Opal (UW 1-67) (Eocene of the United States)

Where: Lincoln County, Wyoming (41.8° N, 110.3° W: paleocoordinates 45.8° N, 96.5° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

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

• bed-level stratigraphic resolution

Environment/lithology: fluvial; tuff

• white tuff bed... typically varies between 3 to 8 feet in thickness... very fine-grained and highly altered and in places interbedded in the tuff are laminated siltstones

Reposited in the UW

Primary reference: P. O. McGrew and R. Sullivan. 1971. The stratigraphy and paleontology of Bridger A. Contributions to Geology, University of Wyoming 9(2):66-85 [J. Alroy/J. Alroy/J. Marcot]more details

PaleoDB collection 16355: authorized by John Alroy, entered by John Alroy on 21.09.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

• the following records appear to be from the Opal area, but exact localities are unclear and all five species occur in the new UM collections of Gunnell 1998c: Anaptomorphus westi Gunnell 1995a: UW V-65003, 65004, 67034 Patriofelis ulta Gazin 1957: "20-25 miles east of Kemmerer, Wyo." Bathyopsis "middleswarti" Wheeler 1961: type Stylinodon mirus Schoch 1986 Palaeosyops fontinalis Osborn 1929: type, from Big Sandy Creek near the Green River
Mammalia
 Cimolesta - Esthonychidae
Trogosus latidens Marsh 1874 tillodont
 Primates - Microsyopidae
Microsyops elegans Marsh 1871 primate
 Primates - Notharctidae
Notharctus robinsoni2 Gingerich 1979 primate
 Rodentia - Sciuravidae
Sciuravus nitidus Marsh 1871 rodent
Sciuravus bridgeri Wilson 1938 rodent
called into question by Gunnell 1998c
 Rodentia - Ischyromyidae
Paramys cf. delicatus Leidy 1871 rodent
Leptotomus parvus Wood 1959 rodent
 Perissodactyla - Hyrachyidae
Hyrachyus sp.1 Leidy 1871 odd-toed ungulate
 Perissodactyla - Equidae
Orohippus pumilus Marsh 1871 horse
 Macroscelidea - Amphilemuridae
Scenopagus priscus Marsh 1872 elephant shrew