NEW RECORDS OF COMATULID CRINOIDS FROM THE EOCENE OF SOUTHWESTERN GEORGIA

Comatulid crinoids have only a limited stratigraphic record in the Tertiary of the southeastern U.S., based upon relatively few published reports of the fossils through the last 150 years. However, crinoid specimens continue to be recovered from Coastal Plain limestones, and papers and abstracts published in the last twenty years indicate these fossils are present in states from Louisiana through North Carolina. Oyen and Perrault (1997) summarized the distribution of crinoids known in this region, including those collected from Georgia. At that time, the only identified comatulid species from Georgia was Himerometra bassleri, collected from the Dry Branch Formation (Upper Eocene) in Burke County and limestone spoil likely from the Ocala Limestone (Upper Eocene) of Dougherty County.

Herein we report additional crinoids have been collected (by J. Summerour) from outcrops of the Ocmulgee Formation (Upper Eocene) in Lee County of southwestern Georgia. The specimens include disarticulated centrodorsals and brachials of H. bassleri, plus one or more additional taxa. We tentatively identify several of these centrodorsals to be a species of Poliometra, while other fossils remain unidentified. If these identifications are correct, the fossils are the first records of Poliometra in Georgia, and add to the potential fossil distribution of the genus (thus far, only reported elsewhere from Alabama). Modern species of Poliometra are present in ocean depth ranges from 20-1960 m, and the limestones from which the fossils were collected likely were deposited in depths at the shallower end of this range. However, further comparison must be done with additional described comatulid taxa before our identifications can be fully confirmed. All comatulid crinoid fossils from Georgia noted herein are part of the Invertebrate Paleontology collection of the Florida Museum of Natural History in Gainesville, Florida.