Pinna comancheana Cragin, 1894

Remarks

• Collector:    Keith Minor
• Formation:  Fredericksburg Group, Goodland Limestone
• Location:     Tarrant County, Texas

General Info

Synonyms (older names and misidentifications in the literature)

• 1894 Pinna comancheana Cragin
• 1924 Pinna comancheana Cragin; Twenhofel
• 1928 Pinna comancheana Cragin; Adkins
• 1960 Pinna comancheana Cragin; Perkins
• 2002 Pinna comancheana Cragin; Akers & Akers

Stratigraphic Occurrence

• Fredericksburg Group, Comanche Peak Formation
• Fredericksburg Group, Goodland Formation, Mary's Creek Member
• Tucumcari Formation of New Mexico
• Kiowa Formation of Kansas
• Surprisingly, we haven't found any reports of P. comancheana Cragin from the Duck Creek Formation although the clam is found from Kdc equivalents in New Mexico and Kansas.  We have personally found Pinna's in the Duck Creek, but all of them are too weathered to make a call on the species.

Age

• Pinna comancheana Cragin ranges from the Oxytropidoceras (Oxytropidoceras) carbonarium Gabb Zone to the Eopachydiscus marcianus (Shumard) Zone, late Middle Albian to early Late Albian Stage (~103–101 mya).

Geographic Occurrence (by no means an all-inclusive list)

• Kiowa County, KS
• Quay County, NM
• Tarrant County, TX

Remarks

         For identification and descriptions, see:

• Adkins, W. S.  1928.  Handbook of Texas Cretaceous Fossils.  University of Texas Bulletin 2838, 90; plate 18, fig. 6.