Clarno Nut Beds (Eocene of the United States)

Also known as UCMP V-4203, V-62403, V-65513, V-78127

Where: Wheeler County, Oregon (44.9° N, 120.2° W: paleocoordinates 46.4° N, 105.2° W)

• coordinate based on political unit

• small collection-level geographic resolution

When: Unit B Member (Clarno Formation), Middle Eocene (47.8 - 37.7 Ma)

• 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.

Environment/lithology: terrestrial; conglomerate and sandstone

Size class: macrofossils

Reposited in the UCMP

Primary reference: 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]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 16202: authorized by John Alroy, entered by John Alroy on 26.03.1995, edited by Patricia Holroyd

Creative Commons license: CC BY (attribution)

Taxonomic list

• 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
Reptilia
 Crocodylia - Planocraniidae
Boverisuchus sp.2 Kuhn 1938 crocodilian
 Testudines - Pantestudinidae
Hadrianus sp. Cope 1872 turtle
Mammalia
 Perissodactyla - Hyrachyidae
Hyrachyus eximius Leidy 1871 odd-toed ungulate
UCMP V-4203 (Clarno Bridge)
 Perissodactyla - Brontotheriidae
Xylotitan cenosus n. gen. n. sp.3
Xylotitan cenosus n. gen. n. sp.3 Mihlbachler and Samuels 2016 brontothere
said to be new; UCMP V-65513
 Perissodactyla - Equidae
Xenicohippus craspedotum1 Cope 1880 horse
 Creodonta - Oxyaenidae
Patriofelis ferox Marsh 1872 creodont
UCMP V-78127