The Washakie Formation is a geologic formation in northern Colorado and southern Wyoming. It preserves many mammal, bird, reptile and other fossils dating back to the Lutetian stage of the Eocene within the Paleogene period. The sediments fall in the Bridgerian and Uintan stages of the NALMA classification.Washakie Formation at Fossilworks.org

Fossil content The Washakie Formation has provided many fossil mammals, turtles and other reptiles, birds and other fossils.

The artiodactyl Heliosus apophis was described from the formation by Burger and Jolley,Burger & Jolley, 2020, p.178 and the rodents Pareumys flynni, Pauromys turnbulli and Thisbemys intermedius by Korth in 2020.

Mammals

Taeniodonts Genus Species Presence Material Notes Images StylinodonS. mirus Lower part of the Adobe Town Member.6 specimens. A stylinodontid taeniodont.

Ferae Genus Species Presence Material Notes ImagesCarnivoraformes gen. indet. species AAdobe Town Member.Tooth fragments.A carnivoraform.species BAdobe Town Member.Teeth.A carnivoraform.HarpalodonH. sylvestrisAdobe Town Member.A carnivoraform.HyaenodontidaeHyaenodontidae gen. indet.2 partial teeth.A hyaenodont.LimnocyonL. potensAdobe Town Member.Partial skeleton.A hyaenodont.L. verusAdobe Town Member.A hyaenodont.LycarionL. mediusAdobe Town Member.Cranium, dentary and right humerus.A carnivoraform.MachaeroidinaeMachaeroidinae gen. indet.Posterior fragment of a right molar.An oxyaenid.NeovulpavusN. mccarrolliAdobe Town Member.A carnivoraform.N. washakiusAdobe Town Member.A carnivoraform.OodectesO. proximusAdobe Town Member.Labial fragment of right molar.A miacid.O. pugnaxAdobe Town Member.Partial left dentary.A miacid. PatriofelisP. ferox Adobe Town Member. An oxyaenid.SinopaS. laniaAdobe Town Member.A hyaenodont.S. majorAdobe Town Member.A hyaenodont.S. cf. S. minorAdobe Town Member."FMNH PM 56405, right m1 with broken paraconid".A hyaenodont.S. species AAdobe Town Member.Left maxillary fragment.A hyaenodont.ThinocyonT. cf. T. mediusAdobe Town Member.Teeth.A hyaenodont.T. veloxAdobe Town Member.A hyaenodont.TritemnodonT. sp.Dentary fragments, fragments of vertebra and ulna.A hyaenodont.UintacyonU. jugulansAdobe Town Member.Left dentary fragment and right molar.A miacid.ViverravusV. gracilisAdobe Town Member.Dentaries and teeth.A viverravid.V. minutusAdobe Town Member.Right dentary fragment.A viverravid.V. sp. indet.Right dentary fragment.A viverravid.

Rodents Genus Species Presence Material Notes ImagesMattimysM. sp.Lower Adobe Town Member."FMNH PM 56559, right dentary fragment with m1."An ischyromyid. MetaparamysM. compressidens Middle and upper Adobe Town Member.Skull fragment and dentaries. An ischyromyid.MysopsM. sp.Adobe Town Member."FMNH PM 55377, right m1 or m2."A cylindrodontid.PareumysP. flynniLower, middle and upper Adobe Town Member.Dentaries and teeth.A cylindrodontid.PauromysP. turnbulliMiddle Adobe Town Member.Dentaries.A sciuravid.PerasciuravusP. mcintoshiLower and possibly middle Adobe Town Member.A sciuravid.ProtoptychusP. hatcheriMiddle Adobe Town Member.QuadratomusQ. grandisLower Adobe Town Member."FMNH PM 55166, left M1 or M2; FMNH PM 55348, associated right p4 and m1."An ischyromyid.ThisbemysT. intermediusAn ischyromyid.T. cf. T. uintensisAn ischyromyid.TillomysT. senexLower and middle Adobe Town Member.Left dentary and teeth.A sciuravid.UintaparamysU. bridgerensisLower and middle Adobe Town Member.Left and right dentaries.An ischyromyid.

