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Late Pliocene and early Pleistocene rodents from the northern Borchers Badlands (Meade County, Kansas), with comments on the Blancan-Irvingtonian boundary in the Meade Basin

Published online by Cambridge University Press:  20 May 2016

Robert A. Martin
Affiliation:
Department of Biological Sciences, Murray State University, Murray, Kentucky 42071,
Ryan T. Hurt
Affiliation:
Department of Biological Sciences, Murray State University, Murray, Kentucky 42071,
James G. Honey
Affiliation:
Geology Section, University of Colorado, Boulder 80309-0315
Pablo Peláez-Campomanes
Affiliation:
Department of Paleobiology, National Museum of Natural History, C.S.I.C., José Gutierrez Abascal 2, Madrid 28006, Spain

Abstract

New fossiliferous localities in the Borchers Badlands of southwestern Kansas add to our knowledge of rodent community change across the Plio-Pleistocene and Blancan-Irvingtonian boundaries. We report fossil rodents from ten local faunas in the Badlands that range stratigraphically from beneath the Huckleberry Ridge ash (2.10 Ma [million years ago]) to a level just beneath the Cerro Toledo B ash (1.23–1.47 Ma). The late Blancan Borchers local fauna (l.f.), includes the Meade Basin highest stratigraphic datum (HSD) for the following taxa that characterize or are found in earlier Blancan faunas: Alilepus, Geomys quinni, Sigmodon minor, and Geochelone. Borchers currently also has the HSDs for Reithrodontomys pratincola and Ondatra zibethicus lidahoensis, but the prior temporal distribution of these taxa in the Meade Basin is unknown. The stratigraphically lowest Pleistocene (Irvingtonian) l.f. in the Badlands, Nash 72, includes the lowest stratigraphic datum (LSD) for Cynomys, Reithrodontomys moorei, Microtus, and Mictomys kansasensis, all of which are found above Nash 72 and beneath the Cerro Toledo B ash. Prodipodomys is last seen at Nash 72, and Sigmodon curtisi is first encountered at Short Haul, a locality slightly younger than Nash 72. A preliminary hypothesis of age based on stratigraphic position places the Nash 72 l.f. at about 1.80 Ma, suggesting that this fauna and the genus Microtus may characterize both the Plio-Pleistocene and Blancan-Irvingtonian boundaries in the Borchers Badlands.

Type
Research Article
Copyright
Copyright © The Paleontological Society

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