Inoceramus perplexus Whitfield, 1877

Remarks

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

• Formation:  Upper Mancos Shale (between the Juana Lopez Member and overlying Niobrara Group, Fort Hays Limestone)

• Location:     Delta and Las Animas Counties, CO

Remarks

• Collector:  Howie Cohn
• Formation:  Carlile Shale, Turner Sandy Member
• Location:  Fall River County, SD

General Info

Synonyms (older names in the literature)

• 1834–1840 Inoceramus undulatus Mantell; Goldfuss

• 1877 Inoceramus perplexus Whitfield

• 1880 Inoceramus perplexus Whitfield; Whitfield

• 1893 Inoceramus perplexus Whitfield; Boyle

• 1894 Inoceramus fragilis Hall & Meek; Stanton

• 1898 Inoceramus perplexus Whitfield; Logan

• 1912 Inoceramus costellatus Woods (in part)

• 1930 Inoceramus costellatus Woods; Fiege

• 1964? Inoceramus aff. I. perplexus Whitfield; Scott & Cobban (in part)

• 1967 Inoceramus vancouverensis Shumard; Tröger

• 1967 Inoceramus vancouverensis parvus Tröger

• 1977 Inoceramus (Inoceramus) perplexus Whitfield; Kauffman

• 1978 Inoceramus (Inoceramus) perplexus Whitfield; Kauffman et al.

• 1978 Inoceramus (Inoceramus) n. sp. aff. 'I. costellatus Woods'; Kauffman

• 1978 Inoceramus uwajimensis Yehara; Kauffman

• 1984 Inoceramus perplexus Whitfield Cobban

• 1982 Inoceramus costellatus costellatus Woods; Keller

• 1992 Inoceramus costellatus Woods; Walaszczyk

• 2000 Inoceramus perplexus Whitfield; Walaszczyk & Cobban

Stratigraphic Occurrence

• Upper Mancos Shale of Colorado and New Mexico

• Carlile Formation, Sage Breaks Shale Member of South Dakota

• Carlile Formation, Turner Sandy Member of South Dakota

• Frontier Formation, Wall Creek Sandstone Member of Wyoming

Age

• Inoceramus perplexus Whitfield is a bivalve marker for the very Late Turonian Stage (~ 89 mya) in the U. S. Western Interior.

Geographic Occurrence (not an all-inclusive list)

• Albany County, WY

• Butte County, SD

• Carbon County, WY

• Cibola County, NM

• Delta County, CO

• Fall County, SD

• Las Animas County, CO

Remarks

         For identification, descriptions, and range see:

• Kauffman, E. G.  1977.  “Illustrated Guide to Biostratigraphically Important Macrofossils, Western Interior Basin, U. S. A.”.  In:  Kauffman, E. G., ed.  Field Guide:  North American Paleontological Convention II.  Cretaceous Facies, Faunas, and Paleoenvironments Across the Western Interior Basin.  The Mountain Geologist 14 (3-4), plate 8, fig's 6 and 15.
• Kauffman, E. G.; Sageman, B. B.; Kirkland, J. I.; Elder, W. P.; Harries, P. J.; Villamil, T. 1993.  "Molluscan Biostratigraphy of the Cretaceous Western Interior Basin, North America".  In:  Caldwell, W. G. E.; Kauffman, E. G., eds. Geological Association of Canada Special Paper 39, 414.
• Walaszczyk, I.; Cobban, W. A.  2000.  Inoceramid Faunas and Biostratigraphy of the Upper Turonian-Lower Coniacian of the Western Interior of the United States.  Palaeontological Association, Special Papers in Palaeontology 64, 32−36, plate 5, fig's 1–9; plate 6, fig's 1−2; and plate 9, fig 7.