Companion Quarry (Miocene of the United States)

Also known as UNSM Sx-128

Where: Sioux County, Nebraska (42.2° N, 103.7° W: paleocoordinates 42.9° N, 99.8° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Sheep Creek Formation, Late/Upper Hemingfordian (20.4 - 16.0 Ma)

• said to be late Hemingfordian and "within the lower part of the Sheep Creek Formation"; exact level within formation indeterminable

Environment/lithology: fluvial; sandstone and conglomerate

• "fluvial, cross-bedded sand and gravel"

Size classes: macrofossils, mesofossils

Reposited in the UNSM

Collection methods: bulk, salvage, sieve,

• "abundant microvertebrate remains" were salvaged and 680 kg of concentrate including "microvertebrates" was dry-screened; collection size only pertains to small mammals

Primary reference: B. E. Bailey. 2004. Biostratigraphy and biochronology of early Arikareean through late Hemingfordian small mammal faunas from the Nebraska Panhandle and adjacent areas. Paludicola 4(3):81-113 [J. Alroy/J. Alroy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 17889: authorized by John Alroy, entered by John Alroy on 13.10.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

• Herpetotherium and other, unidentified taxa are "an artifact of reworking from the underlying Harrison Formation" and are excluded from the list

•fauna also includes "fish, common with low diversity; both amphibians and reptiles common with moderate diversity (isolated alligator teeth were the most abundant elements); birds, rare"

 Rodentia - Sciuridae
Protospermophilus kelloggi Black 1963 squirrel
Miospermophilus wyomingensis Black 1963 squirrel
 Rodentia - Geomyidae
Phelosaccomys sp.2 Korth and Reynolds 1994 pocket gopher
said to be new by Bailey 2004
 Rodentia - Heteromyidae
Cupidinimus sp. Wood 1935 rodent
Harrymys magnus2 Wood 1932 rodent
Proheteromys sp. Wood 1932 rodent
Peridiomys rusticus Matthew 1924 rodent
Schizodontomys sp. Rensberger 1973 rodent
 Rodentia - Castoridae
Monosaulax sp. Stirton 1935 beaver
 Rodentia - Mylagaulidae
Galbreathia novellus Matthew 1924 rodent
Alphagaulus vetus Matthew 1924 rodent
 Rodentia - Zapodidae
Schaubeumys sabrae Black 1958 jumping mouse
 Lagomorpha - Leporidae
Hypolagus sp. Dice 1917 rabbit
 Lagomorpha - Ochotonidae
Oreolagus nebrascensis McGrew 1941 pika
 Lipotyphla - Erinaceidae
Brachyerix sp. Matthew 1933 hedgehog
 Lipotyphla - Talpidae
Scalopoides isodens Wilson 1960 mole
 Perissodactyla - Equidae
Merychippus primus3 Osborn 1918 horse
 Tribosphenida - Soricidae
cf. Adeloblarina sp. Repenning 1967 red-toothed shrew
"five genera"; includes a blarinine and another soricid: Bailey 1999
Limnoecus sp. Stirton 1930 shrew
said to be new
 Tribosphenida - Proscalopidae
Mesoscalops scopelotemos Reed 1960 placental
 Chiroptera - Vespertilionidae
cf. Myotis sp. Kaup 1829 vesper bat
a bat
 Ungulata - Antilocapridae
Paracosoryx wilsoni1 Frick 1937 pronghorn