A RENEWED STUDY OF DEERPARKIAN (LATE PRAGIAN) BRACHIOPOD BIOGEOGRAPHY OF SOUTHEASTERN LAURENTIA AND ITS IMPLICATIONS FOR THE PALEOGEOGRAPHY OF THE PRESENT-DAY WESTERN HEMISPHERE

We are completing a taxonomic study of marine invertebrate fossils from the Glenerie Formation (late Deerparkian age, equivalent to the global late Pragian) of the Hudson Valley, New York. Correlative strata in New York include the Oriskany Formation and Connelly Conglomerate. The Glenerie fauna we studied was collected by Feldman over an extended period (1980-2021) and is dominated by brachiopods. This is the largest collection of Glenerie brachiopods recognized to date. Its revised study will be useful in further documenting the wide dispersion of the Oriskany-Glenerie fauna, both into NE Canada and to the southwest into Chihuahua and Sonora of northern Mexico, and Nevada. Commonly occurring brachiopod genera include Leptaenella, Costellirostra, Coelospira, Leptocoelia, Trematospira, Meristella, Meristina, Acrospirifer, Costispirifer, Metaplasia, Plicoplasia, Beachia, Prionothyris, Rensselaria, and Oriskania. The Glenerie brachiopod fauna is distinct from older Helderberg and younger Esopus faunas. Some brachiopods present in this interval can now be recognized as present in northern South America and suggest that the southeastern margin of Laurentia was very close to northern South America by Early Devonian time. Eastern North America, notably the Appalachian Basin and the craton to the southwest (i.e., Tennessee, Oklahoma, Missouri, Texas, Chihuahua, and Sonora) were part of a first-order biogeographic entity denoted as the Eastern Americas Realm. This realm reached its greatest extent during the Pragian-early Emsian interval, when four subprovinces are recognized: Appohimchi Subprovince (corresponding to eastern and southeastern Laurentia), Nevadan Subprovince, Colombian Subprovince (essentially the Sierra de Perijá along the Colombia/Venezuela border), and the Amazon Subprovince. The Appohimchi and Colombian subprovinces, although distinct at some levels, nevertheless share many species or related species, indicating their proximity by this time. This emerging similarity between the two subprovinces arose from an Early-Middle Devonian collision between southeastern Laurentia and northwestern South America which raised an extensive North-South trending mountain range.