The Ash Hollow Formation of the Ogallala Group is a geological formation found in Nebraska and South Dakota. It preserves fossils dating back to the Neogene period. It was named after Ash Hollow, Nebraska and can be seen in Ash Hollow State Historical Park. Ashfall Fossil Beds State Historical Park is within this formation.
Fossil content
Mammals Bats Bats reported from the Ash Hollow Formation Genus Species Location Stratigraphic positionMaterial Notes Images LasiurusL. sp. indet. Pratt Slide, Brown County, Nebraska.Merritt Dam Member.Distal portion of a left humerus (UNSM 100140). A hairy-tailed bat. MyotisM. sp. indet.Ashfall Fossil Beds.Cap Rock Member.A right dentary (UNSM 27898).A mouse-eared bat.
Carnivorans Carnivorans reported from the Ash Hollow Formation Genus Species Location Stratigraphic positionMaterial Notes ImagesAelurodonA. taxoidesBrown, Cherry, Keyapaha, Knox, Sheridan, Hitchcock & Banner counties, Nebraska.Cap Rock & Merritt Dam Members.Abundant remains.A borophagine dog.BarbourofelisB. frickiChannel deposits resting on upper part of the formation.A barbourofelid.B. morrisiCherry County, Nebraska.Channel deposit resting unconformably on the Cap Rock Member.Skull (F:AM 79999) and right ramus (F:AM 80000).A barbourofelid.?B. whitfordiBrown County, Nebraska.Lower part of the formation.Right ramus (UNSM 25546).A barbourofelid.CarpocyonC. robustusBrown & Cherry counties, Nebraska.Merritt Dam Member.Skull elements.A borophagine dog.EpicyonE. haydeniBrown, Cherry, Keith and Sheridan counties, Nebraska.Merritt Dam Member.Multiple specimens.A borophagine dog.E. saevusBrown, Cherry, Antelope & Keith counties, Nebraska.Cap Rock & Merritt Dam members.Multiple specimens.A borophagine dog.Eucyon?E.? skinneriHans Johnson Quarry, Cherry County, Nebraska.Merritt Dam Member.Partial mandible (F:AM 25143).A canine dog.IschyrocyonI. gidleyiCherry & Keyapaha counties, Nebraska; Todd, Bennett & Mellette counties, South Dakota.Cap Rock Member.A bear-dog.LeptarctusL. wortmaniNebraska & South Dakota.Many undescribed specimens.A mustelid.LeptocyonL. matthewiCherry, Brown & Antelope counties, Nebraska.Merritt Dam & Cap Rock members.Skull and limb elements.A canine dog. MetalopexM. merriami Frontier County, Nebraska.Premaxilla, maxilla and ramus fragments. A fox. ParatomarctusP. euthosBrown & Cherry counties, Nebraska, & Todd County, South Dakota.Cap Rock & Merritt Dam members.Numerous specimens.A borophagine dog.PseudocyonP. sp.Brown & Cherry counties, Nebraska.Cap Rock & Merritt Dam members.A bear-dog.VulpesV. stenognathusFrontier County, Nebraska.Left molar (UNSM 26136).A fox.
Eulipotyphlans Eulipotyphlans reported from the Ash Hollow Formation Genus Species Location Stratigraphic positionMaterial Notes ImagesAchlyoscapterA. sp.Lemoyne Quarry, Keith County, Nebraska.A right ramal fragment (UW 6670).A talpine mole.AlluvisorexA. sp., cf. A. arcadentesLemoyne Quarry, Keith County, Nebraska.UW 6734, 6735 & 7722; UNSM 27515.A shrew.AnouroneomysA. magnusLemoyne Quarry, Keith County, Nebraska.A shrew.LemoyneaL. biradicularisLemoyne Quarry, Keith County, Nebraska.A desmanine mole.Limnoecuscf. L. sp.Lemoyne Quarry, Keith County, Nebraska.UW 6708 & 6739.A medium-sized shrew.SorexS. edwardsiLemoyne Quarry, Keith County, Nebraska. A medium-sized shrew.S. yatkolaiLemoyne Quarry, Keith County, Nebraska.UW 6731 (fragment of left ramus), 6732 & 6733.A diminuitive shrew.S. sp.Lemoyne Quarry, Keith County, Nebraska.UW 6736, 6737 & 6738.Probably a new species of shrew, larger than S. edwardsi.TalpinaeUndetermined genus & species 1Lemoyne Quarry, Keith County, Nebraska.2 teeth (UW 6671 & 10527).A mole.Undetermined genus & species 2Lemoyne Quarry, Keith County, Nebraska.Teeth (UW 10521, 10522, 10523, 10524, 10525 & 10526).A mole.Undetermined genus & species 3Lemoyne Quarry, Keith County, Nebraska.An isolated right molar (UW 6675).A mole.
