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.
Fossil content
Among the following fossils have been found in the formation:;MammalsAletomeryx gracilisArretotherium frickiBarbouromeryx trigonocorneusCynarctoides acridensCynelos stenosDiceratherium niobrarenseDaphoenodon (Borocyon) robustumDesmocyon thomsoniHypertragulus minorMenoceras barbouriMerychyus arenarum, M. elegansMetatomarctus canavusOsbornodon iamonensisPseudoblastomeryx advenaAnchitheriomys stoutiDesmatippus tyleriEdaphocyon lautusAmphicyon galushaiCraterogale cf. simusLeptarctus cf. ancipidensLeptocyon vulpinusTephrocyon scitulusMerycochoerus proprius
;ReptilesMacrochelys schmidtiRhineura marslandensis
- ''Sceloporus sp.''