Observations on the Cenomanian (upper Cretaceous) ammonite Calycoceras (Calycoceras) obrieni Young, 1957 from Arizona and New Mexico
By: by William A. Cobban and W. James Kennedy.
Contributors: Kennedy, W. J.
Series: U.S. Geological Survey bulletin -- 1881-C; Shorter contributions to paleontology and stratigraphy
Publisher: U.S. G.P.O.
Published: 1990
Place of publication: [Washington]
Language: eng
Number of pages: 11
Subjects: Paleontology -- Cretaceous.; Paleontology -- West (U.S.) -- Cretaceous.; Ammonoidea -- Arizona.; Ammonoidea -- New Mexico.; Ammonoidea -- West (U.S.)
Notes: "Description of an upper Cenomanian marker ammonite from the southern part of the western interior of the United States."

Includes bibliographical references (p. 4).