White River (Basal Uinta B1) (Eocene of the United States)

Where: Uintah County, Utah (40.2° N, 109.9° W: paleocoordinates 43.0° N, 98.9° W)

• coordinate based on political unit

When: Wagonhound Member (Uinta Formation), Uintan (46.2 - 39.7 Ma)

Environment/lithology: terrestrial

Primary reference: O. A. Peterson. 1914. A Small Titanothere From The Lower Uinta Beds. Annals of Carnegie Museum 9(3):53-57 [J. Alroy/J. Alroy/J. Marcot]more details

PaleoDB collection 16655: authorized by John Alroy, entered by John Alroy on 21.09.1998

Creative Commons license: CC BY (attribution)

Taxonomic list

• paleomagnetic stratigraphy of Prothero 1996a for his two sections in the central and eastern part of the basin is internally consistent, but radioisotopic dating is not adequate to correlate it to the GMPTS: 1) "Class 1" K-Ar dates of Mauger 1977 for the Wavy Tuff in the underlying Green River (44.8 = 46.0, 44.7 = 45.9 Ma) are of uncertain polarity; 2) "Class 1" K-Ar date of Mauger 1977 for the "Saline facies" of Dane 1954 (41.7 = 42.8 +/- 1.0 Ma) cannot be related lithostratigraphically or biostratigraphically to the two major, fossiliferous sections 3) Lapoint Tuff date of Prothero and Swisher 1992 (39.74 +/- 0.07 Ma) is higher in the section than Prothero's highest samples taking the first and last as bracketing dates, Prothero's sections may begin in C21n or C20n and end in C19n or C18n; this conclusion is matched by McCarroll et al. 1996b
I assume that most B1 specimens are not from the basal part of the zone because Prothero and Swisher 1992 claim that very few specimens are - however, they seem unaware of several Osborn titanothere records
Mammalia
 Perissodactyla - Hyrachyidae
Hyrachyus eximius2 Leidy 1871 odd-toed ungulate
listed as "Uinta B1" by Prothero 1996a
 Perissodactyla - Brontotheriidae
"Dolichorhinus sp." = Sphenocoelus1, Metarhinus parvus1
"Dolichorhinus sp." = Sphenocoelus1 Osborn 1895 brontothere
Metarhinus parvus1 brontothere