# Washakie Formation

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.

## 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, and the rodents Pareumys flynni, Pauromys turnbulli and Thisbemys intermedius by Korth in 2020.

### Mammals

| Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon | Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited. |
Taeniodonts :
| Genus | Species | Presence | Material | Notes | Images |
| Stylinodon | S. mirus | Lower part of the Adobe Town Member. | 6 specimens. | A stylinodontid taeniodont. | |
Ferae :
| Genus | Species | Presence | Material | Notes |
| Carnivoraformes gen. indet. | species A | Adobe Town Member. | Tooth fragments. | A carnivoraform. |
| Carnivoraformes gen. indet. | species B | Adobe Town Member. | Teeth. | A carnivoraform. |
| Harpalodon | H. sylvestris | Adobe Town Member. | | A carnivoraform. |
| Hyaenodontidae | Hyaenodontidae gen. indet. | | 2 partial teeth. | A hyaenodont. |
| Limnocyon | L. potens | Adobe Town Member. | Partial skeleton. | A hyaenodont. |
| Limnocyon | L. verus | Adobe Town Member. | | A hyaenodont. |
| Lycarion | L. medius | Adobe Town Member. | Cranium, dentary and right humerus. | A carnivoraform. |
| Machaeroidinae | Machaeroidinae gen. indet. | | Posterior fragment of a right molar. | An oxyaenid. |
| Neovulpavus | N. mccarrolli | Adobe Town Member. | | A carnivoraform. |
| Neovulpavus | N. washakius | Adobe Town Member. | | A carnivoraform. |
| Oodectes | O. proximus | Adobe Town Member. | Labial fragment of right molar. | A miacid. |
| Oodectes | O. pugnax | Adobe Town Member. | Partial left dentary. | A miacid. |
| Patriofelis | P. ferox | Adobe Town Member. | | An oxyaenid. |
| Sinopa | S. lania | Adobe Town Member. | | A hyaenodont. |
| Sinopa | S. major | Adobe Town Member. | | A hyaenodont. |
| Sinopa | S. cf. S. minor | Adobe Town Member. | "FMNH PM 56405, right m1 with broken paraconid". | A hyaenodont. |
| Sinopa | S. species A | Adobe Town Member. | Left maxillary fragment. | A hyaenodont. |
| Thinocyon | T. cf. T. medius | Adobe Town Member. | Teeth. | A hyaenodont. |
| Thinocyon | T. velox | Adobe Town Member. | | A hyaenodont. |
| Tritemnodon | T. sp. | | Dentary fragments, fragments of vertebra and ulna. | A hyaenodont. |
| Uintacyon | U. jugulans | Adobe Town Member. | Left dentary fragment and right molar. | A miacid. |
| Viverravus | V. gracilis | Adobe Town Member. | Dentaries and teeth. | A viverravid. |
| Viverravus | V. minutus | Adobe Town Member. | Right dentary fragment. | A viverravid. |
| Viverravus | V. sp. indet. | | Right dentary fragment. | A viverravid. |
Rodents :
| Genus | Species | Presence | Material | Notes |
| Mattimys | M. sp. | Lower Adobe Town Member. | "FMNH PM 56559, right dentary fragment with m1." | An ischyromyid. |
| Metaparamys | M. compressidens | Middle and upper Adobe Town Member. | Skull fragment and dentaries. | An ischyromyid. |
| Mysops | M. sp. | Adobe Town Member. | "FMNH PM 55377, right m1 or m2." | A cylindrodontid. |
| Pareumys | P. flynni | Lower, middle and upper Adobe Town Member. | Dentaries and teeth. | A cylindrodontid. |
| Pauromys | P. turnbulli | Middle Adobe Town Member. | Dentaries. | A sciuravid. |
| Perasciuravus | P. mcintoshi | Lower and possibly middle Adobe Town Member. | | A sciuravid. |
| Protoptychus | P. hatcheri | Middle Adobe Town Member. | | |
| Quadratomus | Q. grandis | Lower Adobe Town Member. | "FMNH PM 55166, left M1 or M2; FMNH PM 55348, associated right p4 and m1." | An ischyromyid. |
| Thisbemys | T. intermedius | | | An ischyromyid. |
| Thisbemys | T. cf. T. uintensis | | | An ischyromyid. |
| Tillomys | T. senex | Lower and middle Adobe Town Member. | Left dentary and teeth. | A sciuravid. |
| Uintaparamys | U. bridgerensis | Lower and middle Adobe Town Member. | Left and right dentaries. | An ischyromyid. |
Ungulates :
| Genus | Species | Presence | Material | Notes |
| Amynodon | A. advenus | Middle unit of the Adobe Town Member. | | An amynodontid. |
| Dilophodon | D. minusculus | Middle unit of the Adobe Town Member. | | A helaletid. |
| Dolichorhinus | D. sp. | Middle unit of the Adobe Town Member. | | A brontothere. |
| Eobasileus | E. cornutus | Adobe Town Member. | | A dinoceratan. |
| Eomoropus | E. amarorum | Middle unit of the Adobe Town Member. | | An eomoropid. |
| Epihippus | E. gracilis | Upper unit of the Adobe Town Member. | | An equid. |
| cf. Forstercooperia | cf. F. minuta | Middle unit of the Adobe Town Member. | | A paracerathere, now reassigned to the genus Pappaceras. |
| Harpagolestes | H. immanis | Adobe Town Member. | | A mesonychid. |
| Harpagolestes | H. sp. indet. | | Mandibular fragments. | A mesonychid. |
| Helaletes | H. nanus | Kinney Rim Member. | | A helaletid. |
| Heliosus | H. apophis | Lower Adobe Town Member. | Dentary and associated humerus. | A helohyid. |
| Hyrachyus | H. eximius | Kinney Rim Member and lower unit of the Adobe Town Member. | | A rhinoceratoid. |
| Hyrachyus | H. modestus | Kinney Rim Member and lower unit of the Adobe Town Member. | | A rhinoceratoid. |
| Isectolophus | I. latidens | Lower unit of the Adobe Town Member. | | An isectolophid. |
| Mesatirhinus | M. 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. |
| Metarhinus | M. sp. | Middle unit of the Adobe Town Member. | | A brontothere. |
| Orohippus | O. sp. | | | An equid. |
| Pappaceras | P. minuta | Middle unit of the Adobe Town Member. | | A paracerathere. |
| Simidectes | aff. S.? | | Left molar. | A mesonychian. |
| Synoplotherium | S. lanius | Adobe Town Member. | | A mesonychid. |
| Synoplotherium | S. sp. indet. | | | A mesonychid. |
| Telmatherium | T. sp. | Lower unit of the Adobe Town Member. | | A brontothere. |
| Triplopus | T. cubitalis | Middle unit of the Adobe Town Member. | | A hyracodontid. |
| Triplopus | T. implicatus | | | A hyracodontid. |
| Uintatherium | U. anceps | Adobe Town Member. | | A dinoceratan. |

### Reptiles

| Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon | Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited. |
Birds :
| Genus | Species | Presence | Material | Notes | Images |
| Bathornis | B. grallator | "Sand Wash Basin, Wyoming, locality 196". | Partial skeleton (CM 9377). | A bathornithid. | |
| Neocathartes | N. grallator | "Sand Wash Basin, Wyoming, locality 196". | | Considered a junior synonym of Bathornis grallator. | |
Testudines :
| Genus | Species | Presence | Material | Notes | Images |
| Anosteira | A. pulchra | Adobe Town Member (Sweetwater County, Wyoming). | FMNH PR966, a near-complete cranium. | A carettochelyid turtle. | |