Paper No. 76-31
Presentation Time: 9:00 AM-5:30 PM
SYSTEMATICS AND ENVIRONMENTAL DISTRIBUTION OF THE BATOCRINIDAE (CLASS CRINOIDEA) IN THE FORT PAYNE FORMATION (EARLY VISéAN, MISSISSIPPIAN) OF KENTUCKY, TENNESSEE, AND ALABAMA
The Batocrinidae is a dominant clade of camerate crinoids in North America during the Mississippian, where representatives occurred in a range of carbonate and siliciclastic settings. Batocrinids are especially common in the Fort Payne Formation of Kentucky, Tennessee, and Alabama, where more than 2,000 specimens have been recovered that represents nearly one quarter of the Fort Payne crinoids. The Fort Payne Formation is a complex of siliciclastic and carbonate facies, including two types of autochthonous carbonate mounds (wackestone buildups and crinoidal packstone buildups). Thirteen species assigned to six genera were documented from the Fort Payne Formation, which includes one new species; and more than ten species are designated as junior synonyms. Fort Payne batocrinid genera include Abatocrinus, Alloprosallocrinus, Eretmocrinus, Macrocrinus, Magnuscrinus, and Uperocrinus. With consideration of the entire crinoid assemblages, Alloprosallocrinus conicus is a dominant crinoid on wackestone buildups, and Eretmocrinus magnificus is a dominant crinoid on crinoidal packstone buildups. Within the Fort Payne as a whole, batocrinids are more abundant in the crinoidal packstone facies and in allochthonous carbonate facies. Their occurrence in transported facies reflects the well sutured batocrinid calyx, which is more taphonomically resistant than many camerates and other crinoid clades. Batocrinids are relatively rare on the wackestone buildups and in autochthonous siliciclastic facies.