Where: Nebraska (42.8° N, 103.6° W: paleocoordinates 44.0° N, 95.2° W)
• coordinate based on nearby landmark
• local area-level geographic resolution
When: Big Cottonwood Creek Member (Chadron Formation), Late/Upper Chadronian to Late/Upper Chadronian (37.2 - 33.3 Ma)
• "All of the ant mounds sampled in this study rest upon rocks of the Big Cottonwood Creek Member. Detailed study of fossils previously collected in and around Toadstool Geological Park a few miles north of the present study area placed the stratigraphic position of the faunal transition between the Chadronian and Orellan biochrons at two meters above the UPW (±5 meters: Zanazzi et al., 2009). That same study determined that the late Chadronian (Ch4) to middle Chadronian (Ch3) subdivision transision occurred 18 meters below the UPW (±2 meters: Zanazzi et al., 2009), which is below the stratigraphic positions of all the ant mounds sampled in this study. Thus, the stratigraphic distribution of these ant mounds spans rocks that may preserve fossils deposited across the Chadronian-Orellan boundary, with the oldest fossils contributed from a late Chadronian fauna." (Korth et al. 2022)
• group of beds-level stratigraphic resolution
Environment/lithology: terrestrial; lithology not reported
Size classes: macrofossils, mesofossils
Collection methods: Repository: Museum of Geology at the South Dakota School of Mines and Technology, Rapid City, South Dakota, USA
Primary reference: W. W. Korth, C. A. Boyd, J. J. Person and D. Anderson. 2022. Fossil mammals from ant mounds situated on exposures of the Big Cottonwood Creek Member of the Chadron Formation (latest Eocene - Early Oligocene), Sioux County, Nebraska. Paludicola 13(4):191-344 [B. Allen/B. Allen]more details
Purpose of describing collection: general faunal/floral analysis
PaleoDB collection 230806: authorized by Bethany Allen, entered by Bethany Allen on 21.07.2023
Creative Commons license: CC BY (attribution)
Taxonomic list
Mammalia | |
Copedelphys stevensoni Cope 1873 marsupial
Herpetotherium fugax Cope 1873 marsupial
Herpetotherium valens Lambe 1908 marsupial | |
"Nanodelphys hunti" = Nanodelphys huntii
"Nanodelphys hunti" = Nanodelphys huntii Cope 1873 marsupial | |
Sinclairella dakotensis Jepsen 1934 eutherian
Apatemys sp. Marsh 1872 eutherian | |
? Vespertilionidae indet. Gray 1821 vesper bat | |
Ankylodon cf. progressus Galbreath 1953 elephant shrew | |
Omomyidae indet. Gazin 1958 tarsier | |
| |
Haplomys galbreathi Tedrow and Korth 1997 rodent | |
Altasciurus sp., Altasciurus clausulus, Altasciurus relictus, Altasciurus albiclivus, Ansomys cyanotephrus, Protansomys gulottai n. gen. n. sp., Campestrallomys sp., Campestrallomys siouxensis, Oropyctis sp., Oropyctis cf. pediasius, Pseudallomys sp., Costepeiromys attasorus n. gen. n. sp., Pelycomys sp.
Altasciurus sp. Korth and Tabrum 2017 mountain beaver
Altasciurus clausulus Korth 2009 mountain beaver
Altasciurus relictus Cope 1873 mountain beaver
Altasciurus albiclivus Korth 1994 mountain beaver
Ansomys cyanotephrus Korth 2007 mountain beaver
Protansomys gulottai n. gen. n. sp. Korth et al. 2022 mountain beaver SDSM 152447 (holotype), left dentary fragment with m1 and m2
Campestrallomys sp. Korth 1989 mountain beaver
Campestrallomys siouxensis Korth 1989 mountain beaver
Oropyctis sp. Korth 1989 mountain beaver
Oropyctis cf. pediasius Korth 1989 mountain beaver
Pseudallomys sp. Korth 1992 mountain beaver
Costepeiromys attasorus n. gen. n. sp. Korth et al. 2022 mountain beaver SDSM 155705 (holotype), left m2
Pelycomys sp. Galbreath 1953 mountain beaver | |
Protosciurus mengi, Hesperopetes sp., Douglassciurus bjorki, Oligospermophilus douglassi, Cedromus modicus
Protosciurus mengi Black 1963 squirrel
Hesperopetes sp. Emry and Korth 2007 squirrel
Douglassciurus bjorki Korth 2014 squirrel
Oligospermophilus douglassi Korth 1981 squirrel
Cedromus modicus Korth et al. 2022 squirrel | |
Scottimus exiguus, Scottimus ambiguus, Scottimus lophatus, Eumys elegans, Willeumys viduus, Wilsoneumys planidens
Scottimus exiguus Wood 1937 rodent
Scottimus ambiguus Korth 1981 rodent
Scottimus lophatus Wood 1937 rodent
Eumys elegans Leidy 1856 rodent
Willeumys viduus Korth 1981 rodent
Wilsoneumys planidens Wilson 1949 rodent | |
Ischyromys brevidens n. sp.
