Prehistoric placental genera

Paraceratherium is an extinct genus of hornless rhinocerotoids belonging to the family Paraceratheriidae. It is one of the largest terrestrial mammals that has ever existed and lived from the Early to Late Oligocene epoch (34–23 million years ago). The first fossils were discovered in what is now Pakistan, and remains have been found across Eurasia between China and the Balkans. Paraceratherium means "near the hornless beast", in reference to Aceratherium, the genus in which the type species P. bugtiense was originally placed.

Megatherium ( ; from Greek () 'great' + () 'beast') is an extinct genus of large ground sloths endemic to South America that lived from the Early Pliocene through the end of the Late Pleistocene. It is best known for the elephant-sized, type species Megatherium americanum, primarily known from the Pampas, but ranging southwards to northernmost Patagonia and northwards to southern Bolivia during the late Middle Pleistocene and Late Pleistocene. Various other species have been described, including those belonging to the Andean subgenus Pseudomegatherium, which range in size from comparable to M.

Deinotherium is an extinct genus of large, elephant-like proboscideans that lived from the Middle Miocene until the end of the Early Pleistocene. Although its appearance is reminiscent of modern elephants, Deinotherium differered considerably from modern elephants in several anatomical details: it possessed a notably more flexible neck, proportionally more slender limbs, tapir-like teeth, as well as tusks which grew down and curved back from the lower jaw (mandible), and lacked tusks growing from the upper jaw. Several species of Deinotherium grew larger than modern elephants, not uncommonly r

Glyptodon (; ) is a genus of glyptodont, an extinct group of large, herbivorous armadillos that lived from the Pliocene, around 3.2 million years ago, to the early Holocene, around 11,000 years ago, in South America. It is one of, if not the, best-known genera of glyptodont. Glyptodon has a long and storied past, being the first named extinct cingulate and the type genus of the subfamily Glyptodontinae. Fossils of Glyptodon have been recorded as early as 1814 from Pleistocene aged deposits from Uruguay, though many were incorrectly referred to the ground sloth Megatherium by early paleontologi

Stegodon (from the Ancient Greek στέγω (stégō), meaning "to cover", and ὀδούς (odoús), meaning "tooth", named for the distinctive ridges on the animal's molars) is an extinct genus of proboscidean, related to elephants. It was originally assigned to the family Elephantidae along with modern elephants but is now placed in the extinct family Stegodontidae. Like elephants, Stegodon had teeth with plate-like lophs that are different from those of more primitive proboscideans like gomphotheres and mammutids. Fossils of the genus are known from Africa and across much of Asia, as far southeast as Tim

Hipparion is an extinct genus of three-toed, medium-sized equine belonging to the extinct tribe Hipparionini, which lived about 10-5 million years ago. While the genus formerly included most hipparionines, the genus is now more narrowly defined as hipparionines from Eurasia spanning the Late Miocene. Hipparion was a mixed-feeder who ate mostly grass, and lived in the savannah biome. Hipparion evolved from Cormohipparion, and went extinct due to environmental changes like cooling climates and decreasing atmospheric carbon dioxide levels.

Gomphotherium (; "nail beast" for its double set of straight tusks) is an extinct genus of gomphothere proboscidean from the Neogene of Eurasia, Africa and North America. It is the most diverse genus of gomphothere, with over a dozen valid species. The genus is probably paraphyletic, and ancestral to other gomphothere genera.

Moeritherium ("Lake Moeris' beast") is an extinct genus of basal proboscideans from the Eocene of North and West Africa. The first specimen was discovered in strata from the Fayum fossil deposits of Egypt. It was named in 1901 by Charles William Andrews, who suggested that it was an early proboscidean, perhaps ancestral to mastodons, although subsequent workers considered it everything from a relative of manatees to a close relative of both clades' common ancestor. Currently, Moeritherium is seen as a proboscidean that, while fairly basal, diverged before the split between elephantiforms and d

Platybelodon (possibly "shovel tooth") is an extinct genus of amebelodontid proboscidean mammal, distantly related to modern-day elephants. Fossils are known from middle Miocene strata from parts of Asia and the Caucasus. The first specimens of Platybelodon, consisting of a partial skull, a nearly complete lower jaw, and multiple disarticulated remains, were discovered in the Tchokrak beds of north Caucasus, in the summer of 1927. The following year, Russian palaeontologist Alexey Borissiako described them, giving them the name Platybelodon danovi (now the type species of the genus). Several a

