PBDB Collection

Ridgeview (Oligocene of the United States)

Also known as UNSM Dw-121

Where: Dawes County, Nebraska (42.8° N, 103.0° W: paleocoordinates 43.7° N, 96.4° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Arikaree Group, Geringian (30.8 - 26.3 Ma)

• "Gering Fm." according to Swisher 1982, but "near the base of the Arikaree Group" (Bailey 1992) and "early early Arikareean" (= Geringian) (Bailey 2004)

• group of beds-level stratigraphic resolution

Environment/lithology: coarse channel fill; unlithified conglomerate

• "attributed to flashy, upper flow regime sheet flooding in a broad, low relief, principal paleochannel" (Bailey 2004)

• "1 m thick sequence of fluvial, plane-bedded sand and fine epiclastic gravel, deposited above a coarse intraclast conglomerate... plane-bedded fine gravel facies" (Bailey 2004)

Size class: mesofossils

Reposited in the UNSM

Collection methods: bulk, sieve,

• 1000+ identifiable specimens (Bailey 1992)

•rock censused includes processed "gravel concentrate" and not the original sediment (Bailey 2004)

Primary reference: B. E. Bailey. 1992. A new early Arikareean microfauna from northwestern Nebraska. Proceedings of the Nebraska Academy of Sciences 112:65 [J. Alroy/J. Alroy/M. Uhen]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 17709: authorized by John Alroy, entered by John Alroy on 26.03.1995, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

• "amphibians, reptiles, birds" and "fish" are present but not named (Bailey (2004)

Show authors, comments, and common names

Mammalia
Lagomorpha - Leporidae	Megalagus sp.¹, Palaeolagus philoi¹, Palaeolagus hypsodus¹ Megalagus sp.¹ Walker 1931 rabbit Palaeolagus philoi¹ Dawson 1958 rabbit Palaeolagus hypsodus¹ Schlaikjer 1935 rabbit
Rodentia - Cricetidae	Leidymys blacki¹, Geringia mcgregori¹ Leidymys blacki¹ Macdonald 1963 mouse Geringia mcgregori¹ Macdonald 1970 mouse
Rodentia - Allomyidae	cf. Allomys sp.¹, Downsimus chadwicki¹ cf. Allomys sp.¹ Marsh 1877 rodent Downsimus chadwicki¹ Macdonald 1970 rodent
Rodentia - Sciuridae	? Petauristodon sp.¹, Miospermophilus sp.¹, Protospermophilus sp.¹, Nototamias sp.¹ ? Petauristodon sp.¹ Engesser 1979 squirrel Miospermophilus sp.¹ Black 1963 squirrel n. sp. Protospermophilus sp.¹ Gazin 1930 squirrel Nototamias sp.¹ Pratt and Morgan 1989 squirrel n. sp.
Rodentia - Aplodontidae	cf. Prosciurus sp.¹, Meniscomys sp.¹, Campestrallomys dawsonae¹ cf. Prosciurus sp.¹ Matthew 1903 mountain beaver Meniscomys sp.¹ Cope 1878 mountain beaver Campestrallomys dawsonae¹ Macdonald 1963 mountain beaver
Rodentia - Eomyidae	Leptodontomys douglassi², Metadjidaumo cf. hendryi¹ Leptodontomys douglassi² Burke 1934 rodent Metadjidaumo cf. hendryi¹ Setoguchi 1978 rodent
Rodentia - Heliscomyidae	Heliscomys sp.³, Heliscomys macdonaldi n. sp.³, Tylionomys voorhiesi n. sp.³, "Heliscomys woodi" = Tylionomys woodi⁴ Heliscomys sp.³ Cope 1873 rodent UNSM 130501 - "UNSM 130501 cannot be referred to any of the other species of heliscomyid identified from the Ridgeview fauna based on the morphology of the lower premolar." Heliscomys macdonaldi n. sp.³ Korth and Branciforte 2007 rodent Tylionomys voorhiesi n. sp.³ Korth and Branciforte 2007 rodent "Heliscomys woodi" = Tylionomys woodi⁴ McGrew 1941 rodent
Rodentia - Geomyidae	Tenudomys ridgeviewensis n. sp.³, Tenudomys titanus³ Tenudomys ridgeviewensis n. sp.³ Korth and Branciforte 2007 pocket gopher Tenudomys titanus³ Martin 1974 pocket gopher
Rodentia - Heteromyidae	"Kirkomys schlaikjeri" = Proharrymys schlaikjeri¹, "Proheteromys fedti" = Proharrymys fedti¹, Proharrymys wahlerti n. sp.³ "Kirkomys schlaikjeri" = Proharrymys schlaikjeri¹ Black 1961 rodent "Proheteromys fedti" = Proharrymys fedti¹ Macdonald 1963 rodent Proharrymys wahlerti n. sp.³ Korth and Branciforte 2007 rodent
Rodentia - Castoridae	cf. Agnotocastor sp.¹ cf. Agnotocastor sp.¹ Stirton 1935 beaver
Rodentia - Florentiamyidae	Florentiamys tiptoni³, Sanctimus cf. stouti³, Sanctimus stuartae³ Florentiamys tiptoni³ Macdonald 1970 rodent Sanctimus cf. stouti³ Wahlert 1983 rodent UNSM 130243 Sanctimus stuartae³ Macdonald 1970 rodent
Placentalia -	Carnivora indet. Carnivora indet. Bowdich 1821 carnivoran
Theriamorpha - Erinaceidae	Ocajila makpiyahe¹ Ocajila makpiyahe¹ Macdonald 1963 hedgehog
Theriamorpha - Geolabididae	Centetodon cf. magnus¹ Centetodon cf. magnus¹ Clark 1936 placental
Theriamorpha - Proscalopidae	"Oligoscalops whitmanensis" = Oligoscalops galbreathi¹, Proscalops cf. miocaenus¹ "Oligoscalops whitmanensis" = Oligoscalops galbreathi¹ Reed 1956 placental Proscalops cf. miocaenus¹ Matthew 1901 placental
Theriamorpha - Talpidae	Scalopoides sp.⁴ Scalopoides sp.⁴ Wilson 1960 mole
Theriamorpha - Soricidae	Limnoecinae indet.¹, Domnina sp.¹ Limnoecinae indet.¹ Repenning 1967 shrew n. gen. et sp. Domnina sp.¹ Cope 1873 shrew
Macroscelidea - Amphilemuridae	Ankylodon annectens¹ Ankylodon annectens¹ Patterson and McGrew 1937 elephant shrew
Chiroptera - Vespertilionidae	Oligomyotis sp.¹, "Myotis" sp.¹ Oligomyotis sp.¹ Galbreath 1962 vesper bat a bat; ? Oligomyotis or ? Myotis sp. "Myotis" sp.¹ Kaup 1829 vesper bat
Theriamorpha - Herpetotheriidae	Herpetotherium cf. fugax¹ Herpetotherium cf. fugax¹ Cope 1873 marsupial
Theriamorpha - Peradectidae	Nanodelphys sp.¹ Nanodelphys sp.¹ McGrew 1937 marsupial n. sp.

¹Bailey 2004; ²Korth and Bailey 1992; ³Korth and Branciforte 2007; ⁴Tedford et al. 1996