Wasatchian

Barylambda (Greek: "heavy" (baros), "lambda" (lambda) in a reference to larger size than that of Pantolambda) is an extinct genus of pantodont mammal from the middle to late Paleocene, well known from several finds in the Wasatchian (NALMA classification) DeBeque Formation of Colorado and the Clarkforkian Wasatch Formation to Tiffanian Fort Union Formation in Wyoming. Three species of Barylambda are currently recognized. The creature likely lived a life similar to that of a modern tapir, browsing on foliage and soft vegetation. Barylambda seems to have been quite successful for an early pantod

Notharctus is a genus of adapiform primate that lived in North America and Europe during the early to middle Eocene. left|thumb|N. tenebrosus (left) compared to Plesiadapis|Plesiadapis cookei (right), a plesiadapiform. Both come from [[Eocene Wyoming, though the latter is slightly geologically older (Museum of Natural Sciences, Brussels).]] The body form of Notharctus is similar to that of modern rats. Its fingers were elongated for clamping onto branches, including the development of a thumb. Its spine is flexible and the animal was about in length, excluding the long tail.

Sifrhippus is an extinct genus of equid containing the species S. sandrae. Sifrhippus is the oldest known equid, living during the early Eocene. Its fossils were discovered in the Bighorn Basin of Wyoming.

Carpolestes (from Ancient Greek καρπός (karpós), meaning "fruit", and λῃστής (lēistḗs), meaning "robber", and thus, "fruit robber") is a genus of extinct primate-like mammals from the late Paleocene of North America. It first existed around 58 million years ago. The three species of Carpolestes appear to form a lineage, with the earliest occurring species, C. dubius, ancestral to the type species, C. nigridens, which, in turn, was ancestral to the most recently occurring species, C. simpsoni.

Diacodexis is an extinct genus of small herbivorous mammals belonging to the family Diacodexeidae that lived in North America and Europe from 55.4 mya to 46.2 mya, existing for approximately .

Gagadon ("Gaga tooth") is an extinct genus of even-toed ungulate that lived in the early Eocene of North America. The type and only known species, Gagadon minimonstrum, was described in 2014 based on lower teeth and jaw fragments found in the Wasatch Formation of Bitter Creek, Wyoming. The genus is named in honor of the singer Lady Gaga, while the species name minimonstrum ("mini monster") refers simultaneously to the small size and presence of unusual cusps on the teeth and to Gaga's name for her fans, the "little monsters".

Smilodectes is a genus of adapiform primate that lived in North America during the middle Eocene. It possesses a post-orbital bar and grasping thumbs and toes. Smilodectes has a small cranium size and the foramen magnum was located at the back of the skull, on the occipital bone.

Ignacius is a genus of extinct mammal from the early Cenozoic era. This genus is present in the fossil record from around 62-33 Ma (late Torrejonian-Chadronian North American Land Mammals Ages). The earliest known specimens of Ignacius come from the Torrejonian of the Fort Union Formation, Wyoming and the most recent known specimens from Ellesmere Island in northern Canada. Ignacius is one of ten genera within the family Paromomyidae, the longest living family of any plesiadapiforms, persisting for around 30 Ma during the Paleocene and Eocene epochs. The analyses of postcranial fossils by pale