Where: Weld County, Colorado (40.8° N, 104.2° W: paleocoordinates 41.4° N, 101.0° W)
• coordinate based on political unit
• small collection-level geographic resolution
When: Pawnee Creek Formation, Barstovian (16.3 - 12.5 Ma)
• upper part of formation sensu stricto, and there is a "radioisotopic" (Ar-Ar?) date of 14.4 Ma for an ash in the middle level of the formation: Woodburne 1996a
•this date apparently is an average of the dates of 14.5 +/- 0.09 and 14.3 +/- 0.02 Ma (Ar/Ar) given by Dold and Prothero 2003 for the "middle part of the section"
Environment/lithology: terrestrial
Primary reference: R. H. Tedford, T. Galusha, M. F. Skinner, B. E. Taylor, R. W. Fields, J. R. Macdonald, J. M. Rensberger, S. D. Webb, and D. P. Whistler. 1987. Faunal succession and biochronology of the Arikareean through Hemphillian interval (late Oligocene through earliest Pliocene epochs) in North America. In M. O. Woodburne (ed.), Cenozoic Mammals of North America: Geochronology and Biostratigraphy 153-210 [J. Alroy/J. Alroy/P. Wagner]more details
Purpose of describing collection: biostratigraphic analysis
PaleoDB collection 18203: authorized by John Alroy, entered by John Alroy on 05.08.1992, edited by Jonathan Marcot
Creative Commons license: CC BY (attribution)
Taxonomic list
•"Barbouromeryx (Bouromeryx) pawniensis" Frick 1937: type, "two miles W. of Mastodon Quarry"; also from "Section 8"
Mammalia | |
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Gomphotheriidae indet. Hay 1922 gomphothere may include type of "Rhynchotherium rectidens" of Osborn 1923 from "near Pawnee Buttes, Middle Miocene of Colorado"
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Tomarctus brevirostris8 Cope 1873 bone-crushing dog Cedar Creek; Horse Quarry; probably includes "Aelurodon sp."
Microtomarctus conferta8 Matthew 1918 bone-crushing dog Horse Quarry; also at "Martin Canyon... Cedar Creek, horizon E" (said to be the same age and in the same county)
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"Merychyus cf. medius" = Ustatochoerus medius1
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"Dromomeryx pawniensis n. sp." = Dromomeryx borealis2
"Dromomeryx pawniensis n. sp." = Dromomeryx borealis2 Cope 1877 ruminant Horse Quarry; Mastodon Quarry; "east of camp"; "Section 8"; "Lower Mastodon Quarry"; also postcrania from "6 miles N.E. of Pawnee Buttes"
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Paracosoryx sp. Frick 1937 pronghorn | |
Megahippus sp.7, "Merychippus sphenodus" = Cormohipparion sphenodus9, Pliohippus mirabilis3, "Protohippus sejunctus" = Merychippus sejunctus3
"Merychippus sphenodus" = Cormohipparion sphenodus9 Cope 1889 hipparionine horse sensu stricto; additional material is from Dark Cap Quarry = West Quarry, in unit just below H & M Quarry
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