Ungulates Genus Species Presence Material Notes ImagesAmynodonA. advenusMiddle unit of the Adobe Town Member.An amynodontid.DilophodonD. minusculusMiddle unit of the Adobe Town Member.A helaletid.DolichorhinusD. sp.Middle unit of the Adobe Town Member.A brontothere.EobasileusE. cornutusAdobe Town Member.A dinoceratan.EomoropusE. amarorumMiddle unit of the Adobe Town Member.An eomoropid.EpihippusE. gracilisUpper unit of the Adobe Town Member.An equid.cf. Forstercooperiacf. F. minutaMiddle unit of the Adobe Town Member.A paracerathere, now reassigned to the genus Pappaceras.HarpagolestesH. immanisAdobe Town Member.A mesonychid.H. sp. indet.Mandibular fragments.A mesonychid.HelaletesH. nanusKinney Rim Member.A helaletid.HeliosusH. apophisLower Adobe Town Member.Dentary and associated humerus.A helohyid.HyrachyusH. eximiusKinney Rim Member and lower unit of the Adobe Town Member.A rhinoceratoid.H. modestusKinney Rim Member and lower unit of the Adobe Town Member.A rhinoceratoid.IsectolophusI. latidensLower unit of the Adobe Town Member.An isectolophid.MesatirhinusM. sp.Kinney Rim Member and lower unit of the Adobe Town Member.Over 20 partial skeletons.A brontothere.Mesonychia?Mesonychia? gen. indet.Teeth.A mesonychian.MetarhinusM. sp.Middle unit of the Adobe Town Member.A brontothere.OrohippusO. sp.An equid.PappacerasP. minutaMiddle unit of the Adobe Town Member.A paracerathere.Simidectesaff. S.?Left molar.A mesonychian.SynoplotheriumS. laniusAdobe Town Member.A mesonychid.S. sp. indet.A mesonychid.TelmatheriumT. sp.Lower unit of the Adobe Town Member.A brontothere.TriplopusT. cubitalisMiddle unit of the Adobe Town Member.A hyracodontid.T. implicatusA hyracodontid. UintatheriumU. anceps Adobe Town Member. A dinoceratan.

Reptiles

Birds Genus Species Presence Material Notes ImagesBathornisB. grallator"Sand Wash Basin, Wyoming, locality 196".Partial skeleton (CM 9377).A bathornithid.NeocathartesN. grallator"Sand Wash Basin, Wyoming, locality 196".Considered a junior synonym of Bathornis grallator.

Testudines Genus Species Presence Material Notes Images AnosteiraA. pulchra Adobe Town Member (Sweetwater County, Wyoming).FMNH PR966, a near-complete cranium. A carettochelyid turtle.

See also List of fossiliferous stratigraphic units in Wyoming Paleontology in Wyoming Bridger Formation Green River Formation Uinta Formation Wasatch Formation

References

Bibliography

Further reading

W. G. Joyce, V. S. Volpato, and Y. Rollot. 2018. The skull of the carettochelyid turtle Anosteira pulchra from the Eocene (Uintan) of Wyoming and the carotid canal system of carettochelyid turtles. Fossil Record 21:301-310 N. Vitek. 2011. Insights into the Taxonomy and Systematics of North American Eocene Soft-Shelled Turtles from a Well-Preserved Specimen. Bulletin of the Peabody Museum of Natural History 52(2):189-208 S. M. McCarroll, J. J. Flynn, and W. D. Turnbull. 1996. Biostratigraphy and magnetostratigraphy of the Bridgerian-Uintan Washakie Formation, Washakie Basin, Wyoming. In D. R. Prothero and R. J. Emry (eds.), The Terrestrial Eocene-Oligocene Transition in North America 25-39 R. K. Stucky, D. R. Prothero, W. G. Lohr and J. R. Snyder. 1996. Magnetic stratigraphy, sedimentology, and mammalian faunas of the early Uintan Washakie Formation, Sand Wash Basin, northwestern Colorado. In D. R. Prothero and R. J. Emry (eds.), The Terrestrial Eocene-Oligocene Transition in North America 40-51 S. M. McCarroll, J. J. Flynn, and W. D. Turnbull. 1996. The Mammalian Faunas of the Washakie Formation, Eocene Age, of Southern Wyoming. Part III. The Perissodactyls. Fieldiana, Geology 33:1-38 A. Wetmore. 1944. A new terrestrial vulture from the Upper Eocene deposits of Wyoming. Annals of Carnegie Museum 30:57-69 R. Zangerl. 1944. Brachyuranochampsa eversolei, gen. et sp. nov., a new crocodilian from the Washakie beds of Wyoming. Annals of Carnegie Museum 30:77-84 O. P. Hay. 1908. The fossil turtles of North America. Carnegie Institution of Washington Publication 75:1-568