Haystack Member (Miocene of the United States)

Where: Wheeler County, Oregon (44.9° N, 120.2° W: paleocoordinates 44.7° N, 114.2° W)

• coordinate based on political unit

When: John Day Formation, Hemingfordian (20.4 - 16.0 Ma)

• member-level stratigraphic resolution

Environment/lithology: terrestrial

Primary reference: T. Fremd. 1994. John Day Basin paleontology field trip guide and road log: Society of Vertebrate Paleontology. John Day Fossil Beds National Monument 94-1 [J. Alroy/J. Alroy/M. Uhen]more details

PaleoDB collection 17925: authorized by John Alroy, entered by John Alroy on 30.04.1994, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

• although the Haystack Valley is in Wheeler County, some of this material is probably from Grant County
overlies "? ATR Tuff" dated at 22.6 Ma (AA)
said to be 20 Ma or younger based on biochronology, i.e., early Hemingfordian
unclassified
  -
Mammalia
 Rodentia - Geomyidae
Entoptychus individens Rensberger 1971 pocket gopher
Entoptychus planifrons1 Cope 1878 pocket gopher
 Rodentia - Heteromyidae
Schizodontomys greeni Rensberger 1973 rodent
 Rodentia - Allomyidae
Rudiomys mcgrewi Rensberger 1983 rodent
"prob. Haystack"
 Rodentia - Mylagaulidae
Mylagaulidae indet.1 Cope 1881 rodent
 Lagomorpha - Leporidae
Archaeolagus cf. macrocephalus Matthew 1907 rabbit
 Perissodactyla - Tapiridae
Nexuotapirus robustus1 Sinclair 1901 tapir
 Carnivora - Amphicyonidae
Paradaphoenus sp. Wortman and Matthew 1899 bear-dog
presumably includes type of "Daphoenus minimus" from the "Scenic Member" (Hough 1948)
Daphoenus socialis1 Thorpe 1922 bear-dog
Daphoenodon sp.1 Peterson 1909 bear-dog
 Ungulata - Merycoidodontidae
Merychyus arenarum Cope 1884 oreodont
Merycoides longiceps1 Douglass 1907 oreodont
Merycochoerus matthewi Loomis 1924 oreodont
Hypsiops breviceps Douglass 1907 oreodont
 Ungulata - Entelodontidae
Archaeotherium caninus2 Troxell 1920 even-toed ungulate
UCMP 415: specimen number appears in appendix. Taxonomic assignment from UCMP catalog website
 Ungulata - Camelidae
Camelidae indet. Gray 1821 camel