Exogyra costata Say, 1820

Remarks

• Collector:    Keith Minor

• Formation:  Monmouth Group, Navesink Formation

• Location:     Monmouth County, New Jersey

General Info

Synonyms (older names and misidentifications in the literature)

         Amazingly, this is one of the few oysters that have escaped taxonomic revision over the last 180 years!

• 1820 Exogyra costata Say

• 1834 Exogyra tortosa Morton

• 1884 Exogyra costata Say; White

• 1886 Exogyra costata Say, Whitfield

• 1906 Exogyra costata Say; Böse

• 1907 Exogyra costata Say; Weller

• 1914 Exogyra costata Say; Stephenson

• 1916 Exogyra costata Say; Gardner

• 1923 Exogyra costata Say; Stephenson

• 1924 Exogyra costata Say; Deussen

• 1926 Exogyra costata Say; Wade

• 1928 Exogyra costata Say; Adkins

• 1954 Exogyra costata Say; Groot, Organist, and Richards

• 1958 Exogyra costata Say; Richards

Stratigraphic Occurrence

         Where Campanian/Maastrichtian rocks occur along the Gulf and Atlantic Coast Exogyra

         costata Say occurs in abundance. Happy hunting!

• Cardenas Formation of Central Mexico

• Lower Matawan Group, Woodbury Formation (??) of New Jersey

• Basal Monmouth Group, Mount Laurel Formation of NJ, DE, and MD

• Lower Monmouth Group, Navesink Formation of NJ, DE, and MD

• Upper Monmouth Group, Red Bank Formation of New Jersey

• Top of the Monmouth Group, Tinton Formation of New Jersey

• Navarro Group, Escondido Formation of Central Texas

• Navarro Group, Kemp Formation of North–Central Texas

• Navarro Group, Neylandville Formation of North Texas

• Navarro Group, Corsicana Formation of North–Central Texas

• Navarro Group, Saratoga Formation of South–West Arkansas

• Navarro Group, Nacatoch Formation of South–West Arkansas

• Navarro Group, Arkadelphia Formation of South–West Arkansas

• Upper Selma Group, Demopolis Chalk of Mississippi and Tennessee

• Ripley Formation of Mississippi

• Prairie Bluff Formation of Mississippi

• Owl Creek Formation of Mississippi

• Peedee Formation of North and South Carolina

Age

• Exogyra costata Say ranges from about the Didymoceras nebrascense (Meek and Hayden) zone to about the Baculites clinolobatus Eliaszone (lower Upper Campanian to lower Maastrichtian, ~76–69 mya)

• If the report of Exogyra costata Say from the Woodbury Clay is valid, then this species first occurs in the Lower Campanian Stage.

Geographic Occurrence (not an all-inclusive list)

• Alcorn County, MS

• Barbour County, AL

• Bladen County, NC

• Bowie County, TX

• Chickasaw County, MS

• Clay County, MS

• Dallas County, AL

• Darlington County, SC

• Hempstead County, AR

• Guadelupe County, TX

• Kaufman County, TX

• Kemper County, MS

• Kent County, MD

• Lee County, MS

• Lowndes County, AL

• Marengo County, AL

• Marion County, GA

• McNairy County, TN

• Monmouth County, NJ

• Maverick County, TX

• Medina County, TX

• New Castle County, DE

• New Hanover County, NC

• Noxube County, MS

• Oktibbeha County, MS

• Pike County, AL

• Pitt County, NC

• Pontotoc County, MS

• Prentice County, MS

• San Luis Potosi, Mexico

• Stewart County, GA

• Sumter County, AL

• Tamaulipas, Mexico

• Travis County, TX

• Union County, TX

• Uvalde County, TX

Remarks

         For identification and descriptions, see:

• Adkins, W. S. 1928. Handbook of Texas Cretaceous Fossils. Bureau of Economic Geology, University of Texas Bulletin 2838.
• Carter, J. G.; Gallagher, P. E.; Valone, R. E.; Rossbach, T. J.; Gensel, P. G.; Wheeler, W. H.; Whitman, D. 1988. Fossil Collecting in North Carolina. North Carolina Geological Survey Bulletin 89.
• Richards, H. G. 1958. The Cretaceous Fossils of New Jersey. New Jersey Geological Survey Bulletin 61 (2), 117–118.
• Stephenson, L. W. 1914. Cretaceous Deposits of the Eastern Gulf Region and Species of Exogyra from the Eastern Gulf Region and the Carolinas. United States Geological Survey Professional Paper 81.
• White, C. A. 1884. A Review of the Fossil Ostreidae of North America; and a Comparison of the Fossil with the Living Forms. United States Geological Survey, Fourth Annual Report.