| |
Cylindrodontidae indet. Miller and Gidley 1918 rodent
Cylindrodon nebraskensis Hough and Alf 1956 rodent
Siouxlindrodon sullivani n. gen. n. sp. Korth et al. 2022 rodent SDSM 155559, 155576 (syntypes), left M1 or M1, left m1 or m2
| |
Eutypomys cf. hibernodus Korth 2000 rodent | |
Aulolithomys vexilliames, Aulolithomys cf. bounites, Metanoiamys paradoxus, Adjidaumo minimus, Adjidaumo intermedius, Yoderimys massarae n. sp., Litoyoderimys grossus n. sp., Centimanomys major, Paradjidaumo cf. validus, Paradjidaumo patriciae n. sp.
Aulolithomys vexilliames Korth and Emry 1997 rodent
Aulolithomys cf. bounites Black 1965 rodent
Metanoiamys paradoxus Emry and Korth 2012 rodent
Adjidaumo minimus Matthew 1903 rodent
Adjidaumo intermedius Korth 1989 rodent
Yoderimys massarae n. sp. Korth et al. 2022 rodent SDSM 154961, 154967 (syntypes), right M1, left p4
Litoyoderimys grossus n. sp. Korth et al. 2022 rodent SDSM 154969, 154970 (syntypes), right p4, right m1 or m2
Centimanomys major Galbreath 1955 rodent
Paradjidaumo cf. validus Korth 1980 rodent
Paradjidaumo patriciae n. sp. Korth et al. 2022 rodent SDSM 150984 (holotype), right dentary with partial i1, p4-m3
| |
Megaheliscomys mcgrewi Korth 1989 rodent
Heliscomys sp. Cope 1873 rodent
Heliscomys hatcheri Wood 1935 rodent
Heliscomys vetus Cope 1873 rodent | |
Tenudomys basilaris Korth 1989 pocket gopher | |
Diplolophus insolens Troxell 1923 rodent
Epeiromys sp. Korth 1989 rodent | |
Kirkomys miriamae n. sp. Korth et al. 2022 rodent SDSM 151069 (holotype), left dentary fragment with p4
Ecclesimus tenuiceps Galbreath 1948 rodent | |
Pipestoneomys pattersoni Alf 1962 rodent | |
Stibarus cf. obtusilobus Cope 1873 even-toed ungulate | |
Hypisodus minimus Cope 1873 ruminant | |
? Leptomeryx sp. Leidy 1853 ruminant
Leptomeryx cf. exilis Cook 1934 ruminant | |
Ursoidea indet. Fischer de Waldheim 1817 carnivoran | |
Subparictis dakotensis Clark 1936 carnivoran | |
Palaeogale cf. minuta Gervais 1848 carnivoran | |
Hesperocyon gregarius Cope 1873 canid
Otarocyon macdonaldi Wang et al. 1999 bone-crushing dog | |
Proterix minimus Korth 2009 hedgehog
Amphechinus sp. Aymard 1850 hedgehog | |
Centetodon wolffi Macdonald 1965 placental
Centetodon marginalis Cope 1873 placental | |
Oligoryctes tenutalonidus n. sp. Korth et al. 2022 placental SDSM 150890 (holotype), dentary with m1-m3
Oligoryctes cf. cameronensis Hough 1956 placental | |
Micropternodus borealis Matthew 1903 placental
Micropternodus cf. montrosensis Ostrander 1983 placental | |
Apternodus cf. major Asher et al. 2002 placental | |
Noritrimylus compressus Galbreath 1953 shrew
Domnina gradata Cope 1873 shrew | |
Oligoscalops galbreathi Reed 1956 placental
Proscalops sp. Matthew 1901 placental | |
Blacktops sp. Meehan and Martin 2010 eutherian
Leptictis dakotensis Leidy 1868 eutherian |