Pycnodonte convexa (Say, 1820)

Remarks

• Collector:    Keith Minor

• Formation:  Monmouth Group, Navesink Formation

• Location:     Monmouth County, NJ

General Info

Synonyms (older names and misidentifications in the literature)

• 1820 Gryphaea convexa Say, 1820
• 1830 Gryphaea convexa Say; Morton
• 1940 Gryphaea convexa Say; Stephenson and Monroe
• 1958 Gryphaea convexa Say; Richards
• 1982 Pycnodonte convexa Say; Offeman et al.

Stratigraphic Occurrence

• Upper Taylor Group, Marlbrook Marl of North Texas
• Navarro Group, Neylandville Marl of North Texas
• Montana Grp, Pierre Fm, "Unnamed Shale Mbr" of SD
• Upper Matawan Group, Marshalltown Formation of NJ
• Monmouth Group, Mount Laurel Formation of NJ and DE
• Monmouth Group, Navesink Formation of New Jersey and Delaware
• Monmouth Group, Severn Formation of Maryland
• Rancocas Group, Hornerstown Formation of NJ (Tertiary, Paleocene)
• Black Creek Formation of North Carolina
• Peedee Formation of North Carolina
• Peedee Formation of South Carolina
• Selma Group, Demopolis Chalk of MS and AL
• Ripley Formation, Coon Creek Tongue of TN
• Ripley Formation of MS and AL

Age

• Pycnodonte convexa (Say) occurs in Upper Cretaceous (Upper Campanian and Maastrichtian) and Lower Tertiary (Paleocene) rocks in the United States (~78-62 mya).

Geographic Occurrence (not an all-inclusive list)

• Alcorn County, MS
• AL (no county given
• Bladen County, NC
• GA (no county given)
• Gloucester County, NJ
• MD (no county given)
• Monmouth County, NJ
• New Castle County, DE
• Ocean County, NJ
• SC (no county given)
• Salem County, NJ
• Southwestern South Dakota (no county given)
• McNairy County, TN
• TX (no county given)

Remarks

         For identification, descriptions, and ranges, see:

• Meek, F. B.  Hayden, F. V.  1876.  A Report on the Invertebrate Cretaceous and Tertiary Fossils of the Upper Missouri Country.  United States Geological Survey of the Territories 9.
• Richards, H. G. 1958. The Cretaceous Fossils of New Jersey. New Jersey Geological Survey Bulletin 61 (1), 114–115.
• 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.  1882–1883.  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, 273–410.

         The best photo for identification (complete specimen with both valves) can be found in:

• Stephenson, L. W.; Monroe, W. H.  1940.  The Upper Cretaceous Deposits [Mississippi].  Mississippi State Geological Survey Bulletin 40, Plate 5, fig's 8–10.