"From 40 to 55 million years ago" . . . . . . . . . . . . . . . . "Stratigraphy and zonation of the Ocala group"@en . "Stratigraphy and zonation of the Ocala group" . . "Regional studies of the Ocala limestone include all calcareous sediments of Jackson age that occur east of Tombigbee River. Also included is a comprehensive study of the Foraminifera of the Ocala group, and a detailed study of the Ostracoda contained in this group."@en . . . . . . . . . "Geology Florida." . . . .