Uintatherium is an extinct genus of dinoceratan mammal that lived during the Eocene epoch. Two species are currently recognized: U. anceps is found in the United States and lived during the early to middle Eocene (50.5–37 million years ago), while U. insperatus is found in China and lived during the middle and late Eocene (48–37 million years ago). The first fossils of Uintatherium were recovered from the Fort Bridger Basin and were initially believed to belong to a new species of brontothere. Several previously recognized species, as well as genera such as Edward Drinker Cope's Loxolophodon a

Macrauchenia ("long llama", based on the now-invalid llama genus, Auchenia, from Greek "big neck") is an extinct genus of large ungulate native to South America from the Pliocene or Middle Pleistocene to the end of the Late Pleistocene. It was one of the last surviving members of the extinct order Litopterna, a group of South American native ungulates distinct from the two orders which contain all living ungulates which had been present in South America since the early Cenozoic, over 60 million years ago, prior to the arrival of living ungulates in South America around 2.5 million years ago as

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.

Arsinoitherium (Arsinoe II's beast) is an extinct genus of paenungulate mammals belonging to the extinct order Embrithopoda. It is related to elephants, sirenians, and hyraxes. Arsinoitheres were superficially rhinoceros-like herbivores that lived during the Late Eocene and the Early Oligocene of North Africa from 36 to 30 million years ago, in areas of tropical rainforest and at the margin of mangrove swamps. A species described in 2004, A. giganteum, lived in Ethiopia about 27 million years ago.

Mesohippus (Greek: / meaning "middle" and / meaning "horse") is an extinct genus of early horse. It lived 37 to 32 million years ago in the Early Oligocene. Like many fossil horses, Mesohippus was common in North America. Its shoulder height is estimated at 60 cm.

Toxodon (from Ancient Greek τόξον (tóxon), meaning "bow", and ὀδούς (odoús), meaning "tooth", in reference to the curvature of the teeth) is an extinct genus of large ungulate native to South America from the Pliocene to the end of the Late Pleistocene. Toxodon is a member of Notoungulata, an order of extinct South American native ungulates distinct from the two living ungulate orders that had been indigenous to the continent for over 60 million years since the early Cenozoic, prior to the arrival of living ungulates into South America around 2.5 million years ago during the Great American Int

Propalaeotherium was an early genus of perissodactyl endemic to Europe and Asia during the early Eocene. There are currently six recognised species within the genus, with P. isselanum as the type species (named by Georges Cuvier in 1824).

Plesiadapis (near Adapis) is an extinct genus of mammal closely related to primates, found in North America and western Europe. The type species, P. tricuspidens, was described in 1877 by François Louis Paul Gervaise, based on a partial left mandible (lower jaw) uncovered in France. Fourteen valid species have since been named.

Palaeoloxodon is an extinct genus of elephant. It originated in Africa during the Early Pleistocene, and expanded into Eurasia at the beginning of the Middle Pleistocene. Palaeoloxodon contains the largest known species of elephants, with mature bulls over tall at the shoulders and over in weight, representing among the largest land mammals ever, including the African Palaeoloxodon recki, the European straight-tusked elephant (Palaeoloxodon antiquus) and the South Asian Palaeoloxodon namadicus. P. namadicus has been suggested to be the largest known land mammal by some authors based on extrapo

Eohippus is an extinct genus of small equid ungulates. The only species is E. angustidens, which was long considered a species of Hyracotherium (now strictly defined as a member of the Palaeotheriidae rather than the Equidae). Its remains have been identified in North America and date to the Early Eocene (Ypresian stage).

Eurotamandua ("european Tamandua") is an extinct genus of mammal from extinct family Eurotamanduidae that lived during the middle Eocene.

Merychippus is an extinct proto-horse of the family Equidae that was endemic to North America during the Miocene, 15.97–5.33 million years ago. It had three toes on each foot and is the first horse known to have grazed.

