Journal of Paleontology; February 2005; v. 79; no. 2;
p. 366-377; DOI: 10.1666/0022-3360(2005)079<0366:CAGUIN>2.0.CO;2
© 2005 Paleontological Society
CISURALIAN AMMONOID GENUS URALOCERAS IN NORTH AMERICA
TAMRA A. SCHIAPPA1,
NIKKI T. HEMMESCH2,
CLAUDE SPINOSA2 and
W. W. NASSICHUK3
1 Department of Geography, Geology and the Environment, Slippery Rock University, Pennsylvania 16057, <tamra.schiappa{at}sru.edu>;
2 Department of Geosciences, Boise State University, Idaho 83725, <nthemmesch{at}hotmail.com>, <cspinosa{at}boisestate.edu>;
3 Geological Survey of Canada, Institute of Sedimentary and Petroleum Geology, Calgary, <wnassichuk{at}gsc.emr.ca>
In North America, the ammonoid Uraloceras Ruzhentsev occurs in Cisuralian (Lower Permian) strata of the northern Yukon Territory, eastern Alaska, Ellesmere Island, southern British Columbia, and Nevada. From Sakmarian to Kungurian, species of Uraloceras occupied a narrow belt in the Northern Hemisphere (Boreal paleogeographical realm) that extended from the northern and northwestern margin of the Pangaean supercontinent southward to regions of present-day Siberia, the Ural Mountains, as well as Nei Monggol and Tibet. In the Yukon Territory, Nevada, Nei Monggol, and possibly Tibet, the association of Uraloceras with typically equatorial perrinitid ammonoids may represent a transition from "Boreal" occurrences in high latitudes to "Tethyan" of lower latitudes. Uraloceras nevadense n. sp. is described herein from Nevada and eastern Alaska.
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