List of largest prehistoric carnivorans

The largest prehistoric animals include both vertebrate and invertebrate species. Many of them are described below, along with their typical range of size (for the general dates of extinction, see the link to each). Many species mentioned might not actually be the largest representative of their clade due to the incompleteness of the fossil record and many of the sizes given are merely estimates since no complete specimen have been found. Their body mass, especially, is largely conjecture because soft tissue was rarely fossilized. Generally the size of extinct species was subject to energetic and biomechanical constraints.

Non-mammalian synapsids (Synapsida)

Caseasaurs (Caseasauria)

The herbivorous ''Alierasaurus'' was the largest caseid and the largest amniote to have lived at the time, with an estimated length around . '' Cotylorhynchus hancocki'' is also large, with an estimated length and weight of at least and more than .

Edaphosaurids (Edaphosauridae)

The largest edaphosaurids were ''Lupeosaurus'' at long and ''Edaphosaurus'', which could reach even more than in length.

Sphenacodontids (Sphenacodontidae)

The biggest carnivorous synapsid of Early Permian was ''Dimetrodon'', which could reach and . The largest members of the genus ''Dimetrodon'' were also the world's first fully terrestrial apex predators.

Tappenosauridae

The Middle Permian ''Tappenosaurus'' was estimated at in length, nearly as large as the largest dinocephalians.

Therapsids (Therapsida)

Anomodonts (Anomodontia)

The plant-eating dicynodont '' Lisowicia bojani'' is the largest-known of all non-mammalian synapsids, at about long, tall, and in body mass.

Dinocephalians (Dinocephalia)

Among the largest carnivorous non-mammalian synapsids was the dinocephalian ''Anteosaurus'', which was long, and weighed . Fully grown ''Titanophoneus'' from the same family Anteosauridae likely had a skull of long. Another enormous dinocephalian was the Late Permian ''Eotitanosuchus'' (a possible synonym to ''Biarmosuchus''). Adult specimens could reach in length and over in weight.

Gorgonopsians (Gorgonopsia)

'' Inostrancevia latifrons'' is the largest known gorgonopsian, with a skull length of more than , a total length approaching and a mass of . ''Rubidgea atrox'' is the largest African gorgonopsian, with skull of nearly long. Other large gorgonopsians include ''Dinogorgon'' with skull of ~ long, ''Leontosaurus'' with skull of almost long, and ''Sycosaurus'' with skull of ~ long.

Therocephalians (Therocephalia)

The largest of therocephalians is ''Scymnosaurus'', which reached a size of the modern hyena.

Non-mammalian cynodonts (Cynodontia)

* The largest known non-mammalian cynodont is '' Scalenodontoides'', a traversodontid, which had a maximum skull length of approximately based on a fragmentary specimen.
* '' Paceyodon davidi'' was the largest of morganucodontans, cynodonts close to mammals. It is known by a right lower molariform in length, which is bigger than molariforms of all other morganucodontans.
* The largest known docodont was ''Castorocauda'', almost in length.

Mammals (Mammalia)

Non-therian mammals

Gobiconodonts (Gobiconodonta)

The largest gobiconodont and the largest well-known Mesozoic mammal was ''Repenomamus''. The known adult of ''Repenomamus giganticus'' reached a total length of around and an estimated mass of . With such parameters it surpassed in size several small theropod dinosaurs of the Early Cretaceous. '' Gobiconodon'' was also a large mammal, it weighed , had a skull of in length, and had in presacral body length.

Multituberculates (Multituberculata)

The largest multituberculate ''Taeniolabis taoensis'' is the largest non-therian mammal known, at a weight possibly exceeding .

Monotremes (Monotremata)

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* The largest known monotreme (egg-laying mammal) ever was the extinct long-beaked echidna species known as ''Murrayglossus'', known from a couple of bones found in Western Australia. It was the size of a sheep, weighing probably up to .
* The largest known ornithorhynchid is ''Obdurodon tharalkooschild'', it was even larger than -long ''Monotrematum sudamericanum''.
* ''Kollikodon'' was likely the largest monotreme in Mesozoic. Its body length could be up to a .