Phiomia (after the Ancient Greek phiom "lake", an ancient name for the Fayum) is an extinct genus of basal elephantiform proboscidean that lived in what is now Northern Africa during the Late Eocene to Early Oligocene some 37–30 million years ago. The type specimen of Phiomia, part of the mandible (lower jaw), was described in 1902 by Charles William Andrews and Hugh John Llewellyn. Unsure of its identity, they assigned it, tentatively, to the obsolete order Creodonta. Subsequently, it was recognised as a proboscidean. Briefly it was treated as a junior synonym of Palaeomastodon, but the two a

Miacis ("small point") is an extinct genus of placental mammals from clade Carnivoraformes, that lived in North America from the early to middle Eocene.

Megistotherium ("greatest beast") is an extinct genus of very large hyaenodont belonging to the family Hyainailouridae that lived in Africa and possibly Asia during the early-middle Miocene epoch. The first specimen, a near-complete skull, was discovered in 1963 by Robert J. G. Savage in Libya, and was kept at the Natural History Museum in London alongside postcrania discovered in the prior few years. In 1973, Savage described Megistotherium based on these elements, with the skull serving as the type specimen. It was later determined that the assigned postcrania actually came from an amphicyon

Eremotherium (from Greek for "steppe" or "desert" "beast": ἔρημος "steppe or desert" and θηρίον "beast") is an extinct genus of giant ground sloth in the family Megatheriidae. Eremotherium lived in southern North America, Central America, and northern South America. It was one of the largest sloths, with a body size comparable to elephants, weighing around and measuring about long, slightly larger than its close relative Megatherium.

Phenacodus (Greek: "deception" (phenax), "tooth' (odus)) is an extinct genus of mammals from the late Paleocene through middle Eocene, about 55 million years ago. It is one of the earliest and most primitive of the ungulates, typifying the family Phenacodontidae and the order Perissodactyla.

Mylodon is an extinct genus of ground sloth belonging to the family Mylodontidae, known from southern South America. With a total length of 3 to 4 m and a body mass of 1-2 tonnes, it is one of the largest mylodontids (though it was considerably exceeded in size by the mylodontid Lestodon).

Prolagus is an extinct genus of lagomorph. Over 20 species have been named, and the genus was abundant and widespread in Europe during the Neogene. However, by the end of the Middle Pleistocene, it was confined to a single species, the Sardinian pika (P. sardus), on Corsica, Sardinia, and their surrounding islands, where it survived into historical times. In North Africa and Western Asia, the genus is known from the Miocene and Pliocene. The scientific name may mean "before hares" or "primitive hares" (pro- meaning "before" and lagos meaning "hare"). Its taxonomy is disputed, with it either be

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

Pliohippus (from Ancient Greek πλείων (pleíon), meaning "more", and ἵππος (híppos), meaning "horse") is an extinct genus of Equidae, the horse family. Pliohippus arose in the middle Miocene, around 15 million years ago. The long and slim limbs of Pliohippus reveal a quick-footed steppe animal. While some specimens have one toe per leg, others have three (the main toe and two non-functional side toes).

Palaeomastodon ("ancient mastodon") is an extinct genus of basal proboscideans from the Oligocene of North Africa. The first specimen discovered was recovered from strata belonging to the Fayum fossil deposits of Egypt. It was described and named in 1901 by Charles Williams Andrews, who named its type species, P. beadnelli, after a colleague. Multiple species have been named since, though have either been reassigned to Phiomia or synonymised with P. beadnelli. Three (possible) unnamed taxa are known from Ethiopia and Libya. All remains are from strata that date to 33–27 million years ago.

Oxyaena ("sharp hyena") is an extinct genus of placental mammals from extinct subfamily Oxyaeninae within extinct family Oxyaenidae, that lived in Europe, Asia and North America (with most specimens being found in Colorado) during the early Eocene.

Nuralagus is an extinct genus of leporid (the family of rabbits and hares), with a single species, Nuralagus rex, described in 2011. It lived on Menorca, one of the Balearic Islands in the western Mediterranean during the Pliocene epoch. It is the largest known lagomorph to have ever existed, with an estimated weight of , nearly double the weight of the average Flemish Giant rabbit. It likely went extinct at the Pliocene-Pleistocene transition when Mallorca and Menorca were united as one island, letting the mammalian fauna of Mallorca, including the goat-like ungulate Myotragus, colonize Nural

