The largest prehistoric animals include both
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.
The herbivorous Alierasaurus was the largest
caseid and the largest
amniote to have lived at the time, with an estimated length around 6–7 m (20–23 ft).Cotylorhynchus hancocki is also large, with an estimated length and weight of at least 6 m (20 ft) and more than 500 kg (1,100 lb).
The biggest carnivorous synapsid of
Early Permian was Dimetrodon, which could reach 4.6 m (15 ft) and 250 kg (550 lb). The largest members of the genus Dimetrodon were also the world's first fully terrestrial
Paceyodon davidi was the largest of
morganucodontans, cynodonts close to mammals. It is known by a right lower molariform 3.3 mm (0.13 in) in length, which is bigger than molariforms of all other morganucodontans.
Photo-reconstruction of Murrayglossus hacketti (Zaglossus hacketti) by paleoartist
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 30 kg (66 lb).
The largest known
marsupial, and the largest
metatherian, is the extinct Diprotodon, about 3 m (9.8 ft) long, standing 2 m (6 ft 7 in) tall and weighing up to 2,786 kg (6,142 lb). Fellow
vombatiformPalorchestes azael was similar in length being around 2.5 m (8.2 ft), with body mass estimates indicating it could exceed 1,000 kg (2,200 lb).
The largest known carnivorous marsupial was Thylacoleo carnifex. Measurements taken from a number of specimens show they averaged 101 to 164 kg (223 to 362 lb) in weight.
The largest known
kangaroo was an as yet unnamed species of Macropus, estimated to weigh 274 kg (604 lb), larger than the largest known specimen of Procoptodon, which could grow up to 2 m (6 ft 7 in) and weigh 230 kg (510 lb). Some species from the genus Sthenurus were similar in size or a bit larger than the extant
grey kangaroo (Macropus giganteus).
potoroid ever recorded was Borungaboodie, which was nearly 30% bigger than the largest living species and weighted up to 10 kg (22 lb).
The largest of
Bovinae as well as the largest
bovid was Bison latifrons. It reached a weight from 1,250 kg (2,760 lb) to 2,000 kg (4,400 lb), 4.75 m (15.6 ft) in length, shoulder height of 2.31 m (7.6 ft), and had horns that spanned 2.13 m (7 ft 0 in). The North American Bison antiquus reached up to 4.6 m (15 ft) long, 2.27 m (7.4 ft) tall, weight of 1,588 kg (3,501 lb), and horn span of 1 m (3.3 ft). The African Pelorovis reached 2 t (2.2 short tons) in weight and had bony cores of the horns about 1 m (3 ft 3 in) long. Another enormous bovid, the
african giant buffalo (Syncerus antiquus) reached 3 m (9.8 ft) in length from muzzle to the end of the tail, 1.85 m (6.1 ft) in height at the
withers, 1.7 m (5.6 ft) in height at the hindquarters, and the distance between the tips of its horns was as large as 2.4 m (7 ft 10 in). 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 155–180 cm (61–71 in) in bulls and 135–155 cm (53–61 in) in cows, while aurochs populations in Hungary had bulls reaching 155–160 cm (61–63 in). The
kouprey (Bos sauveli), reaching 1.7–1.9 m (5 ft 7 in – 6 ft 3 in) 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 1.2 m (3 ft 11 in) from each other.
cervidIrish elk (Megaloceros giganteus) reached over 2.1 m (7 ft) in height, 680 kg (1,500 lb) in mass and could have antlers spanning up to 4.3 m (14 ft) across, about twice the maximum span for a moose's antlers. The
giant moose (Cervalces latifrons) reached 2.1 to 2.4 m (6.9 to 7.9 ft) high and was twice as heavy as the Irish elk but its antler span at 2.5 m (8.2 ft) was smaller than that of Megaloceros. North American
stag-moose (Cervalces scotti) reached 2.5 metres (8.2 ft) in length and a weight of 708.5 kilograms (1,562 lb).
The largest known
giraffid, aside from the extant giraffe, is Sivatherium, with a body weight of 1,250 kg (2,760 lb).
The largest known wild
suid to ever exist was Kubanochoerus gigas, having measured up to 500 kg (1,100 lb) and stood around 1 m (3 ft 3 in) tall at the shoulder.Megalochoerus could be similar in size, possibly weighing 303 kg (668 lb) or 526 kg (1,160 lb).
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 4.8 m (15.7 ft) tall at the shoulders, 7.4 m (24.3 ft) in length from nose to rump, and 17 t (18.7 short tons) in weight.
giant tapir (Tapirus augustus) was the largest tapir ever, at about 623 kg (1,373 lb) and 1 m (3.3 ft) tall at the shoulders. Earlier, this mammal was estimated even bigger, at 1.5 m (4.9 ft) tall, and assigned to the separate genus Megatapirus.
The largest prehistoric horse was Equus giganteus of North America. It was estimated to grow to more than 1,250 kg (1.38 short tons) and 2 m (6 ft 7 in) at the shoulders. The largest
anchitherine equid was Hypohippus at 403 to 600 kg (888 to 1,323 lb), comparable to large modern
domestic horses.Megahippus is another large anchitheriine. With the body mass of 266.2 kg (587 lb) it was much heavier than most of its close relatives.
