Duncan Ranch (Lower) (Eocene of the United States)

Where: Fremont County, Wyoming (43.2° N, 108.2° W: paleocoordinates 47.0° N, 94.0° W)

• coordinate based on political unit

When: Aycross Formation, Bridgerian (50.3 - 46.2 Ma)

Environment/lithology: terrestrial

Primary reference: T. M. Bown. 1982. Geology, Paleontology, and Correlation of Eocene Volcaniclastic Rocks, Southeast Absaroka Range, Hot Springs County, Wyoming. United States Geological Survey Professional Paper 1201-A:A1-A75 [J. Alroy/J. Alroy/J. Marcot]more details

PaleoDB collection 16212: authorized by John Alroy, entered by John Alroy on 18.02.1993

Creative Commons license: CC BY (attribution)

Taxonomic list

• "more than a hundred feet lower" than upper Duncan Ranch
type area of Aycross Fm. (see Love 1939)
early Bridgerian (Bridger A?)
 Perissodactyla - Brontotheriidae
Palaeosyops cf. paludosus Leidy 1870 brontothere
Eotitanops borealis Cope 1880 brontothere
called into question by Stucky 1984c
 Perissodactyla -
Desmatotherium intermedius Osborn et al. 1878 odd-toed ungulate
 Perissodactyla - Isectolophidae
Isectolophidae indet. Peterson 1919 odd-toed ungulate
 Oxyaenodonta - Oxyaenidae
Patriofelis sp. Leidy 1870