PBDB Collection

Twin Buttes (Eocene of the United States)

Where: Sioux County, Nebraska (42.4° N, 103.8° W)

• Paleocoordinates: 48.1° N, 86.8° W (Wright 2013)

• coordinate based on political unit

When: Big Cottonwood Creek Member (Chadron Formation), Chadronian (37.2 - 33.9 Ma)

• member assignment based on LaGarry pers. commun. 19 May 2005

Environment/lithology: terrestrial

Primary reference: G. E. Ostrander. 1985. Correlation of the early Oligocene (Chadronian) in northwestern Nebraska. Dakoterra 2(2):205-231 [J. Alroy/J. Alroy/P. Holroyd]more details

PaleoDB collection 17033: authorized by John Alroy, entered by John Alroy on 18.02.1993

Creative Commons license: CC0 (CC0)

Taxonomic list

• apparently includes UNSM Sx-29
NE 1/4 sec 36 T33N R53W
"Cylindrodon fontis" is probably misidentified, see discussion of this species by Emry and Korth 1996a

Show authors, comments, and common names

Mammalia
Carnivora - Canidae	Hesperocyon sp. Hesperocyon sp. Scott 1890 canid
Artiodactyla - Protoceratidae	Pseudoprotoceras longinaris Pseudoprotoceras longinaris Cook 1934 protoceratid
Artiodactyla - Leptomerycidae	Leptomeryx sp. Leptomeryx sp. Leidy 1853 ruminant
Perissodactyla - Brontotheriidae	Brontotheriidae indet. Brontotheriidae indet. Marsh 1873 brontothere
Perissodactyla - Equidae	Equidae indet.¹ Equidae indet.¹ Gray 1821 horse
Perissodactyla - Hyracodontidae	"Hyracodon doddi n. sp." = Hyracodon nebraskensis "Hyracodon doddi n. sp." = Hyracodon nebraskensis Leidy 1850 odd-toed ungulate from UNSM Sx-29
Soricomorpha - Soricidae	Domnina gradata Domnina gradata Cope 1873 shrew
Soricomorpha - Apternodontidae	Apternodus sp.² Apternodus sp.² Matthew 1903 placental
Soricomorpha - Micropternodontidae	Micropternodus montrosensis Micropternodus montrosensis Ostrander 1983 placental
Soricomorpha - Oligoryctidae	Oligoryctes cameronensis Oligoryctes cameronensis Hough 1956 placental
Soricomorpha - Geolabididae	Centetodon chadronensis Centetodon chadronensis Lillegraven et al. 1981 placental
Rodentia - Cylindrodontidae	Pseudocylindrodon neglectus, Cylindrodon nebraskensis¹ Pseudocylindrodon neglectus Burke 1935 rodent Cylindrodon nebraskensis¹ Hough and Alf 1956 rodent
Rodentia - Castoridae	Agnotocastor sp. Agnotocastor sp. Stirton 1935 beaver
Rodentia - Eomyidae	Eomyidae indet., "Yoderimys burkei" = Zemiodontomys burkei, Aulolithomys bounites, "Paradjidaumo trilophus" = Adjidaumo trilophus, Adjidaumo minimus, Adjidaumo minutus Eomyidae indet. Winge 1887 rodent "Yoderimys burkei" = Zemiodontomys burkei Black 1965 rodent Aulolithomys bounites Black 1965 rodent "Paradjidaumo trilophus" = Adjidaumo trilophus Cope 1873 rodent Adjidaumo minimus Matthew 1903 rodent Adjidaumo minutus Cope 1873 rodent
Rodentia - Ischyromyidae	Ischyromys sp. Ischyromys sp. Leidy 1856 rodent
Rodentia - Aplodontidae	Prosciurus vetustus Prosciurus vetustus Matthew 1903 mountain beaver
Rodentia - Sciuridae	Sciuridae indet.¹ Sciuridae indet.¹ Gray 1821 squirrel
Lagomorpha - Leporidae	Palaeolagus temnodon Palaeolagus temnodon Douglass 1902 rabbit
Chiroptera -	Chiroptera indet. Chiroptera indet. Blumenbach 1779 bat a bat
Cimolesta - Apatemyidae	Sinclairella dakotensis Sinclairella dakotensis Jepsen 1934 eutherian
Tribosphenida - Herpetotheriidae	"Peratherium fugax" = Herpetotherium fugax "Peratherium fugax" = Herpetotherium fugax Cope 1873 marsupial
Reptilia
Squamata -	Peltosaurus sp. Peltosaurus sp. Cope 1873 squamates
Squamata - Anguidae	Glyptosaurus sp. Glyptosaurus sp. Marsh 1871 squamates

¹Alroy 2002; ²Asher et al. 2002