Cook Ranch: Orellan, Montana

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia - Lagomorpha - Leporidae
Megalagus cf. turgidus (Cope 1873)
Palaeolagus haydeni Leidy 1856
see also Wood 1937
"Palaeolagus" cf. burkei Schlaikjer 1935
Mammalia - Rodentia - Cricetidae
Scottimus viduus Korth 1981
    = Willeumys viduus Korth 1981
Korth 2019
Wilsoneumys sp. Martin 1980
said to be new
    = Wilsoneumys focarius n. sp. Korth 2019
Korth 2019
Eumys cf. parvidens Wood 1937
Eumys aff. brachyodus Wood 1937
Eumys cf. elegans Leidy 1856
"and/or E. cricetodontoides"
    = Eumys cf. cricetodontoides White 1954
Korth 2019
Scottimus sp. Wood 1937
Mammalia - Rodentia - Cylindrodontidae
Pseudocylindrodon sp. Burke 1935
said to be new
? Sespemys sp. Wilson 1934
said to be new
Mammalia - Rodentia - Aplodontidae
Pelycomys sp. Galbreath 1953
    = Ninamys annectens Korth 1989
Korth 2019
Prosciurus cf. parvus Korth 1989
    = Disallomys intermedius
Korth 2019
? Prosciurus sp. (Matthew 1903)
said to be new
    = Brachygaulus nicholsi Korth and Tabrum 2011
Korth 2019
Brachygaulus nicholsi n. sp. Korth and Tabrum 2011
Korth and Tabrum 2011
see Korth and Tabrum 2011
Prosciurinae indet. Wilson 1949
said to be a new genus and species
Mammalia - Rodentia - Eomyidae
Paradjidaumo sp. Burke 1934
said to be new
    = Paradjidaumo cf. trilophus Cope 1873
Korth 2019
recombined as Adjidaumo trilophus
Adjidaumo minimus (Matthew 1903)
Metadjidaumo sp. Setoguchi 1978
said to be new
    = Metadjidaumo woodi n. sp. Korth 2019
Korth 2019
Mammalia - Rodentia - Heliscomyidae
Heliscomys gregoryi Wood 1933
see also Wood 1933: "H. new species" of Wood 1937
Heliscomys cf. mcgrewi Korth 1989
    = Megaheliscomys mcgrewi Korth 1989
Korth 2019
Mammalia - Rodentia - Castoridae
Agnotocastor sp. Stirton 1935
    = Agnotocastor cf. praetereadens Stirton 1935
Korth 2019
Mammalia - Rodentia - Ischyromyidae
Ischyromys sp. Leidy 1856
Mammalia - Carnivora - Canidae
Hesperocyon gregarius (Cope 1873)
see also Wood 1937
Mammalia - Carnivora - Palaeogalidae
Palaeogale sectoria (Gervais 1848)
Mammalia - Perissodactyla - Equidae
Mesohippus sp. Marsh 1875
see also Wood 1937
Mammalia - Perissodactyla - Rhinocerotidae
Subhyracodon sp. Wood 1927
    = Subhyracodon occidentalis Leidy 1850
Prothero 2005
Mammalia - Perissodactyla - Hyracodontidae
? Hyracodon sp. Leidy 1856
see also Wood 1937
Mammalia - Anthracotheriidae
? Elomeryx sp. Marsh 1894
Mammalia - Merycoidodontidae
? Miniochoerus sp. Schultz and Falkenbach 1956
Merycoidodon cf. culbertsoni (Leidy 1848)
original and current combination Merycoidodon culbertsonii
Mammalia - Leptomerycidae
? Hendryomeryx sp. Black 1978
Leptomeryx sp. Leidy 1853
said to be new
Leptomeryx aff. evansi Leidy 1853
see also Wood 1937
Mammalia - Camelidae
Poebrotherium sp. Leidy 1847
Mammalia - Erinaceidae
Ocajila cf. makpiyahe Macdonald 1963
Mammalia - Oligoryctidae
Oligoryctes cf. altitalonidus (Clark 1936)
Mammalia - Proscalopidae
Oligoscalops sp. Reed 1961
said to be new
Mammalia - Talpidae
Talpidae indet. (Fischer de Waldheim 1817)
two species, said to be new
Mammalia - Soricidae
Domnina aff. gradata Cope 1873
Mammalia - Chiroptera - Vespertilionidae
Vespertilionidae indet. Gray 1821
a bat
Mammalia
Herpetotherium fugax (Cope 1873)
includes "H. sp." of Korth 1994; "Didelphidectes pumilis" of Hough 1961; and probably "Peratherium" of Wood 1937
Copedelphys cf. stevensoni (Cope 1873)
Nanodelphys hunti (Cope 1873)
recombined as Nanodelphys huntii
see common names

Geography
Country:United States State/province:Montana County:Beaverhead
Coordinates: 45.0° North, 112.8° West (view map)
Paleocoordinates:46.6° North, 104.7° West
Basis of coordinate:based on political unit
Geographic resolution:small collection
Time
Period:Paleogene Epoch:Oligocene
Stage:Rupelian 10 m.y. bin:Cenozoic 4
*Period:Tertiary
Key time interval:Orellan
Age range of interval:33.90000 - 31.80000 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Sage Creek Member:upper
Local section:SageC Local bed:7
Local order:bottom to top
Lithology and environment
Environment:terrestrial indet.
Taphonomy
Modes of preservation:body
Collection methods and comments
Reason for describing collection:biostratigraphic analysis
Taxonomic list comments:originally described by Wood 1937
from two collections 10 m apart according to Wood, which matches discussion of Tabrum et al. 1996
stratigraphic nomenclature supersedes that of Hough 1955
Metadata
Also known as:MV 7721, MV 7722, MV 7723, MV 7726, MV 7734, MV 7745
Database number:17090
Authorizer:J. Alroy, C. Boyd, J. Marcot Enterer:J. Alroy, J. Marcot, C. Boyd
Modifier:J. Alroy Research group:vertebrate
Created:1993-02-18 00:00:00 Last modified:2006-09-13 00:27:33
Access level:the public Released:1993-02-18 00:00:00
Creative Commons license:CC BY
Reference information

Primary reference:
3359. A. R. Tabrum, D. R. Prothero, and D. Garcia. 1996. Magnetostratigraphy and biostratigraphy of the Eocene-Oligocene transition, southwestern Montana. In D. R. Prothero and R. J. Emry (eds.), The Terrestrial Eocene-Oligocene Transition in North America 278-311 [J. Alroy/J. Alroy/J. Alroy]

Secondary references:

71288 W. W. Korth. 2019. Rodents (Mammalia) from the early Oligocene (Orellan) Cook Ranch local fauna of southwestern Montana. Annals of Carnegie Museum 85(3):223-248 [C. Boyd/C. Boyd]
64659 W. W. Korth and A. R. Tabrum. 2011. A new aplodontoid rodent (Mammalia) from the early Oligocene (Orellan) of Montana and a suggested origin for the family Mylagaulidae. Annals of Carnegie Museum 80(1):67-81 [G. Liggett/G. Liggett]
51726 D. R. Prothero. 2005. The Evolution of North American Rhinoceroses. 1-218 [J. Marcot/J. Marcot]