Santonian (Late Cretaceous) Cephalopods

Santonian age cephalopods occur in the Emery Sandstone Member of the Mancos Shale. The Garley Canyon Beds and the Lower Emery Beds south from Huntington are where the fossils pictured below were found. These rocks were deposited in the Sevier Foreland Basin.

References: Reeside, J. B., Jr., 1927, The Cephalopods of the Eagle Sandstone and Related Formations in the Western Interior of the United States, U.S.G.S. Professional Paper 151; Cobban, W. A., 1951, Scaphitoid Cephalopods of the Colorado Group, U.S.G.S. Professional Paper 239; Cobban, W. A., 1976, Ammonite Record from the Mancos Shale of the Castle Valley-Price-Woodside Area, East-Central Utah, B.Y.U. Geology Studies Vol.22, Pt.3

See the Emery Sandstone here

A large Placenticeras pseudocostatum
(Johnson) 1903, at the outcrop

Clioscaphites vermiformis
(Meek & Hayden) 1862


Baculites codyensis Reeside 1927

Texanites ?texanus (Roemer) 1852
217mm dia.

Placenticeras pseudocostatum (Johnson) 1903, ?male dimorph
formerly refered to P. guadalupae (Roemer) 1952
511mm diameter

Placenticeras pseudocostatum (Johnson) 1903, ?female dimorph
formerly refered to P. planum Hyatt 1903
530mm diameter

Typical fossil cephalopods from the Lower Emery Sandstone and Garley Canyon Beds
Placenticeras pseudocostatum (Johnson) 1903, is the common ammonite
Clioscaphites vermiformis (Meek & Hayden) 1862, Top Center, Eutrephoceras alcesense Reeside 1927, Bottom Center
Baculites codyensis Reeside 1927, Lower Left.

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