Metatherians (Metatheria)

* The largest non-marsupial metatherian was '' Thylacosmilus'', weigh , one estimate suggesting even . Proborhyaenid ''Proborhyaena gigantea'' is estimated to weigh over and possibly reached . ''Australohyaena'' is another large metatherian, weighing up to .A. M. Forasiepi, M. Judith Babot, and N. Zimicz. 2014. Australohyaena antiqua (Mammalia, Metatheria, Sparassodonta), a large predator from the Late Oligocene of Patagonia. Journal of Systematic Palaeontology 13(6):503-525 DOI: 10.1080/14772019.2014.926403
* Stagodontid mammal ''Didelphodon'' was one of the largest Mesozoic metatherians and all Cretaceous mammals. Its skull could reached over in length and a weight of complete animal was .

Marsupials (Marsupialia)

* The largest known marsupial, and the largest metatherian, is the extinct ''Diprotodon'', about long, standing tall and weighing up to . Fellow vombatiform '' Palorchestes azael'' was similar in length being around , with body mass estimates indicating it could exceed .
* The largest known carnivorous marsupial was '' Thylacoleo carnifex''. Measurements taken from a number of specimens show they averaged in weight.
* The largest known kangaroo was an as yet unnamed species of ''Macropus'', estimated to weigh , larger than the largest known specimen of ''Procoptodon'', which could grow up to and weigh . Some species from the genus ''Sthenurus'' were similar in size or a bit larger than the extant grey kangaroo (''Macropus giganteus'').
* The largest potoroid ever recorded was ''Borungaboodie'', which was nearly 30% bigger than the largest living species and weighted up to .

Non-placental eutherians

Cimolestans (Cimolesta)

The largest known cimolestan is '' Coryphodon'', high at the shoulder, long and up to of mass. ''Barylambda'' was also a huge mammal, at . '' Wortmania'' and ''Psittacotherium'' from the group Taeniodonta were among the largest mammals of the Early Paleocene. Lived as soon as half a million years after K–Pg boundary, ''Wortmania'' reached in body mass. ''Psittacotherium'', which appeared two million years later, reached .

Leptictids (Leptictida)

The largest leptictid ever discovered is '' Leptictidium tobieni'' from the Middle Eocene of Germany. It had a skull long, head with trunk long, and tail long. Close European relatives from the same family Pseudorhyncocyonidae had skulls of in length.

Even-toed ungulates (Artiodactyla)

* The largest known land-dwelling artiodactyl was ''Hippopotamus gorgops'' with a length of , a height of , and a weight of .
* ''Daeodon'' and similar in size and morphology ''Paraentelodon''
were the largest-known entelodonts that ever lived, at long and high at the shoulder. The huge ''Andrewsarchus'' from the Eocene of Inner Mongolia had skull long though the taxonomy of this genus is disputive.

* The largest of Bovinae as well as the largest bovid was '' Bison latifrons''. It reached a weight from to , in length, shoulder height of , and had horns that spanned . The North American '' Bison antiquus'' reached up to long, tall, weight of , and horn span of . The African ''Pelorovis'' reached in weight and had bony cores of the horns about long. Another enormous bovid, the african giant buffalo (''Syncerus antiquus'') reached in length from muzzle to the end of the tail, in height at the withers, in height at the hindquarters, and the distance between the tips of its horns was as large as . Aside from local populations and subspecies of extant species, such as the gaur population in Sri Lanka, European bison in British Isles, Caucasian wisent and Carpathian wisent, the largest modern extinct bovid is aurochs (''Bos primigenius'') with an average height at the shoulders of in bulls and in cows, while aurochs populations in Hungary had bulls reaching . The kouprey (''Bos sauveli''), reaching in shoulder height, has existed since the Middle Pleistocene and is also considered to be possibly extinct.
* The long-legged ''Megalotragus'' is possibly the largest known alcelaphine bovid, bigger than the extant wildebeest. The tips of horns of ''M. priscus'' were located at a distance of about from each other.