Thalassocnus is an extinct genus of semiaquatic ground sloths from the Miocene and Pliocene of the Pacific South American coast. It is monotypic within the subfamily Thalassocninae. The five species—T. antiquus, T. natans, T. littoralis, T. carolomartini, and T. yuacensis—represent a chronospecies, a population gradually adapting to marine life in one direct lineage. They are the only known aquatic sloths, but they may have also been adapted to a terrestrial lifestyle. They have been found in the Pisco Formation of Peru, the Tafna Formation of Argentina, and the Bahía Inglesa, Coquimbo, and Ho

Primelephas is a genus of Elephantinae that existed during the Miocene and Pliocene epochs. The name of the genus suggests 'first elephant'. These primitive elephantids are thought to be the common ancestor of Mammuthus, the mammoths, and the closely allied genera Elephas and Loxodonta, the Asian and African elephants, diverging some 4-6 million years ago. It had four tusks, which is a trait not shared with its descendants, but common in earlier proboscideans. The type species, Primelephas gomphotheroides, was described by Vincent Maglio in 1970, with the specific epithet indicating the fossil

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).

Megalonyx (Greek, "great-claw") is an extinct genus of ground sloths of the family Megalonychidae, native to North America. It evolved during the Pliocene Epoch and became extinct at the end of the Late Pleistocene, living from ~5 million to ~13,000 years ago. The type species, M. jeffersonii (also called '''Jefferson's ground sloth'''), the youngest and largest known species, measured about in length and weighed up to nearly .

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.

Eomanis ("dawn pangolin") is the earliest known true (and scaled) pangolin from extinct family Eomanidae (and extinct superfamily Eomanoidea) within suborder Eupholidota. It lived during the Eocene in Europe. Eomanis fossils found in the Messel Pit in Germany are very similar in size and anatomy to living pangolins of the genus Manis, indicating that pangolins have remained largely unchanged in morphology and behavior for 50 million years. However, unlike modern pangolins, its tail and legs did not bear scales. According to the stomach contents of the excellently preserved Messel specimens, Eo

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.

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.

Hippidion (meaning "little horse" in Ancient Greek) is an extinct genus of equine that lived in South America from the Late Pliocene to the end of the Late Pleistocene (Lujanian), between 2.5 million and 11,000 years ago. Hippidion arrived in South America along with many other animals of North American origin as part of the Great American Interchange. They were one of two lineages of equines native to South America during the Pleistocene epoch, alongside Equus (Amerhippus) neogeus. Hippidion ranged widely over South America, extending to the far south of Patagonia. Hippidion differs from livi

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:

Anancus is an extinct genus of "tetralophodont gomphothere" native to Afro-Eurasia, that lived from the Tortonian stage of the late Miocene until its extinction during the Early Pleistocene, roughly from 8.5–2 million years ago.

Astrapotherium ("lightning beast") is an extinct genus of large astrapotherian ungulate native to South America during the early-middle Miocene. It is the best known member of the group. The type species. A. magnum have been found in the Santa Cruz Formation in Argentina. Other fossils have been found in the Deseado, Sarmiento, and Aisol Formations of Argentina and Chile (Cura-Mallín Group).

Doedicurus, from Ancient Greek δοῖδυξ (doîdux), meaning "pestle" and oυρά (ourá), meaning "tail", is an extinct genus of glyptodont from South America containing one species, D. clavicaudatus. Glyptodonts are a member of the family Chlamyphoridae, which also includes some modern armadillo species, and they are classified in the superorder Xenarthra alongside sloths and anteaters. Being a glyptodont, it was a rotund animal with heavy armor and a carapace. Averaging at an approximate , it was one of the largest glyptodonts to have ever lived. Though glyptodonts were quadrupeds, large ones like D

Deinogalerix (from Ancient Greek, Deinos; "terrible/terror", + Galerix) is an extinct genus of gymnure which lived in Italy in the Late Miocene, 7-10 million years ago; gymnures belong to the subfamily Galericinae of the family Erinaceidae which also contain the hedgehogs, though extant gymnures and moonrats are fully hairy, without sharp quills. Deinogalerix is thought to have also lacked quills.

