Runningwater Formation

The Runningwater Formation is a geologic formation in Nebraska. It preserves fossils dating back to the Hemingfordian of the Early Miocene of the Neogene period. The sandstones and conglomerates of the formation were deposited in a fluvial environment. The formation has provided many fossil mammals.

Runningwater Formation
Stratigraphic range: Early Miocene (Hemingfordian) ~20.6–16.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Formation
Lithology
Primary	Sandstone
Other	Conglomerate
Location
Coordinates	42.4°N 103.0°W / 42.4; -103.0
Approximate paleocoordinates	43.1°N 99.1°W / 43.1; -99.1
Region	Nebraska
Country	United States
Runningwater Formation (the United States) Show map of the United States Runningwater Formation (Nebraska) Show map of Nebraska

Fossil content

Among the following fossils have been found in the formation:^[1]

Mammals

• Aletomeryx gracilis
• Arretotherium fricki
• Barbouromeryx trigonocorneus
• Cynarctoides acridens
• Cynelos stenos^[2]
• Diceratherium niobrarense
• Daphoenodon (Borocyon) robustum
• Desmocyon thomsoni
• Hypertragulus minor
• Menoceras barbouri
• Merychyus arenarum, M. elegans
• Metatomarctus canavus
• Osbornodon iamonensis
• Pseudoblastomeryx advena
• Anchitheriomys stouti
• Desmatippus tyleri
• Edaphocyon lautus
• Amphicyon galushai
• Craterogale cf. simus
• Leptarctus cf. ancipidens
• Leptocyon vulpinus
• Tephrocyon scitulus
• Merycochoerus proprius

Reptiles

• Macrochelys schmidti
• Rhineura marslandensis
• Sceloporus sp.

See also

• List of fossiliferous stratigraphic units in Nebraska
• Paleontology in Nebraska