Eocene genus first appearances

Hyaenodon ("hyena-tooth") is an extinct genus of carnivorous placental mammals from the tribe Hyaenodontini, part of the subfamily Hyaenodontinae (which is within the family Hyaenodontidae), that belonged to the now extinct order Hyaenodonta. The genus was found lived in Eurasia and North America from the Middle Eocene to the Early Miocene, from 38 to 17 million years ago, existing for . Hyaenodon first evolved in Asia, probably evolving from Propterodon.

250px|right|thumb|Pagrus major|Red seabream (Pagrus major) 250px|right|thumb|Australasian snapper 250px|right|thumb|Red porgy Pagrus is a genus of marine ray-finned fishes belonging to the family Sparidae, which includes the seabreams and porgies. These fishes are found in the Western Pacific Ocean, Atlantic Ocean and Mediterranean Sea. They are esteemed food fishes which are targeted by commercial fisheries and are grown in aquaculture.

Archaeotherium (, meaning "ancient beast") is an extinct genus of entelodont artiodactyl endemic to North America during the Eocene and Oligocene epochs (35–28 mya). Archaeotherium fossils are most common in the White River Formation of the Great Plains, but they have also been found in the John Day Basin of Oregon and the Trans-Pecos area of Texas. Archaeotherium's fossils come from North America, between the Priabonian and Rupelian stages of the Eocene and Oligocene (35–28 million years ago). Up to fifteen species of Archaeotherium have been identified, which are divided into three subgenera

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.

Mesonyx ("middle claw") is an extinct genus of mesonychid, one of the families that is part of the extinct order Mesonychia. Fossils of the various species are found in Early to Late Eocene-age strata in the United States and Early Eocene-aged strata in China, 51.8—51.7 Ma (AEO).

Sarkastodon ("flesh-tearing tooth") is an extinct genus of placental mammals from the extinct subfamily Oxyaeninae within the extinct family Oxyaenidae. The genus lived in Asia (in today's China and Mongolia) during the middle Eocene and was the last known oxyaenid. The first fossil of Sarkastodon, part of a lower jaw, was discovered in 1928 in one of the Central Asiatic Expeditions. The second, consisting of the front of the skull and two partial lower jaws, was discovered by a surgeon, Dr. A. Z. Garber, in the final expedition, two years later. Recognised as a "relatively colossal" oxyaenid,

Barytherium (meaning "heavy beast") is a genus of an extinct genus of large primitive proboscideans that lived during the late Eocene and early Oligocene in North Africa. The type species is Barytherium grave, found at the beginning of the 20th century in Fayum, Egypt. Since then, more complete specimens have been found at Dor el Talha, Libya. More fossils were also discovered in 2011 in the Aidum area in Dhofar by Oman's Ministry of Heritage and Culture, which was named Barytherium omansi.

Miohippus (meaning "small horse") is an extinct genus of horse existing longer than most Equidae. It lived in what is now North America from 32 to 25 million years ago, during the late Eocene to late Oligocene. According to the Florida Museum of Natural History, Othniel Charles Marsh first believed Miohippus lived during the Miocene and thus named the genus using this incorrect conclusion. More recent research provides evidence that Miohippus actually lived during the Paleogene period.

Machaeroides ("dagger-like") is an extinct genus of sabre-toothed predatory placental mammals from the extinct subfamily Machaeroidinae within the extinct family Oxyaenidae, that lived in North America (Wyoming) from the early to middle Eocene.

Patriofelis ("father of cats") is an extinct genus of carnivorous placental mammals from the extinct subfamily Oxyaeninae within the extinct family Oxyaenidae, which lived from the early to middle Eocene, during the Bridgerian stage of NALMA. The first remains were discovered in 1869 by geologist Ferdinand Vandeveer Hayden, and the genus was named the following year by Joseph Leidy. Over the next few decades, additional specimens would be named from the same locality (or similar ones), many assigned to genera of their own or to separate species within Patriofelis. Now, only two are recognised:

Orohippus (from the Greek , 'mountain' and , 'horse') is an extinct equid that lived in the Eocene (about 50 million years ago). Its fossils have been unearthed in Oregon, Colorado, Utah, and Wyoming.

right|thumb|Ischnochiton spp. (unknown species) from South Africa thumb|Ischnochiton winckworthi from western India (Mumbai) Ischnochiton is a genus of polyplacophoran mollusc.

Daphoenus is an extinct genus of amphicyonids, a group colloquially known as "bear-dogs". It includes not just some of the best preserved material out of any amphicyonid, but also the earliest members of the family, first appearing in the middle Eocene and surviving into the Early Oligocene. The members of the genus are rather small compared to some of its later relatives, such as Amphicyon or Ysengrinia, ranging in size from comparable to a house cat to a small wolf. It was widely distributed across North America, with most of its remains being discovered in the White River Group of the Great

Limnocyon ("swamp dog") is an extinct paraphyletic genus of limnocyonin hyaenodonts that lived in North America during the middle Eocene. Fossils of this animal have been found in California, Utah and Wyoming.

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

Sinopa ("swift fox") is an extinct genus of placental mammals from extinct clade Sinopinae within extinct order Hyaenodonta, that lived in North America and Asia from the early to middle Eocene.

Bothriogenys is a genus of anthracotheres that lived in Eastern Africa during the Late Eocene to Early Oligocene.

Galecyon ("polecat-like dog") is an extinct genus of placental mammals from extinct order Hyaenodonta, that lived in Europe and North America (found in the Clarks Fork and Powder River basins of Wyoming) during the early Eocene.

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.

Hypertragulus is an extinct genus of hypertragulid ruminant endemic to North America. It lived from the Late Eocene to the Middle Miocene, living , existing for approximately .

Palaeogale is an extinct genus of carnivorous mammal known from the Late Eocene, Oligocene, and Early Miocene of North America, Europe, and Eastern Asia. A small carnivore often associated with the mustelids, Palaeogale might have been similar to living genets, civets, and linsangs.

Pyrocyon ("fire dog") is an extinct genus of small carnivorous placental mammals from extinct order Hyaenodonta, that lived in North America during the early Eocene. Fossils of Pyrocyon have been found in Wyoming and Colorado. Weight of Pyrocyon dioctetus has been estimated at around 2.6 kilograms.

Prionomyrmex is an extinct genus of bulldog ants in the subfamily Myrmeciinae of the family Formicidae. It was first described by Gustav Mayr in 1868, after he collected a holotype worker of P. longiceps in Baltic amber. Three species are currently described, characterised by their long mandibles, slender bodies and large size. These ants are known from the Eocene and Late Oligocene, with fossil specimens only found around Europe. It is suggested that these ants preferred to live in jungles, with one species assumed to be an arboreal nesting species. These ants had a powerful stinger that was

Afrotarsius is a primate found in the Paleogene of Africa. left|thumb|Afrasia from Asia and Afrotarsius from Africa exhibit similar morphology of their teeth and lived in the late middle Eocene, suggesting Stem group|stem simians dispersed from Asia to Africa around that time.|alt=Two molars, one of Afrotarsius (left) and one of Afrasia (right), are compared, with an Eocene map of the globe showing where each came from. In the lower left, a life reconstruction of Afrotarsius is shown. The first species to be named, Afrotarsius chatrathi, was named in 1985 on the basis of a single lower jaw fro

Palaeocarpilius is an extinct genus of crabs belonging to the family Carpiliidae. The type species of this genus is Palaeocarpilius macrocheilus.