Uintatherium is an extinct genus of herbivorous dinoceratan mammal that lived during the Eocene epoch. Two species are currently recognized: U. anceps from the United States during the Early to Middle Eocene and U. insperatus of Middle to Late Eocene China.
Miacis is an extinct genus of placental mammals from clade Carnivoraformes, that lived in North America from the early to middle Eocene.
Oxyaena is an extinct genus of placental mammals from extinct subfamily Oxyaeninae within extinct family Oxyaenidae, that lived in Europe, Asia and North America during the early Eocene.
Cimolestes is a genus of early eutherians with a full complement of teeth adapted for eating insects and other small animals. Paleontologists have disagreed on its relationship to other mammals, in part because quite different animals were assigned to the genus, making Cimolestes a grade taxon of animals with similar features rather than a genus of closely related ones. Fossils have been found in North America, South America, Europe and Africa. Cimolestes first appeared during the Late Cretaceous of North America. According to some paleontologists, Cimolestes died out at the start of the Paleocene, while others report the genus from the early Eocene.
Machaeroides ("dagger-like") is an extinct genus of sabre-toothed predatory placental mammals from extinct subfamily Machaeroidinae within extinct family Oxyaenidae, that lived in North America (Wyoming) from the early to middle Eocene.
Priscacara, is a genus of extinct temperate bass described from Early to Middle Eocene fossils. It is characterized by a sunfish-like body and its stout dorsal and anal spines. The genus is best known from the Green River Formation of Wyoming, Utah and Colorado. Mass deaths of Priscacara suggest it formed schools.
Procaimanoidea is an extinct genus of alligatorid from the Eocene of North America. It was named posthumously in 1946 by Charles W. Gilmore; the type species is P. utahensis, from the Uintan of Utah. It is based on USNM 15996, a nearly complete skull and partial left hind leg. A second species, P. kayi, was named in 1941 by C.C. Mook as a species of Hassiacosuchus, for remains from the Bridgerian of Wyoming. It was reassigned to Procaimanoidea in 1967 by Wassersug and Hecht.
Didymictis is an extinct genus of placental mammals from extinct subfamily Didymictinae within extinct family Viverravidae, that lived in North America and Europe from the late Paleocene to middle Eocene.
Tritemnodon was an extinct genus of placental mammals from extinct order Hyaenodonta, that lived in North America during the early Eocene. Fossils of Tritemnodon agilis have been found in Utah and Wyoming. It was the size of a wolf.
Tillodontia is an extinct suborder of eutherian mammals known from the Early Paleocene to Late Eocene of China, the Late Paleocene to Middle Eocene of North America where they display their maximum species diversity, the Middle Eocene of Pakistan, and the Early Eocene of Europe. Leaving no descendants, they are most closely related to the pantodonts, another extinct group. The tillodonts were medium- to large-sized animals that probably fed on roots and tubers in temperate to subtropical habitats.
Allognathosuchus is an extinct genus of alligatorine crocodylian with a complicated taxonomic history. It was named in 1921.
Brachyhyops is an extinct genus of entelodont artiodactyl mammal that lived during the Eocene Epoch of western North America and southeastern Asia. The first fossil remains of Brachyhyops are recorded from the late Eocene deposits of Beaver Divide in central Wyoming and discovered by paleontology crews from the Carnegie Museum of Natural History during the early 20th century. The type species, Brachyhyops wyomingensis, is based on a single skull and was named by E.H. Colbert in 1937, but was not officially described until 1938. During the latter half of the 20th century, additional specimens from North America have been recorded from Saskatchewan and as far south as Texas, indicating that Brachyhyops had a broad distribution and was well-dispersed throughout western North America.
Sinopa is an extinct genus of placental mammals from extinct family Sinopidae within extinct order Hyaenodonta, that lived in North America and Asia from the early to middle Eocene.
The Wasatch Formation (Tw) is an extensive highly fossiliferous geologic formation stretching across several basins in Idaho, Montana, Wyoming, Utah and western Colorado. It preserves fossils dating back to the Early Eocene period. The formation defines the Wasatchian or Lostcabinian, a period of time used within the NALMA classification, but the formation ranges in age from the Clarkforkian to Bridgerian.
Suzanniwana is an extinct genus of iguanian lizards that lived in western North America during the earliest Eocene, approximately 56 million years ago. Two species are known from the Bighorn Basin of Wyoming: the type species S. patriciana named in 2009, and the species S. revenanta named in 2013. Suzanniwana lived during the Paleocene–Eocene Thermal Maximum, a brief period of global warming that resulted in warmer and drier conditions in the Bighorn Basin. It likely stemmed from a lineage that had migrated into the basin from regions farther to the south, following a latitudinal band of constant climatic conditions that moved northward as the planet warmed. Suzanniwana shares many skeletal features with modern casquehead lizards of the family Corytophanidae and may be a stem-corytophanid. It also closely resembles Geiseltaliellus, an iguanian from the middle Eocene Messel pit in Germany.
Aleiodes gaga is a species of parasitoid wasp belonging to the family Braconidae. It was first described by Donald Quicke and Buntika Butcher in 2012 after a single individual was discovered in the Chae Son National Park in Thailand. The species is named after Lady Gaga. This species is one of 179 species identified by the first "turbo-taxonomic" search of DNA barcoding of cytochrome oxidase I (COI).
Homacodontidae is an extinct family of basal artiodactyl mammals from the early Eocene to late Oligocene of North America, Europe, and Asia.
Wyonycteris is a genus of small mammals that existed in the late Paleocene and early Eocene epochs. The type species is Wyonycteris chalix, which lived in Wyoming during the Clarkforkian North American Land Mammal Age of the Paleocene and was originally proposed to be an early form of insectivorous bat. Later re-examination of the material has put this alliance in doubt, and the genus has instead been proposed as belonging to the subfamily Placentidentinae, within the family Nyctitheriidae. Similar fossil material of the same time period found in Europe was later discovered and described as new species, Wyonycteris richardi.
Kaikaia is a genus of treehopper endemic to Nicaragua, containing the single species Kaikaia gaga. It was described in 2020 by Brendan Morris, a Ph.D. student at the University of Illinois at Urbana-Champaign. It entered the news when it was revealed that the insect was named after Lady Gaga.
Azygonyx was a small tillodont mammal, likely the size of a cat to raccoon, that lived in North America during the Paleocene and Eocene in the early part of the Cenozoic Era. The only fossils that have been recovered are from the Willwood and Fort Union Formations in the Bighorn Basin of Wyoming, United States, and date to the Clarkforkian to Wasatchian, about 56 to 50 million years ago. Fifty-six collections that have been recovered thus far include the remains of Azygonyx. Azygonyx survived the Paleocene Eocene Thermal Maximum along with other mammals like Phenacodus and Ectocion, both of which were ground-dwelling mammals. Azygonyx probably was a generalist terrestrial mammal that may have roamed around the ground, but was also capable of climbing trees.