Lagomorphs Lagomorphs reported from the Ash Hollow Formation Genus Species Location Stratigraphic positionMaterial Notes ImagesAlilepusA. sp.Pratt Quarry, Brown County, Nebraska.Merritt Dam Member.Mandible and teeth.A leporid. HesperolagomysH. sp., cf. H. galbreathiPratt Quarry, Brown County, Nebraska.Merritt Dam Member.A premolar (UNSM 101709). A pika.HypolagusH. cf. H. vetusPratt Quarry, Brown County, Nebraska.Merritt Dam Member.A right premolar (UNSM 101749).A leporid.PronotolagusP. whiteiPratt Quarry, Brown County, Nebraska.Merritt Dam Member.An isolated premolar (UNSM 101675).A leporid.RussellagusR. sp.Pratt Quarry, Brown County, Nebraska.Merritt Dam Member.Lower molariform teeth.A pika.
Rodents Rodents reported from the Ash Hollow Formation Genus Species Location Stratigraphic positionMaterial Notes ImagesAmmospermophilusA. junturensisPratt Quarry, Brown County, Nebraska.Merritt Dam Member.Mandible and teeth.An antelope squirrel.AntecalomysA. phthanusPratt Quarry, Brown County, Nebraska.Merritt Dam Member.Teeth and mandibles.A sigmodontine, and the most common fossil cricetid from Pratt Quarry.CeratogaulusC. anecdotusBrown County, Nebraska.Merritt Dam & Cap Rock members.Skulls, teeth and some postcranial remains.A mylagaulid.CopemysC. mariaePratt Quarry, Brown County, Nebraska.Merritt Dam Member.Mandibles.A cricetid.C. pisinnusPratt Quarry, Brown County, Nebraska.Merritt Dam Member.Mandibles and a maxilla.A cricetid.C. sp.Pratt Quarry, Brown County, Nebraska.Merritt Dam Member.An isolated right molar (UNSM 101560).A cricetid.CupidinimusC. prattensisPratt Quarry, Brown County, Nebraska.Merritt Dam Member.A right mandible (UNSM 101501).A dipodomyine.DipoidesD. tanneriPratt Quarry, Brown County, Nebraska.Merritt Dam Member.A little worn premolar (UNSM 101612).A castorid.EucastorE. planusPratt Quarry, Brown County, Nebraska.Merritt Dam Member.Teeth and a partial mandible.Reassigned to Nothodipoides.HystricopsH. venustusPratt Quarry, Brown County, Nebraska.Merritt Dam Member.Teeth.A castorid.LignimusL. sp.Pratt Quarry, Brown County, Nebraska.Merritt Dam Member.Teeth and mandible.A possible harrymyine.MegasminthusM. sp. indeterminatePratt Quarry, Brown County, Nebraska.Merritt Dam Member.Maxillae.A jumping mouse.MioheteromysM. sp., cf. M. agrariusPratt Quarry, Brown County, Nebraska.Merritt Dam Member.An isolated premolar (UNSM 101750) and a partial mandible with lower incisor (UNSM 101573).A heteromyid. MylagaulusM. monodon Pratt Quarry, Brown County, Nebraska.Merritt Dam Member.Teeth, mandible and limb elements. A mylagaulid.NothodipoidesN. planusBrown County, Nebraska & Todd County, South Dakota.Merritt Dam Member.Teeth, partial mandible & partial skull.A castorid.PerognathusP. sp.Antelope County, Nebraska.Fragmentary remains within burrows.A pocket-mouse.?Petauristodon?P. sp.Pratt Quarry, Brown County, Nebraska.Merritt Dam Member.A molar (UNSM 101659).A petauristine, may represent a new species.PhelosaccomysP. hibbardiPratt Quarry, Brown County, Nebraska.Merritt Dam Member.Teeth.A possible geomyid.ProdipoidesP. dividerusNebraska.Merritt Dam Member.A castorid.ProtospermophilusP. sp., cf. P. quatalensisPratt Quarry, Brown County, Nebraska.Merritt Dam Member.An isolated molar (UNSM 101765).A ground squirrel.Pseudotheridomyscf. P. sp.Pratt Quarry, Brown County, Nebraska.Merritt Dam Member.A right mandible with teeth (UNSM 101748).An eomyid.PterogaulusP. barbarellaeNebraska.Merritt Dam Member.A mylagaulid.cf. Sciurioncf. S. sp.Pratt Quarry, Brown County, Nebraska.Merritt Dam Member.An isolated left molar (UNSM 101769).A flying squirrel.SpermophilusS. (Otospermophilus) sp.Pratt Quarry, Brown County, Nebraska.Merritt Dam Member.Teeth and jaws.A ground squirrel.TregomysT. shotwelliPratt Quarry, Brown County, Nebraska.Merritt Dam Member.An isolated right molar (UNSM 101534).A cricetid.
