Little Muddy Creek (Niobrara County) ( of the United States)

Where: Niobrara County, Wyoming (43.0° N, 104.5° W: paleocoordinates 43.9° N, 98.7° W)

• coordinate based on political unit

When: Arikareean (29.5 - 18.5 Ma)

Environment/lithology: terrestrial

Primary reference: X. Xu. 1996. Castoridae. In D. R. Prothero and R. J. Emry (eds.), The Terrestrial Eocene-Oligocene Transition in North America 412-432 [J. Alroy/J. Alroy/J. Marcot]more details

PaleoDB collection 17532: authorized by John Alroy, entered by John Alroy on 19.05.2000, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

• Xu 1996 implies that the lower/middle levels are significantly older than the upper level, but separating out the records is impossible given the available literature
Mammalia
 Carnivora - Canidae
Otarocyon cooki10 Macdonald 1963 bone-crushing dog
Archaeocyon leptodus10 Schlaikjer 1935 bone-crushing dog
Phlaocyon minor10 Matthew 1907 bone-crushing dog
Philotrox condoni9 Merriam 1906 canid
level not indicated
Enhydrocyon pahinsintewakpa9 Macdonald 1963 canid
Ectopocynus antiquus n. sp.9 Wang 1994 canid
middle brown sand
Ectopocynus intermedius n. sp.9 Wang 1994 canid
10 ft below white layer in "low" horizon
 Perissodactyla - Rhinocerotidae
Diceratherium annectens4 Marsh 1873 rhinoceros
"Middle Arikareean, Monroe Creek Formation, 3.5 miles west of Muddy Creek Bridge, Niobrara County, Wyoming"
Diceratherium armatum4 Marsh 1875 rhinoceros
 Artiodactyla - Merycoidodontidae
"Desmatochoerus (Paradesmatochoerus) grangeri n. sp." = Mesoreodon minor6, "Mesoreodon cheeki" = Mesoreodon minor5, "Desmatochoerus wyomingensis" = Mesoreodon minor2, "Pithecistes altageringensis n. sp." = Leptauchenia decora7, "Hadroleptauchenia densa" = Leptauchenia major7, Sespia nitida7, Pseudodesmatochoerus milleri6, Megoreodon grandis6, "Mesoreodon megalodon" = Desmatochoerus megalodon5, Desmatochoerus hatcheri6
"Desmatochoerus (Paradesmatochoerus) grangeri n. sp." = Mesoreodon minor6 Douglass 1903 oreodont
F:AM 33303
"Mesoreodon cheeki" = Mesoreodon minor5 Douglass 1903 oreodont
"Desmatochoerus wyomingensis" = Mesoreodon minor2 Douglass 1903 oreodont
"Pithecistes altageringensis n. sp." = Leptauchenia decora7 Leidy 1856 oreodont
also their "L. parasimus" from "upper Gering"
"Hadroleptauchenia densa" = Leptauchenia major7 Leidy 1856 oreodont
includes their "Pseudocyclopidius lullianus"; both from the "upper Gering"
Sespia nitida7 Leidy 1869 oreodont
Pseudodesmatochoerus milleri6 Schultz and Falkenbach 1954 oreodont
Gering Fm.
Megoreodon grandis6 Douglass 1907 oreodont
"Mesoreodon megalodon" = Desmatochoerus megalodon5 Peterson 1907 oreodont
Desmatochoerus hatcheri6 Douglass 1907 oreodont
F:AM 33305 holotype of "Desmatochoerus hatcheri geringensis"
 Artiodactyla - Camelidae
Pseudolabis dakotensis3 Matthew 1904 camel
"Little Muddy Creek area, Goshen Co."
Miotylopus gibbi3 Loomis 1911 camel
"Little Muddy Creek, Niobrara County"
Miotylopus leonardi3 Loomis 1911 camel
"Little Muddy Creek area, Niobrara County"
 Artiodactyla - Moschidae
"Parablastomeryx falkenbachi" = Pseudoblastomeryx advena1
"Parablastomeryx falkenbachi" = Pseudoblastomeryx advena1 Matthew 1907 musk deer
"Little Muddy Creek"
 Rodentia - Florentiamyidae
"Florentiamys kennethi" = Florentiamys tiptoni8 Macdonald 1970 rodent
Florentiamys kingi8 Wahlert 1983 rodent
Gering Fm.
Florentiamys kinseyi8 Wahlert 1983 rodent
Gering Fm.
 Rodentia - Castoridae
Capacikala parvus n. sp. Xu 1996 beaver
"High level of middle brown sand, Little Muddy Creek" (i.e., upper level)
Capacikala gradatus Cope 1878 beaver
"Lower and middle Little Muddy Creek, Niobrara County"