Bitterroot Ranch (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 16135: authorized by John Alroy, entered by John Alroy on 18.02.1993

Creative Commons license: CC BY (attribution)

Taxonomic list

• type area of Aycross Fm.
in the East Fork area, but correlation with Duncan Ranch levels is unclear
Mammalia
 Tribosphenida - Phenacodontidae
Phenacodontidae indet. Cope 1881 condylarth
 Perissodactyla - Brontotheriidae
cf. Palaeosyops sp. Leidy 1870 brontothere
"probably not P. fontinalis"; this appears to be the specimen of P. fontinalis mentioned by Stucky 1984c
 Perissodactyla - Hyrachyidae
Hyrachyus cf. eximius Leidy 1871 odd-toed ungulate