Ungulates Ungulates reported from the Ash Hollow Formation Genus Species Location Stratigraphic positionMaterial Notes ImagesAepycamelusA.spNebraska.Cap Rock Member.A Camelid.CalippusC. cerasinusCherry County, Nebraska.Merritt Dam Member.Multiple specimens.An equid.C. placidusMinnechaduza Fauna, northern Nebraska.Cap Rock & lower Merritt Dam members.An equid.CormohipparionC. frickiHollow Horn Bear Quarry, Todd County, South Dakota.Skull elements.An equid.C. matthewiCherry County, Nebraska.Merritt Dam Member.Multiple specimens.An equid.C. occidentaleCherry County, Nebraska.Merritt Dam Member.Numerous specimens.An equid.MacrogenisM. crassigenisAbove Burge Quarry, Brown County, Nebraska.Merritt Dam Member.Partial skull (F:AM AINS 467-333-1).A peccary.MckennahyusM. parisidutraiCherry County, Nebraska.Merritt Dam Member.Skull remains.A peccary.ProantilocapraP. platycorneaNebraska.Cap Rock Member.An antilocaprid.PseudhipparionP. gratumCherry County, Nebraska.Cap Rock & lower Merritt Dam members.An equid.P. skinneriBrown & Cherry counties, Nebraska.Merritt Dam Member.Skull elements & teeth.An equid also known from Florida.PseudocerasP. potteriNebraska.Merritt Dam Member.Junior synonym of P. skinneri.P. skinneriNebraska.Merritt Dam Member.Multiple specimens.A gelocid.P. wilsoniNebraska.Merritt Dam Member.Junior synonym of P. skinneri.SkinnerhyusS. shermerorumCherry County, Nebraska.Merritt Dam Member.Skull remains.A peccary.TapirusT. johnsoniBrown (Pratt Slide), Cherry, Sheridan & Garden counties, Nebraska.Merritt Dam Member.Jaw elements.A tapir.TeleocerasT. majorAshfall Fossil Beds, Nebraska.Over 100 specimens. A rhinoceros.UstatochoerusU. majorCherry County, Nebraska.Upper part of the formation.Numerous specimens.A merycoidodontid.U. profectusCap Rock Member.Numerous specimens.A merycoidodontid.U. skinneriCherry & Brown counties, Nebraska; Tripp County, South Dakota.Multiple specimens.A merycoidodontid.
Proboscideans Proboscideans reported from the Valentine FormationGenusSpeciesLocationStratigraphic positionMaterialNotesImagesAmebelodonA. frickiFrontier & Garden counties, Nebraska.A gomphothere.EubelodonE. morrilli Cap rockA gomphothere.SerbelodonS. barbourensisCherry & Morrill counties, Nebraska.Merrit DamA gomphothere.
Reptiles Birds Birds reported from the Ash Hollow Formation Genus Species Location Stratigraphic positionMaterial Notes ImagesAnasA. greeniBennett County, South Dakota.Distal half of a right humerus.A teal duck originally reported as Nettion greeni.AnchigypsA. voorhiesiNear the town of Orchard, Antelope County, Nebraska.Cap Rock Member.Partial skeleton (UNSM 62877).An accipitrid resembling an Old World vulture.ApatosagittariusA. terrenusNebraska."A nearly complete tarsometatarsus with phalanges in place".An accipitrid convergent with the secretarybird. CenturiavisC. lioae Nebraska.Merritt Dam Member.An exquisitely preserved partial skeleton. A phasianid.NettionN. greeniBennett County, South Dakota.Distal half of a right humerus.Lumped into the genus Anas.
Crocodilians Crocodilians reported from the Ash Hollow Formation Genus Species Location Stratigraphic positionMaterial Notes ImagesAlligatorA. mefferdiCherry County, Nebraska.Upper portion of the formation.A well-preserved skull and jaws, with some postcranial bones.An alligator. Crocodilia Antelope County, Nebraska.Caprock Member.2 teeth & a dermal plate.
Squamates