* The extinct cervid Irish elk (''Megaloceros giganteus'') reached over in height, in mass and could have antlers spanning up to across, about twice the maximum span for a moose's antlers. The giant moose (''Cervalces latifrons'') reached high and was twice as heavy as the Irish elk but its antler span at was smaller than that of ''Megaloceros''.Oxworth Books. pp. 111, 126, 247–250. (1998) North American stag-moose ('' Cervalces scotti'') reached in length and a weight of .
* The largest known giraffid, aside from the extant giraffe, is ''Sivatherium'', with a body weight of .
* The largest protoceratid was '' Synthetoceras'', it reached long and in mass.
* The largest known wild suid to ever exist was ''Kubanochoerus gigas'', having measured up to and stood around tall at the shoulder. ''Megalochoerus'' could be similar in size, possibly weighing or .
* The largest camelid was '' Titanotylopus'' from the Miocene of North America. It possibly reached and a shoulder height of over . The Syrian camel ('' Camelus moreli'') was twice as big as the modern camels. It was at the shoulder and tall. '' Camelops'' had legs to be 20% longer than that of Dromedary, and was about tall at the shoulder and weighed about .

Cetaceans (Cetacea)

* The largest of known Eocene archeocete whales was '' Basilosaurus'' at in length.
* The largest prehistoric sperm whale, or toothed whale was '' Livyatan melvillei'' weighing in at about 57 tonnes (63 short tons).
* The largest squalodelphinid was ''Macrosqualodelphis'' at in length.
* Some Neogene rorquals were comparable in size to modern huge relatives. ''Parabalaenoptera'' was estimated to be about the size of the modern gray whale, about long. Some balaenopterids perhaps rivaled the blue whale in terms of size, though other studies disagree that any baleen whale grew that large in the Miocene.

Odd-toed ungulates (Perissodactyla)

* The largest known perissodactyl, and the second largest land mammal (see '' Palaeoloxodon namadicus'') of all time was the hornless rhino '' Paraceratherium''. The largest individual known was estimated at tall at the shoulders, in length from nose to rump, and in weight.
* Some prehistoric horned rhinos also grew to large sizes. The biggest '' Elasmotherium'' reached up to long, high and weighed . Such parameters make it the largest rhino of the Quaternary. Woolly rhinoceros (''Coelodonta antiquitatis'') of the same time reached or , at the shoulder height and in length.
* ''Metamynodon'', an amynodontid, reached in length, comparable to ''Hippopotamus'' in measurement and shape.
* The giant tapir ('' Tapirus augustus'') was the largest tapir ever, at about and tall at the shoulders. Earlier, this mammal was estimated even bigger, at tall, and assigned to the separate genus ''Megatapirus''.
* One of the biggest chalicotheres was ''Moropus''. It stood about tall at the shoulder.
* Late Eocene perissodactyls from the family Brontotheriidae attained huge sizes. The North American ''Megacerops'' (also known as ''Brontotherium'') reached tall at the shoulders, in length, and in weight. ''Embolotherium'' from Asia was equal in size.
* The largest prehistoric horse was ''Equus giganteus'' of North America. It was estimated to grow to more than and at the shoulders. The largest anchitherine equid was ''Hypohippus'' at , comparable to large modern domestic horses. ''Megahippus'' is another large anchitheriine. With the body mass of it was much heavier than most of its close relatives.

Phenacodontids (Phenacodontidae)

The largest known phenacodontid is ''Phenacodus''. It was long and weighed up to .

Dinoceratans (Dinocerata)

The largest known dinoceratan was '' Eobasileus'' with skull length of , tall at the back and tall at the shoulder. Another huge animal of this group was '' Uintatherium'', with skull length of , tall at the shoulder, in length and , the size of a rhinoceros. Despite their large size, ''Eobasileus'' as well as ''Uintatherium'' had a very small brain.

Carnivores (Carnivora)

Caniformia

* The largest terrestrial mammalian carnivore and the largest known bear, as well as the largest known mammalian land predator of all time, was ''Arctotherium angustidens'', the South American short-faced bear. A humerus of ''A. angustidens'' from Buenos Aires indicates that the males of the species could have weighed and stood at least tall on their hind-limbs. Another huge bear was the giant short-faced bear (''Arctodus simus''), with the average weight of and the maximum recorded at . There is a guess that the largest individuals of this species could reached even larger mass, up to . The extinct cave bear (''Ursus spelaeus'') was also heavier than many recent bears. Largest males weighed as much as . ''Ailuropoda baconi'' from the Pleistocene was larger than the modern giant panda (''Ailuropoda melanoleuca'').
* The biggest odobenid and one of the biggest pinnipeds to have ever existed is '' Pontolis magnus'', with skull length of (twice as large as the skulls of modern male walruses) and more than in total body length. Only the modern males of elephant seals ('' Mirounga'') reaches the similar sizes.
The second largest prehistoric pinniped is '' Gomphotaria pugnax'' with the skull length of nearly .

