REVISION OF THE LATE CRETACEOUS (GULFIAN) ECHINODERM FAUNA OF THE CENTRAL GULF STATES

It has been over 50 years since Cooke (1953) produced his comprehensive work on Late Cretaceous American echinoids. While Cooke's monograph did not specifically focus on Gulf Coast taxa, his work has generally been accepted as the primary reference for Alabama and Mississippi echinoids. In the years following Cooke's work, the echinoid, as well as the crinoid, and asterozoan faunas of Alabama and Mississippi have virtually been ignored. Additionally, during last 50 years many generic and familial assignments have been changed and revised.

Recently, several new species of the cassiduloid echinoid Hardouinia have recently been recognized in late Santonian to early Campanian deposits in both states. Several new species of the burrowing echinoids Linthia and Hemiaster that dominate a sandy marl horizon just above the laggy basal Prairie Bluff Formation (Maastrichtian) have also been uncovered.

The crinoid Uintacrinus socialis, an important stratigraphic marker for late Santonian deposits in the Western Interior, has now been found in the Tombigbee Sand Member (Eutaw Formation) in Mississippi. The bathycrinid Dunnicrinus, published from late Maastrichtian deposits in Mississippi, the Netherlands, and Delaware, is now recorded from the Tombigbee Sand, Demopolis (Campanian-Maastrichtian), and Ripley (early Maastrichtian) Formations of Mississippi. The type of Borgueticrinus alabamensis, the only specimen known to exist of this species, is now officially lost, requiring a search for neotypes.

Asteroids, never before described from Mississippi or Alabama, are now recognized from the Cretaceous therein. Articulated goniasterids are known from the Mooreville Formation of Alabama. The Bluffport Marl Member of the Demopolis Formation has yielded many individual marginal ossicles belonging to the goniasterid Metopaster, heretofore known in the Southeast only from the younger Ripley Formation of Tennessee.

In light of the new echinoderm taxa and occurrences, the literature is in dire need of revision and updating. Together, these new species and species occurrences will have profound biostratigraphic, biogeographic, and paleoecological implications for the Gulf Coast region.