Clarno Nut Beds: Middle Eocene, Oregon

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia - Oxyaenidae
UCMP V-78127
Mammalia - Perissodactyla - Equidae
Alroy 2002
UCMP V-4203, 78127:
Mammalia - Perissodactyla - Hyrachyidae
Stirton 1944
UCMP V-4203 (Clarno Bridge)
Hanson 1996
also at UCMP V-65513, 78127
Mammalia - Perissodactyla - Brontotheriidae
said to be new; UCMP V-65513
Mihlbachler and Samuels 2016
Reptilia - Testudines
Reptilia
Pristichampsus sp. Gervais 1853
    = Boverisuchus sp. Kuhn 1938
Brochu 2013
re-identification by reference to site not specimens p524
see common names

Geography
Country:United States State/province:Oregon County:Wheeler
Coordinates: 44.9° North, 120.2° West (view map)
Paleocoordinates:51.2° North, 96.4° West (Wright 2013)
Basis of coordinate:based on political unit
Geographic resolution:small collection
Time
Period: Paleogene Epoch: Eocene
10 m.y. bin: Cenozoic 2-3
*Period:Tertiary *Local age/stage:Bridgerian
Key time interval: Middle Eocene
Age range of interval: 48.07 - 37.71 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Clarno Member:Unit B
Local section:Clarn Local bed:1
Local order:bottom to top
Stratigraphy comments: said to be Bridgerian

The Nut beds have yielded ages between 42 and 44Ma (Manchester 1994; Bestland et al. 1999) placing the locality within the Uintan NALMA. However, several authors have noted Bridgerian fauna from the Clarno vertebrate localities (Stirton 1944; Hanson 1996). Mihlbachler and Samuels 2016 suggest that referring to the Clarno vertebrate localities in terms of NALMA ages is problematic, as Oregan biostratigraphy during the Eocene and Miocene is in need of greater study and the localities share taxa considered characteristic of multiple land mammal ages.
Lithology and environment
Primary lithology: conglomerate
Secondary lithology: sandstone
Environment:terrestrial indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Museum repositories:UCMP
Taxonomic list comments:see also Fremd et al. 1994
NISP 28
maintained as a single list because UCMP V-4203 is not discussed and UCMP V-65513 is a general locality that does include key specimens
about 100 m below Hancock Quarry
best date is 48.32 +/- 0.11 Ma (SCLF AA on plagioclase); a second AA determination of 43.8 +/- 0.31 Ma apparently includes multiple crystal populations, and two FT dates on zircon have broad errors that overlap with the 48.32 Ma date
see also Krishtalka et al. 1987
Metadata
Also known as:UCMP V-4203, V-62403, V-65513, V-78127
Database number:16202
Authorizer:J. Alroy, P. Holroyd Enterer:J. Alroy, P. Holroyd
Modifier:G. Varnham Research group:vertebrate
Created:1995-03-26 00:00:00 Last modified:2025-02-22 15:12:02
Access level:the public Released:1995-03-26 00:00:00
Creative Commons license:CC0
Reference information

Primary reference:
1782. C. B. Hanson. 1996. Stratigraphy and vertebrate faunas of the Bridgerian-Duchesnean Clarno Formation, north-central Oregon. In D. R. Prothero and R. J. Emry (eds.), The Terrestrial Eocene-Oligocene Transition in North America 206-239 [J. Alroy/J. Alroy/J. Marcot]

Secondary references:

6294 J. Alroy. 2002. Synonymies and reidentifications of North American fossil mammals. [J. Alroy/J. Alroy/M. Kouvari]
48280 C. A. Brochu. 2013. Phylogenetic relationships of Palaeogene ziphodont eusuchians and the status of Pristichampsus Gervais, 1853. Earth and Environmental Science Transactions of the Royal Society of Edinburgh 103:1-30 [P. Mannion/P. Mannion]
61063 M. C. Mihlbachler and J. X. Samuels. 2016. A small-bodied species of Brontotheriidae from the middle Eocene Nut Beds of the Clarno Formation, John Day Basin, Oregon. Journal of Paleontology 90(6):1233-1244 [P. Holroyd/P. Holroyd]
38795% 46000R. A. Stirton. 1944. A rhinoceros tooth from the Clarno Eocene of Oregon. Journal of Paleontology 18(3):265-267 [J. Alroy/J. Alroy/W. Clyde]