Cuvieronius is an extinct New World genus of gomphothere which ranged from southern North America to northwestern South America during the Pleistocene epoch. Reaching a shoulder height of and a body mass of , it was comparable in size to an Asian elephant. Cuvieronius inhabited subtropical and tropical latitudes in environments ranging from grasslands to tropical rainforest. Among the last gomphotheres along with the South American Notiomastodon, it became extinct as part of the end Pleistocene-extinction event, approximately 12-11,000 years ago, along with most other large mammals in the Amer

Parahippus ("near to horse"), is an extinct equid, a relative of modern horses, asses, and zebras. It lived from 24 to 17 million years ago, during the Miocene epoch. It was very similar to Miohippus, but slightly larger, at around tall, at the withers. Their fossils have been found in North America, primarily in the Great Plains region and Florida.

Plesiorycteropus, also known as the bibymalagasy or Malagasy aardvark, is a recently extinct genus of mammals from Madagascar. Upon its description in 1895, it was classified with the aardvark, but more recent molecular evidence instead suggests that it is most closely related to the tenrecs (a group extant on the island). Two species are currently recognized, the larger P. madagascariensis and the smaller P. germainepetterae. They probably overlapped in distribution, as subfossil remains of both species have been found in the same site.

Macrocranion is a genus of extinct mammal from the Eocene epoch of Europe and North America. Exceptional fossils have been found in the Messel Pit of Germany. Macrocranion species are often described as forest-floor predators, about the size of small squirrels but with longer limbs. The genus is represented at the Messel Pit site by two species, M. tupaidon and M. tenerum. thumb|right|Restoration of M. tenerum M. tupaiodon had woolly fur with no spikes. Although possibly an omnivore, fossil remains indicate the specimen had eaten fish near the time of its death. This small animal was approxi

Chriacus is an extinct genus of placental mammals that lived in what is now North America from the Paleocene and early Eocene epochs. In life, members of the genus may have looked something like a kinkajou or binturong, though they were not closely related to any living mammal. Like many early Cenozoic mammals, its relationships are uncertain, with possible affinities to ungulates or Ferae (carnivorans and their relatives).

Arctocyon (from Ancient Greek ἄρκτος (árktos), meaning "bear", and κύων (kúon), meaning "dog", and thus, "bear-dog") is an extinct genus of large placental mammals, part of the possibly polyphyletic family Arctocyonidae. The type species is A. primaevus, though up to five other species may be known. Fossils of Arctocyon have been found in Europe and North America. Arctocyon was originally named as a subgenus of the bear-dog Amphicyon, though was subsequently found to belong to a genus and family of its own. The relationship between arctocyonids and other placentals is unclear, with early class

Anchitherium (meaning near beast) is a genus of extinct equid with a three-toed hoof. thumb|left|Mandibles Anchitherium was a browsing (leaf eating) horse that originated in the early Miocene of North America, being found as far south as Panama, and subsequently dispersed to Europe and Asia, where it gave rise to the larger bodied genus Sinohippus. It was around high at the shoulder, and probably represented a side-branch of horse evolution that left no modern descendants.

thumb|Skull of P. ferox Peltephilus, the horned armadillo, is an extinct genus of armadillo xenarthran mammals that first inhabited Argentina during the Oligocene epoch, and became extinct in the Miocene epoch. Notably, the scutes on its head were so developed that they formed horns. Aside from the horned gophers of North America, it is the only known fossorial horned mammal.

Numidotherium (from Numidia, and Ancient Greek θηρίον (thēríon), meaning "beast") is an extinct genus of early proboscideans, discovered in 1984, that lived during the middle Eocene of North Africa some 46 million years ago. It was about tall at the shoulder and weighed about .

Palaeolagus ('ancient hare') is an extinct genus of lagomorph. Palaeolagus lived during the Eocene and Oligocene epochs of North America.

Sinonyx ("Chinese claw") is a genus of extinct, superficially wolf-like mesonychid mammals from the late Paleocene of China (about 56 million years ago). It is within the family Mesonychidae, and cladistic analysis of a skull of Sinonyx jiashanensis identifies its closest relative as Ankalagon. S. jiashanensis was discovered in Anhui province, China (, paleocoordinates ), in the Tuijinshan formation.

Desmostylus is an extinct genus of herbivorous mammal of the family Desmostylidae living from the Chattian stage of the Late Oligocene subepoch through the Late Miocene subepoch (28.4 mya–7.250 Mya) and in existence for approximately .

Megahippus is an extinct genus of large Anchitheriine horses found throughout the southern portion of the United States during the middle Miocene. The animal represents one of the latest low-crowned horses, overlapping in time with more derived high-crowned horses.