* One of the largest of prehistoric otariids is ''Thalassoleon'', comparable in size to the biggest extant fur seals. An estimated weight of ''T. mexicanus'' is no less than .

* The biggest known mustelid to ever exist was likely the giant otter, ''Enhydriodon''. It exceeded in length, and would have weighed in at around , much larger than any other known mustelid, living or extinct. There were other giant otters, like ''Siamogale'', at around and ''Megalenhydris'', which was larger than a modern-day giant river otter. ''Megalictis'' was the largest purely terrestrial mustelid (although ''Enhydriodon'' had recently been mentioned as the largest mustelid that also happens to be a terrestrial predator). Similar in size to the jaguar, ''Megalictis ferox'' had even wider skull, almost as wide as of the black bear. ''Megalictis'' had a powerful bite force, allowing it to eat large prey and crush bones, as modern hyenas and jaguars can. Another large-bodied mustelid was the superficially cat-like ''Ekorus'' from the Miocene of Africa. At almost , the long-legged ''Ekorus'' was about the size of a wolf and filling a similar to leopards ecological niche before big cats came to the continent. Other huge mustelids include '' Perunium'' and hypercarnivorous ''Eomellivora'', both from the Late Miocene.
* The heaviest procyonid was possibly South American ''Chapalmalania''. It reached in body length with a short tail and , comparable in size to an American black bear (''Ursus americanus''). Another huge procyonid was ''Cyonasua'', which weighted about , about the same size as a medium-sized dog.
* The largest canid of all time was ''Epicyon haydeni'', which stood tall at the shoulder, had a body length of and weighed , with the heaviest known specimen weighing up to . The extinct dire wolf (''Aenocyon dirus'') reached in length and weighed between . The largest wolf (''Canis lupus'') subspecies ever existed in Europe is the '' Canis lupus maximus'' from the Late Pleistocene of France. Its long bones are 10% larger than those of extant European wolves and 20% longer than those of ''C. l. lunellensis''. The Late Pleistocene Italian wolf was morphometrically close to ''C. l. maximus''.
* The largest bear-dog was a species of ''Pseudocyon'' weighing around , representing a very large individual.

Feliformia

* The largest nimravid was probably '' Quercylurus major'' as its fossils suggest it was similar in size to the modern-day brown bear and was scansorial. In 2021, ''Eusmilus'' was declared as the largest of the holplophonine nimravids, reaching the weight of nearly , comparable to a small African lion. However, the largest ''Hoplophoneus'' was estimated at .
* The biggest saber-toothed cats are '' Amphimachairodus kabir'' and ''Smilodon populator'', with the males possibly reaching and respectively. Another contender for the largest felid of all time is '' Machairodus''. ''M. horribilis'' from China was estimated at while the North American ''M. lahayishupup'' weighed up to . ''Xenosmilus'' was also a huge cat. It reached around long and weighed around .
* The heaviest known pantherine felids are the Ngangdong tiger (''Panthera tigris soloensis''), which are estimated to have weighed up to , the American lion (''Panthera atrox''), weighing up to Merriam, J. C. & Stock, C. 1932: The Felidae of Rancho La Brea. Carnegie Institution of Washington Publications 442, 1–231. and the Eurasian cave lion ('' Panthera spelaea''), weighing up to . Being the ancestor of the modern jaguar, '' Panthera gombaszoegensis'' was much larger, up to in maximum weight.
* Some extinct feline felids also surpassed their modern relatives in size. The Eurasian giant cheetah (''Acinonyx pardinensis'') reached , approximately twice as large as the modern cheetah. The North American '' Pratifelis'' was larger than the extant cougar.
* The largest barbourofelid was '' Barbourofelis fricki'', with the shoulder height of .
* The largest viverrid known to have existed is '' Viverra leakeyi'', which was around the size of a wolf or small leopard at .
* The largest known fossil hyena is ''Pachycrocuta'', estimated at at the shoulder and weight. Another huge hyena with mass over is the cave hyena. It is actually a subspecies of the African spotted hyena, which is at 10% smaller than the extinct cave hyena.
* The percrocutid feliform, ''Dinocrocuta'', was two or even three times as large as the extant spotted hyena, .
* The extinct giant fossa (''Cryptoprocta spelea'') had a body mass in range from to , much larger than the modern fossa weighs (up to for adult males).

