Chattian genus extinctions

Eusmilus ('true sabre') is a prehistoric genus of nimravid that lived in Europe and North America during the Late Eocene to Early Oligocene epochs (34.7–29.5 mya).

Anthracotherium (from Ancient Greek ἄνθραξ (ánthrax), meaning "coal", and θηρίον (theríon), meaning "beast") is an extinct genus of anthracotheriid artiodactyls characterized by having 44 teeth, with five semi-crescentic cusps on the crowns of the upper molars. The genus ranged from the middle Eocene period until the early Miocene, having a distribution throughout Eurasia probably even reaching South East Asia (Kalimantan and West Timor). Material subjectively assigned to Anthracotherium from Pakistan suggests the last species died out soon after the start of the Miocene.

Nimravus is an extinct genus of "false" saber-toothed cat that lived in North America and Eurasia during the Eocene and Oligocene epochs 35.3—27.1 mya, existing for approximately . Not closely related to true saber-toothed cats, they evolved a similar form through parallel evolution. Fossils have been uncovered from western U.S. from Oregon to Southern California and Nebraska, and also from Eurasia from France to Mongolia.

Merycoidodon ("ruminating teeth") is an extinct genus of herbivorous artiodactyl of the family Merycoidodontidae, more popularly known by the name Oreodon ("hillock teeth"). It was endemic to North America during the Middle Eocene to Middle Miocene (46—16 mya) existing for approximately .

Subhyracodon (Latin: "below the genus Hyracodon") is an extinct genus of hornless rhinocerotids.

Dermotherium is a genus of fossil mammals closely related to the living colugos, a small group of gliding mammals from Southeast Asia. Two species are recognized: D. major from the Late Eocene of Thailand, based on a single fragment of the lower jaw, and D. chimaera from the Late Oligocene of Thailand, known from three fragments of the lower jaw and two isolated upper molars. In addition, a single isolated upper molar from the Early Oligocene of Pakistan has been tentatively assigned to D. chimaera. All sites where fossils of Dermotherium have been found were probably forested e

Yantaromyrmex is an extinct genus of ants first described in 2013. Members of this genus are in the subfamily Dolichoderinae of the family Formicidae, known from Middle Eocene to Early Oligocene fossils found in Europe. The genus currently contains five described species, Y. constrictus, Y. geinitzi, Y. intermedius, Y. mayrianum and Y. samlandicus. The first specimens were collected in 1868 and studied by Austrian entomologist Gustav Mayr, who originally placed the fossils in other ant genera until the fossils were reviewed and subsequently placed into their own genus. These ants are small, me

Behemotops (from the Biblical monster Behemoth, by Linnaeus and others believed to be a hippo) is an extinct genus of herbivorous marine mammal. It lived from the Early Oligocene (Rupelian) through the Late Oligocene (33.9 mya—23 Mya), existing for approximately . It is the most primitive known desmostylian, believed to be close to the ancestry of all other desmostylians.

Leptomeryx is an extinct genus of artiodactyl that lived in North America during the middle Eocene through early Miocene. One of the earliest ruminants, it belongs to the extinct family Leptomerycidae, which is related to today's chevrotains. Most fossils were found in the badlands of the Midwestern United States in sedimentary rocks of the White River Group, in the Brule and Chadron formations. Additional remains have been reported from southern Canada and Mexico. The genus was scientifically described in 1853 by Joseph Leidy and includes several species.

Otarocyon ("large eared dog") is an extinct genus of the Borophaginae subfamily of canids native to North America. It lived during the Oligocene epoch, about 33.3—20.6 Ma (million years ago). Fossils have been found only in Montana, Wyoming, and South Dakota.

Sunkahetanka is an extinct monospecific genus of the Hesperocyoninae subfamily of early canids native to North America. It lived during the Oligocene, 30.8—26.3 Ma, existing for approximately . In form, it was intermediate between the small Cynodesmus and the later Enhydrocyon, the first hypercarnivorous, "bone-cracking", canid.

Philotrox is an extinct monospecific genus of the Hesperocyoninae subfamily of early canids native to North America. It lived during the Oligocene, 30.8—26.3 Ma, existing for approximately . In form, it was intermediate between the small Cynodesmus and the later Enhydrocyon, the first hypercarnivorous, "bone-cracking", canid.

Eolates ("dawn Lates") is an extinct genus of prehistoric lates perch from the Paleogene of Europe. It contains three species, two marine and one freshwater, known from the early-middle Eocene and Late Oligocene. left|thumb|Specimen of E. gracilis The following species are known: