Pholas pectorosa Conrad, 1852

Remarks

• Collection:   Mississippi Museum of Natural Science.  Photos by Curator George Phillips.  Thanks!

• Formation:  Navarro Group Equivalent, Prairie Bluff Formation

• Location:     Chickasaw County, Mississippi

General Info

Synonyms (other reports in the literature)

• 1834 Pholas cithara Morton
• 1852 Pholas ? pectorosa Conrad
• 1852 Pholas ? pectorosa Conrad; Conrad
• 1861 Pholas cithara Morton; Gabb (in part)
• 1864 Pholas cithara Morton; Meek
• 1868 Clavipholas cithara (Morton); Conrad
• 1876 Martesia cithara (Morton); Gabb (in part)
• 1886 Pholas cithara Morton; Whitfield (in part)
• 1905 Pholas pectorosa Conrad; Johnson
• 1907 Pholas cithara Morton; Weller (in part)
• 1916 Pholas pectorosa Conrad; Gardner
• 1916 Pholas pectorosa Conrad; Clark
• 1941 Pholas pectorosa Conrad; Stephenson
• 2002 Pholas ? pectorosa Conrad; Akers & Akers

         *Conrad's type has historically been accepted to take precedence over Morton's P. cithara since Morton's specimen is lost and his figure of the clam is indeterminable.

Stratigraphic Occurrence

• Navarro Group, Corsicana Marl of north Texas
• Navarro Group Equivalent, Prairie Bluff Formation of Mississippi
• Monmouth Group, Tinton Formation of New Jersey
• Matawan Group, Wenonah Formation of New Jersey
• Matawan Group, Merchantville Clay of New Jersey
• Matawan Group, Woodbury Clay of New Jersey

Age

• Pholas pectorosa Conrad is a relatively long-ranging boring clam, ranging from the Scaphites hippocrepis (Dekay) form III Cobban Zone to the Sphenodiscus pleurisepta (Conrad) Zone, Earliest Campanian to very Late Maastrichtian (~81–66 mya).

Geographic Occurrence (not an all-inclusive list)

• Chickasaw County, MS
• Hunt County, TX
• Monmouth County, New Jersey
• Middlesex County, New Jersey

Remarks

         For identification and descriptions, see:

• Clark, W. B.  1916.  The Upper Cretaceous Deposits of Maryland.  Text and Plates.  Maryland Geological Survey.  Baltimore:  Johns Hopkins Press, 724–726; plate XLV, fig. 1.
• Weller, S.  1907.  A Report on the Cretaceous Paleontology of New Jersey, Based Upon the Stratigraphic Studies of George N. Knapp.  Geological Survey of New Jersey Paleontology Series 4, 651–651; plate LXXIV, fig. 7.
• Whitfield, R. P.  1886.  Brachiopoda and Lamellibranchiata of the Raritan Clays and Greensand Marls of New Jersey.  United States Geological Survey Monograph 9, 187–188; plate XXV, fig's 14–16.

         Compare with:

• Morton, S. G.  1834.  Synopsis of the Organic Remains of the Cretaceous Group of the United States.  Illustrated by Nineteen Plates, to Which is Added an Appendix Containing a Tabular View of the Tertiary Fossils Discovered in America.  Philadelphia:  Key and Biddle, 68, plate 9, fig. 10.