Inoceramus comancheanus Cragin, 1895

Remarks

• Strat and locale information on clam 1:  Base of the Washita Group, Lower Limestone Member of the Duck Creek Formation, Cooke County, TX (collection of Keith Minor).
• Clam 1 is not the best specimen, but the rarity of finding a semi-complete one alone qualifies it for our website.
• Clam 2 shows the usual preservation, as an internal mold.

General Info

Synonyms (older names and misidentifications in the literature)

• 1895 Inoceramus comancheanus Cragin
• 1920 Inoceramus comancheanus Cragin; Adkins and Winton
• 1922 Inoceramus comancheanus Cragin; Reeside
• 1925 Inoceramus comancheanus Cragin; Winton
• 1928 Inoceramus comancehanus Cragin; Adkins
• 1947 Inoceramus comancheanus Cragin; Shimer and Shrock
• 1960 Inoceramus comancheanus Cragin; Perkins
• 1982 Inoceramus comancheanus Cragin; Offeman et al.
• 1989 Inoceramus comancheanus Cragin; Finsley
• 2002 Inoceramus comancheanus Cragin; Akers and Akers

Stratigraphic Occurrence

• Lower Washita Group, Boracho Formation, Levinson Member of Trans-Pecos Texas
• Basal Washita Group, Duck Creek Formation, Lower Limestone Formation North Texas
• Basal Washita Group, Lower Part of the Georgetown Formation of Central Texas
• Basal Washita Group, Caddo Formation of Oklahoma
• Top of the Fredericksburg Group, Kiamichi Formation of North Texas
• Upper Fredericksburg Group, Comanche Peak Limestone of North Central Texas

Age

• Inoceramus comancheanus Cragin occurs at the base of the Eopachydiscus marcianus (Shumard) zone and ranges down into the Oxytropidoceras (Oxytropidoceras) carbonarium (Gabb) zone, late Middle Albian to early Late Albian (~103–101 mya).

Geographic Occurrence (not an all-inclusive list)

• Cooke County, TX
• Denton County, TX
• Grayson County, TX
• Hudspeth County, TX
• Marshall County, OK
• Tarrant County, TX
• Wise County, TX

Remarks

         For identification, descriptions, and ranges, see:

• Adkins, W. S.  1927 (1928).  Handbook of Texas Cretaceous Fossils.  University of Texas Bulletin 2838.
• Adkins, W. S.; Winton, W. M.  1920.  Paleontological Correlation of the Fredericksburg and Washita Formations in North Texas.  University of Texas Bulletin 1945, 1–128.