RECONSTRUCTING THE TRIASSIC VERTEBRATE FAUNA OF THE DEEP RIVER BASIN (NEWARK SUPERGROUP: CHATHAM GROUP), NORTH CAROLINA BASED ON NEW DISCOVERIES

Recent efforts taking advantage of artificial outcrop (quarries) and screenwashing for microvertebrates have greatly increased our knowledge of the diversity of vertebrate assemblages from the Deep River basin in North Carolina, simultaneously revealing more fully aquatic and typically terrestrial taxa. The semiaquatic phytosaur Rutiodon carolinensis Emmons is occasionally identifiable in Chatham Group strata, but isolated phytosaur teeth or bones should be referred to Phytosauridae indet. A particularly rich Pekin Formation locality yields semionotids, coelacanthids, temnospondyls, a rhynchosaur, phytosaurs, a rauisuchian, two new aetosaurs, a new crocodylomorph, dicynodonts, and the traversodont cynodont Boreogomphodon. Fragmentary fossils from the Cumnock Formation in the Wadesboro sub-basin include redfieldiids, lungfish, metoposaurid temnospondyls, and two phytosaur skulls, one with an associated skeleton. In the Sanford sub-basin an extensive microvertebrate Cumnock Formation assemblage is spectacularly diverse, yielding redfieldiids, semionotids, Arganodus (a lungfish), temnospondyls, Colognathus, lepidosaurs, phytosaurs, a rauisuchian, the venomous archosauriform Uatchitodon schneideri, Revueltosaurus olseni, Boreogomphodon, and the dromatheriid Microconodon. In contrast to the lower units, the Sanford Formation yields relatively few taxa identifiable to genus level, but does yield osteichthyans, temnospondyls, and phytosaurs. The stratigraphically problematic “Lithofacies Association II” of the Durham sub-basin yields additional lungfish and an exceedingly rare record (for the Newark Supergroup) hybodont shark (aff. Lissodus). The lungfish and sharks are both closely related to taxa known from western North America, Africa, and Europe, and are only found as extremely small fossils. Aetosaurs, Postosuchus, sphenosuchians, and revueltosaurs are all fully terrestrial animals that are comparatively rare in other Newark Supergroup basins.