Scaphites of the "nodosus group" from the Upper Cretaceous (Campanian) of the Western Interior of North America. (Bulletin of the American Museum of Natural History, no. 342)

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dc.contributor.author Landman, Neil H.
dc.contributor.author Kennedy, W. J. (William James)
dc.contributor.author Cobban, William Aubrey, 1916-
dc.contributor.author Larson, Neal L.
dc.date.accessioned 2010-09-22T13:05:26Z
dc.date.available 2010-09-22T13:05:26Z
dc.date.issued 2010
dc.identifier.uri http://hdl.handle.net/2246/6083
dc.description 242 p. : ill., maps ; 26 cm. "Issued September 21, 2010." en
dc.description.abstract Scaphitid ammonites (scaphites) are common in the Upper Cretaceous Pierre Shale and Bearpaw Shale of the Western Interior of North America. We redescribe Hoploscaphites nodosus (Owen, 1852) and H. brevis (Meek, 1876) from the Baculites compressus–B. cuneatus zones of the upper Campanian. The types of both of these species were collected in the mid-19th century in what was then called Nebraska Territory, and included parts of present-day South Dakota, North Dakota, and Montana. Based on our present knowledge of the distribution of these species, the type material was probably collected from the B. compressus–B. cuneatus zones in the Pierre Shale at Sage Creek, a tributary of the Cheyenne River, Pennington County, South Dakota. Traditionally, the more robust, more coarsely ornamented scaphites (comprising the "nodosus group") from the Pierre Shale and Bearpaw Shale were assigned to Jeletzkytes Riccardi, 1983, and the more slender, more finely ornamented scaphites were assigned to Hoploscaphites Nowak, 1911. However, our large collections of these scaphites from the Baculites compressus– B. cuneatus zones reveal a complete intergradation between the two morphological extremes, and for many specimens, the choice of genus is arbitrary. In addition, our studies of other biostratigraphic zones in the Pierre Shale and Bearpaw Shale reveal that cooccurring species of these two "genera" share more in common with each other than they do with congeneric species from other horizons. Furthermore, contrary to earlier assumptions, Jeletkytes is not endemic to the Western Interior Basin of North America and occurs, for example, in the U.S. Atlantic Coastal Plain and Europe. We thus provisionally treat Jeletzkytes as a junior subjective synonym of Hoploscaphites. This expanded definition of Hoploscaphites is consistent with present-day concepts of other scaphitid genera such as Discoscaphites Meek, 1876, and Trachyscaphites Cobban and Scott, 1964... en
dc.format.extent 82830695 bytes
dc.format.extent 1127586 bytes
dc.format.mimetype application/pdf
dc.format.mimetype application/pdf
dc.language.iso en_US en
dc.publisher American Museum of Natural History. en
dc.relation.ispartofseries Bulletin of the American Museum of Natural History, no. 342. en
dc.subject Hoploscaphites nodosus. en
dc.subject Hoploscaphites brevis. en
dc.subject Scaphites. en
dc.subject Ammonoidea. en
dc.subject West (U.S.) en
dc.title Scaphites of the "nodosus group" from the Upper Cretaceous (Campanian) of the Western Interior of North America. (Bulletin of the American Museum of Natural History, no. 342) en

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  • Bulletin of the American Museum of Natural History
    The Bulletin, published continuously since 1881, consists of longer monographic volumes in the field of natural sciences relating to zoology, paleontology, and geology. Current numbers are published at irregular intervals. The Bulletin was originally a place to publish short papers, while longer works appeared in the Memoirs. However, in the 1920s, the Memoirs ceased and the Bulletin series began publishing longer papers. A new series, the Novitates , published short papers describing new forms.

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