Oysters in the genus Crassostrea and their predecessors are present in fossil record to at least 50 million years ago. These species have evolved to be long lived, highly fecund, and settle gregariously to create essential three-dimensional habitat in estuaries worldwide. The underlying shell base must be maintained by accretion rates higher than the combined impacts of sedimentation, harvest, and sea level rise for reefs to persist. Fossil oysters provide a unique opportunity to understand reef dynamics during periods of rapid sea level rise. This project describes the distribution of fossil oyster shell and demographics on the mid-Atlantic continental shelf at depths ranging from 27-64 m (90-210 ft). Fossil oyster shells were found at 47 of 66 dredge survey locations. Fossil shell lengths ranged from 53 to 223 mm (Fig. 1). Collected fossil can be used to estimate reef accretion rates and carbonate production in the distant past and facilitate comparison with extant populations.