PRELIMINARY STUDY OF FIVE NEW SPECIES OF ECHINOIDEA FROM THE EOCENE OF THE SOUTHEASTERN UNITED STATES

Extensive collecting in the middle to late Eocene age strata of the southeastern United States has uncovered five new species of Echinoidea, two of which represent new genera in the Eocene age faunas of the region. The authors are in the process of formalizing these new species and determining what the addition of these species can reveal about the paleoecology of their respective faunas and affinities with correlative Caribbean faunas.

Specimens of the genus Haimea were collected from the upper Eocene age Ocala Limestone in a quarry north of Marianna, Jackson County Florida. Though the genus is well represented in the Caribbean Eocene age faunas, this is the first species described from the United States, and represents the northernmost occurrence of the genus. Haimea n. sp., occur here with a diverse echinoid assemblage, including: Oligopygus haldemani (Conrad), Weisbordella johnsoni (Twitchell), Rhyncholampas conradi (Conorad), Eurhodia patelliformis (Bouve’), Agassizia cleivi (Cotteau) and Phyllacanthus mortoni (Conrad).

Collecting in the mid-Eocene age Moodys Branch Formation has provided specimens of an undescribed species of Echinolampas from two localities in Covington County, Alabama. This species occurs with Periarchus lyelli (Conrad), Fibularia texana (Twitchell), and Eupatagus gardnerae (Cooke), and is differentiated from its cogener Echinolampas appendiculata (Emmons) by its proportionately narrower and higher test, with a prominent keel that runs from posterior of the apical to the posterior margin.

Recent excavations in the Martin Marietta Quarry, Castle Hayne North Carolina have provided abundant exposures of bryozoan biomicrudite of sequence three of the Castle Hayne Limestone. A trio of new echinoid species have been collected from this material, each representing a new genus for the unit. Collections include specimens of the genus Brissus—the first record of the genus in the Eocene of the region, as well as a new species of Schizaster, and a regular urchin that is not attributable to any genus of regular urchin recorded from the fauna, which includes the genera: Cidaris, Phyllacanthus, Coelopleurus and Dixieus.