Ostrea alifera var. pediformis Craigin

Taxonomy

Oyster

Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Ostreoida
Family: Ostridae
Genus: Ostrea
Species: Ostrea alifera var. pediformis
Author Citation Craigin 1893

Geological Time Scale

Eon: Phanerozoic
Era: Mesozoic
Period: Cretaceous
Sub Period: None
Epoch: Late
International Age: Turonian

Stratigraphy

Eagle Ford Group
Arcadia Park Formation

Provenance

Collector: Me
Acquired by: Field Collection

Dimensions

Length: 44 mm
Width: 22 mm
Thickness: 9 mm

Location

Post Oak Creek south side of Sherman, Texas
Grayson County
Texas
United States

• arcadia park formation
• cretaceous
• eagle ford
• ostrea alifera
• ostrea alifera var. pediformis
• oyster
• post oak creek
• sherman

Comments

This is a Cretaceous oyster that I found in Post Oak Creek in Sherman, Texas. The oyster has traces of a yellowish calcite-cemented sandstone found in the upper part of the Arcadia Park Formation of the Eagle Ford Group.

 

"Pediformis" in the name, Ostrea alifera var. pediformis, means foot-shaped or pediform because the oyster looks like a foot or boot.

 

In Hill 1898, the author

eliminated the Ostrea alifera Cragin, and Ostrea alifera var. pediformis Cragin names because he considered them to be Ostrea lugubris Conrad. I disagree with Hill's decision because my oyster is larger than most O. lugubris (now Cameleolopha lugubris) and lacks an attachment scar characteristic of O. lugubris. My oyster may be a genus Cameleolopha since both Cameleolopha bellaplicata and Cameleolopha lugubris occur nearby. Unless new information can be found, my oyster should be called: Ostrea alifera variety pediformis Craigin.

 

For more information and drawings of Ostrea alifera and Ostrea alifera variety pediformis Craigin see:

 

Cragin,  F. W. 1893. "A Contribution to the Invertebrate Paleontology of the Texas Cretaceous", Austin, Texas, B.C. Jones & Co., State printers.

 

Hill, Robert T. & T. W. Vaughan. 1898. The Lower Cretaceous *Grypheas* of the Texas region. U. S. Geological Survey, Bulletin 151: 139 pp.