Hopper Section ( of the United States)

Also known as Haystack Valley Member

Where: Wheeler County, Oregon (44.8° N, 119.7° W: paleocoordinates 44.5° N, 110.8° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Haystack Valley Member (John Day Formation), early Late Arikareean (30.8 - 20.4 Ma)

• member-level stratigraphic resolution

Environment/lithology: terrestrial; gray, green tuff and gray, green siltstone

• gray-green ribbed tuff; gray-green siltstone to very fine sandstone; also celadonite bench (siltstone), yellow-green tuffaceous claystone, and gray massive tuff with well-developed paleosol

Size class: macrofossils

Reposited in the UCMP

Primary reference: R. M. Hunt, Jr. and E. Stepleton. 2004. Geology and paleontology of the upper John Day beds, John Day river valley, Oregon: lithostratigraphic and biochronologic revision in the Haystack Valley and Kimberly areas (Kimberly and Mt. Misery quadrangles). Bulletin of the American Museum of Natural History 282:1-90 [J. Alroy/J. Alroy/J. Alroy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 36766: authorized by John Alroy, entered by John Alroy on 14.02.2004, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

Mammalia
 Carnivora - Amphicyonidae
Temnocyoninae indet. Hunt 1998 bear-dog
 Artiodactyla - Tayassuidae
Cynorca sp. Cope 1867 peccary
 Artiodactyla - Merycoidodontidae
Paroreodon sp. Thorpe 1921 oreodont
 Artiodactyla - Hypertragulidae
cf. Nanotragulus sp. Lull 1922 ruminant