This bivalve fossil was found in Monroeville, Monroe County, Alabama in the Gosport Sand Formation. It existed in the Eocene Epoch of the Paleogene Period. The fossil appears to be a
Venericardia planicosta (Lamarck 1801). It is extra nice in that both halves are present. I still need to clean this fossil. Thanks to Herb & Pam for the fossil.
Identification based on plate 167 figure 22 of
Index Fossils of North America (Shimer & Shrock, 1944).