Roundhouse Rock Gap ( of the United States)

Also known as Mo-104, in part

Where: Morrill County, Nebraska (41.7° N, 103.1° W: paleocoordinates 42.6° N, 97.3° W)

• coordinate based on political unit

When: Brown Siltstone Member (Brule Formation), Arikareean (30.8 - 20.4 Ma)

• Unit A

Environment/lithology: terrestrial

Primary reference: C. C. Swisher. 1982. Stratigraphy and biostratigraphy of the eastern portion of the Wildcat Ridge, western Nebraska. 1-172 [J. Alroy/J. Alroy/J. Marcot]more details

PaleoDB collection 17602: authorized by John Alroy, entered by John Alroy on 18.02.1993, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

• a.k.a. Horn Member of Brule Formation
said to include both the E of and 1/4 mi NW of Roundhouse Rock localities by Schultz and Falkenbach 1968
Roundhouse Rock Ash dated at 28.59 +/- 0.32 Ma by Prothero and Swisher 1992; this is within Unit A based on Tedford et al. 1996
status unclear: Mesoreodon "cheeki" Schultz and Falkenbach 1949: Gering Fm. at "Round House Rock, Pumpkin Creek, Morrill County" "Mesoreodon" megalodon Schultz and Falkenbach 1949: Gering Fm. at "Round House Rock" "Desmatochoerus wyomingensis" Schultz and Falkenbach 1954: "Roundhouse Rock"
Mesoreodon does not range above Gering B, which is not exposed at Roundhouse Rock
Mammalia
 Artiodactyla - Camelidae
Miotylopus gibbi1 Loomis 1911 camel
 Artiodactyla - Merycoidodontidae
"Desmatochoerus (Paradesmatochoerus) wyomingensis" = Mesoreodon minor2, Sespia nitida3, Leptauchenia major3
"Desmatochoerus (Paradesmatochoerus) wyomingensis" = Mesoreodon minor2 Douglass 1903 oreodont
Mo-107 and -108
Sespia nitida3 Leidy 1869 oreodont
Leptauchenia major3 Leidy 1856 oreodont
 Carnivora - Palaeogalidae
Palaeogale dorothiae Macdonald 1963 carnivoran
 Carnivora - Canidae
Archaeocyon leptodus4 Schlaikjer 1935 bone-crushing dog
"15 ft above marl, upper part" of member