Hyaenodonts (Hyaenodonta)

The largest hyaenodont was ''Simbakubwa'' at . Another giant hyaenodont, ''Megistotherium'' reached and had a skull of in length.

Oxyaenids (Oxyaenidae)

The largest known oxyaenid was '' Sarkastodon'' weighing in at .

Mesonychians (Mesonychia)

Some mesonychians reached a size of a bear. Such large were '' Mongolonyx'' from Asia and ''Ankalagon'' from North America. Another large mesonychian is ''Harpagolestes'' with a skull length of a half a meter in some species.

Bats (Chiroptera)

Found in Quaternary deposits of South and Central Americas, '' Desmodus draculae'' had a wingspan of and a body mass of up to . Such proportions make it the largest vampire bat that ever evolved.

Hedgehogs, gymnures, shrews, and moles (Eulipotyphla)

The largest known animal of the group Eulipotyphla was ''Deinogalerix'', measuring up to in total length, with a skull up to long.

Rodents (Rodentia)

* Several of the extinct South American dinomyids were much bigger than the modern rodents. ''Josephoartigasia monesi'' was the largest-known rodent of all time, approximately weighing an estimated . ''Phoberomys pattersoni'' weighed . Both ''Josephoartigasia'' and ''Phoberomys'' reached about tall at the shoulder. Another huge dinomyid, '' Telicomys gigantissimus'' had a minimal weight of .
* '' Amblyrhiza inundata'' from the family Heptaxodontidae was a massive animal, it weighed .
* The largest beaver was the giant beaver ('' Castoroides'') of North America. It grew over 2 m in length and weighed roughly , also making it one of the largest rodents to ever exist.

Rabbits, hares, and pikas (Lagomorpha)

The biggest known prehistoric lagomorph is Minorcan giant lagomorph ''Nuralagus rex'' at .

Primates (Primates)

* The largest known primate as well as the largest hominid of all time was '' Gigantopithecus blackii'', standing tall and weighing . However In 2017, new studies suggested a body mass of for this primate. Another giant hominid was '' Meganthropus palaeojavanicus'' at in body height, although it is known from very poor remains.
* During the Pleistocene, some archaic humans were close in sizes or even larger than early modern humans. Neanderthals ('' Homo neanderthalensis'') reached and in average weight for males and females, respectively, larger than the parameters of modern humans (''Homo sapiens'') ( and for males and females, respectively). A tibia from Kabwe (Zambia) indicates an indeterminate ''Homo'' individual of possibly in height. It was one of the tallest humans of the Middle Pleistocene and noticeably large even compared to recent humans. The tallest ''Homo sapiens'' individuals from the Middle Pleistocene of Spain reached and for males and females, respectively. Some ''Homo erectus'' could be as large as tall and in weight.
* The largest known Old World monkey is the prehistoric baboon, with a male specimen of ''Dinopithecus'' projected to weigh an average of and up to . It exceeds the maximum weight record of the chacma baboon, the largest extant baboon. One source projects a specimen of ''Theropithecus oswaldi'' to have weighed .
* The largest known New World monkey was ''Cartelles'', which is studied as specimen of ''Protopithecus'', weighing up to . ''Caipora bambuiorum'' is another large species, weighing up to .
* The largest omomyids were '' Macrotarsius'' and '' Ourayia'' from the Middle Eocene. Both reached in weight.
* Some prehistoric lemuriform primates grew to huge sizes as well. ''Archaeoindris'' was a sloth lemur that lived in Madagascar and weighed , as large as an adult male gorilla. ''Palaeopropithecus'' from the same family was also heavier than most modern lemurs, at .Crowley, B.E., & Godfrey, L.R. (2019).
Strontium Isotopes Support Small Home Ranges for Extinct Lemurs
. Frontiers in Ecology and Evolution, 7, 490. doi: 10.1002/ajp.20817 '' Megaladapis'' is another large extinct lemur at in length and an average body mass of around . Other estimates suggest but its still much larger than any extant lemur.

