Inoceramus (Volviceramus) grandis (Conrad, 1875)

Remarks

• Collector:    Prof. Norm King, University of Southern Indiana

• Formation:  Niobrara Group, Smoky Hill Chalk

• Location:     Western Kansas

• Here's a classic Inoceramid from the Kansas Chalks.
• The external surface is encrusted by the oyster Pseudoperna congesta (Conrad).
• In Norm's image of the interior (left image) you can see part of the exterior edge of the shell that has been folded in on itself (right side in the image).

General Info

Synonyms (older names and misidentifications in the literature)

• "Snowshoe Clam"

• 1875 Inoceramus (Haploscapha) grandis Conrad

• 1928 Inoceramus (Haploscapha) grandis Conrad; Adkins

• 1977 Volviceramus grandis (Conrad); Kauffman

• 1977 Volviceramus grandis (Conrad); Hattin and Cobban

• 1982 Inoceramus (Volviceramus) grandis Conrad; Hattin

• 2002 Volviceramus grandis (Conrad); Akers & Akers

Stratigraphic Occurrence

• Niobrara Group, lower Smoky Hill Chalk of western Kansas

• Basal Austin Group of central Texas (suggests Atco Limestone)

• Terlingua Group, Boquillas Limestone of Trans-Pecos, Texas

Age

• Inoceramus (Volviceramus) grandis (Conrad) occurs in the Scaphites ventricosus Meek & Hayden zone, upper Coniacian Stage (~87–86 mya).

Geographic Occurrence

• Brewster County, TX

• Gove County, KS

• Travis County, TX

• Trego County, KS

Remarks

         For identification, see:

• Hattin, D. E.  1982.  Stratigraphy and Depositional Environment of Smoky Hill Chalk Member, Niobrara Chalk (Upper Cretaceous) of the Type Area, Western Kansas.  Kansas University Geological Survey Bulletin 225.1–108 (great images!).