur. A partial pelvis and metatarsus of an ornithomimid dinosaur also likely represents a new taxon. Indeterminate tyrannosaurid, dromaeosaurid, ceratopsid, and nodosaurid dinosaurs are represented. The lower Two Medicine Formation in Montana, lower Wahweap Formation in Utah, and Menefee Formation in New Mexico bear the only other terrestrial vertebrate faunas of broadly comparable age in North America. The Aguja lower shale fauna is allied with ‘southern’ faunas in New Mexico and Utah in sharing the amiid fish Melvius, the baenid turtle Denazinemys, bothremydid turtles, and goniopholidid crocodyliforms. These taxa are absent in para-contemporaneous faunas of Montana and Alberta. Non-marine strata of early Campanian age do not appear to be present farther south in Mexico, and so the lower Aguja fauna is significant in documenting latitudinal variation in early Campanian continental environments

Driver mutations of the adenoma-carcinoma sequence govern the intestinal epithelial global translational capacity

Deregulated global mRNA translation is an emerging feature of cancer cells. Oncogenic transformation in colorectal cancer (CRC) is driven by mutations in APC, KRAS, SMAD4, and TP53, known as the adenoma-carcinoma sequence (ACS). Here we introduce each of these driver mutations into intestinal organoids to show that they are modulators of global translational capacity in intestinal epithelial cells. Increased global translation resulting from loss of Apc expression was potentiated by the presence of oncogenic KrasG12D. Knockdown of Smad4 further enhanced global translation efficiency and was associated with a lower 4E-BP1-to-eIF4E ratio. Quadruple mutant cells with additional P53 loss displayed the highest global translational capacity, paralleled by high proliferation and growth rates, indicating that the proteome is heavily geared toward cell division. Transcriptional reprogramming facilitating global translation included elevated ribogenesis and activation of mTORC1 signaling. Accordingly, interfering with the mTORC1/4E-BP/eIF4E axis inhibited the growth potential endowed by accumulation of multiple drivers. In conclusion, the ACS is characterized by a strongly altered global translational landscape in epithelial cells, exposing a therapeutic potential for direct targeting of the translational apparatus