Elephants, mammoths, and mastodons (Proboscidea)

* The largest known land mammal ever was a proboscidean called '' Palaeoloxodon namadicus'' which weighed about and measured about tall at the shoulder. The largest individuals of the steppe mammoth of Eurasia (''Mammuthus trogontherii'') estimated to reach at the shoulders and in weight. ''Stegodon zdanskyi'', the biggest species of '' Stegodon'', was in body mass. Another one enormous proboscidean is '' Stegotetrabelodon syrticus'', over in height and in weight. The Columbian mammoth (''Mammuthus columbi'') was about tall at the shoulder but didn't weigh as much as other huge mammoths. Its average mass was with one unusually large specimen about . Columbian mammoths had very long tusks. The largest known mammoth tusk, long, belonged to this species.
* The largest mammutid was the Neogene ''Mammut borsoni''. The biggest specimen reached tall and weighed about . This species also had the longest tusks, long from basis to tip along the curve.
* ''Deinotherium'' was the largest proboscidean in Deinotheriidae family. Bones retrieved in Crete confirm the existence of specimen tall at the shoulders and more than in weight.

Sea cows (Sirenia)

According to reports, Steller's sea cows have grown to long as adults, much larger than any extant sirenians. The weight of Steller's sea cows is estimated to be .

Arsinoitheres (Arsinoitheriidae)

The largest known arsinoitheriid was '' Arsinoitherium''. ''A. zitteli'' would have been tall at the shoulders, and long. ''A. giganteum'' reached even larger size than ''A. zitteli.''

Hyraxes (Hyracoidea)

Some of the prehistoric hyraxes were extremely large compared to modern small relatives. The largest hyracoid ever evolved is '' Titanohyrax ultimus''. With the mass estimation in rage of to over it was close in size to Sumatran rhinoceros. Another enormous hyrax is ''Megalohyrax'' which had skull of in length and reached the size of tapir. More recent ''Gigantohyrax'' was three times as large as the extant relative ''Procavia capensis'', although it is noticeably smaller than earlier ''Megalohyrax'' and ''Titanohyrax''.

Desmostylians (Desmostylia)

The largest known desmostylian was a species of ''Desmostylus'', with skull length of and comparable in size to the Steller's sea cow.

''Paleoparadoxia'' is also known as one of the largest desmostylians, with body length of .

Armadillos, glyptodonts and pampatheres (Cingulata)

The largest cingulate known is '' Doedicurus'', at long, high and reaching a mass of approximately . The largest species of '' Glyptodon'', ''Glyptodon clavipes'', reached in length and in weight.

Anteaters and sloths (Pilosa)

The largest known pilosan ever was ''Megatherium'', a ground sloth with an estimated average weight of and a height of which is almost as big as the African bush elephant. Several other sloths grew to large sizes as well, such as ''Eremotherium'', but none as large as ''Megatherium''.

Astrapotherians (Astrapotheria)

Some of the largest known astrapotherians weighed about , including the genus '' Granastrapotherium'' and some species of ''Parastrapotherium'' (''P. martiale''). The skeleton remains suggests that the species '' Hilarcotherium miyou'' was even larger, with a weight of .

Litopterns (Litopterna)

The largest known litoptern was ''Macrauchenia'', which had three hoofs per foot. It was a relatively large animal, with a body length of around .

Notoungulates (Notoungulata)

The largest notoungulate known of complete remains is ''Toxodon''. It was about in body length, and about high at the shoulder and resembled a heavy rhinoceros. Although is not complete, the preserved fossils suggests that ''Mixotoxodon'' were the most massive member of the group, with a weight about .

Pyrotherians (Pyrotheria)

The largest mammal of the South American order Pyrotheria was ''Pyrotherium