The largest known
dinoceratan was Eobasileus with skull length of 102 cm (40 in), 2.1 m (6 ft 11 in) tall at the back and 1.5 m (4 ft 11 in) tall at the shoulder. Another huge animal of this group was Uintatherium, with skull length of 76 cm (30 in), 1.5 m (4 ft 11 in) tall at the shoulder, 4 m (13 ft) in length and 2.25 t (2.48 short tons), the size of a
rhinoceros. Despite their large size, Eobasileus as well as Uintatherium had a very small brain.
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 1,588–1,749 kg (3,501–3,856 lb) and stood at least 3.4 m (11 ft) tall on their hind-limbs. Another huge bear was the giant short-faced bear (Arctodus simus), with the average weight of 625 kg (1,378 lb) and the maximum recorded at 957 kg (2,110 lb). There is a guess that the largest individuals of this species could reached even larger mass, up to 1,200 kg (2,600 lb). The extinct
cave bear (Ursus spelaeus) was also heavier than many recent bears. Largest males weighed as much as 1,000 kg (2,200 lb).Ailuropoda baconi from the Pleistocene was larger than the modern
giant panda (Ailuropoda melanoleuca).
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 295–318 kg (650–701 lb).
The biggest known
mustelid to ever exist was likely the giant otter, Enhydriodon. It exceeded 3 m (9.8 ft) in length, and would have weighed in at around 200 kg (440 lb), much larger than any other known mustelid, living or extinct. There were other giant otters, like Siamogale, at around 50 kg (110 lb) 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 44 kg (97 lb), 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
hypercarnivorousEomellivora, both from the
procyonid was possibly South American Chapalmalania. It reached 1.5 metres (4.9 ft) in body length with a short tail and 150 kilograms (330 lb), comparable in size to an
American black bear (Ursus americanus). Another huge procyonid was Cyonasua, which weighted about 15–25 kg (33–55 lb), about the same size as a medium-sized dog.
The largest known fossil
hyena is Pachycrocuta, estimated at 90–100 cm (35–39 in) at the shoulder and 190 kg (420 lb) weight. Another huge hyena with mass over 100 kg (220 lb) is the
cave hyena. It is actually a subspecies of the African
spotted hyena, which is at 10% smaller than the extinct cave hyena.
percrocutid feliform, Dinocrocuta, was two or even three times as large as the extant spotted hyena, 160 or 240 kg (350 or 530 lb).
Found in Quaternary deposits of South and Central Americas, Desmodus draculae had a wingspan of 0.5 m (20 in) and a body mass of up to 60 g (2.1 oz). Such proportions make it the largest
vampire bat that ever evolved.
Hedgehogs, gymnures, shrews, and moles (Eulipotyphla)
The largest beaver was the
giant beaver (Castoroides) of North America. It grew over 2 m in length and weighed roughly 90 to 125 kg (198 to 276 lb), also making it one of the largest rodents to ever exist.
archaic humans were close in sizes or even larger than
early modern humans.
Neanderthals (Homo neanderthalensis) reached 77.6 kg (171 lb) and 66.4 kg (146 lb) in average weight for males and females, respectively, larger than the parameters of modern humans (Homo sapiens) (68.5 kg (151 lb) and 59.2 kg (131 lb) for males and females, respectively). A
Zambia) indicates an indeterminate Homo individual of possibly 181.2 cm (71.3 in) 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 194 cm (76 in) and 174 cm (69 in) for males and females, respectively. Some Homo erectus could be as large as 185 cm (73 in) tall and 68 kg (150 lb) in weight.
The largest known land mammal ever was a
proboscidean called Palaeoloxodon namadicus which weighed about 22 t (24.3 short tons) and measured about 5.2 m (17.1 ft) tall at the shoulder. The largest individuals of the
steppe mammoth of
Eurasia (Mammuthus trogontherii) estimated to reach 4.5 m (14.8 ft) at the shoulders and 14.3 t (15.8 short tons) in weight.Stegodon zdanskyi, the biggest species of Stegodon, was 13 t (14.3 short tons) in body mass. Another one enormous proboscidean is Stegotetrabelodon syrticus, over 4 m (13 ft) in height and 11 to 12 t (12.1 to 13.2 short tons) in weight. The
Columbian mammoth (Mammuthus columbi) was about 4 m (13.1 ft) tall at the shoulder but didn't weigh as much as other huge mammoths. Its average mass was 9.5 t (10.5 short tons) with one unusually large specimen about 12.5 t (13.8 short tons). Columbian mammoths had very long tusks. The largest known mammoth tusk, 4.9 m (16 ft) long, belonged to this species.
mammutid was the Neogene Mammut borsoni. The biggest specimen reached 4.1 m (13 ft) tall and weighed about 16 t (17.6 short tons). This species also had the longest tusks, 5.02 m (16.5 ft) 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 4.1 m (13 ft) tall at the shoulders and more than 14 t (15.4 short tons) in weight.
Sea cows (Sirenia)
According to reports,
Steller's sea cows have grown to 8 to 9 m (26 to 30 ft) long as adults, much larger than any
extantsirenians. The weight of Steller's sea cows is estimated to be 8–10 t (8.8–11.0 short tons).
The largest known
pilosan ever was Megatherium, a ground sloth with an estimated average weight of 3.8 t (4.2 short tons) and a height of 6 m (20 ft) 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.
The largest known
litoptern was Macrauchenia, which had three hoofs per foot. It was a relatively large animal, with a body length of around 3 m (9.8 ft).
notoungulate known of complete remains is Toxodon. It was about 2.7 m (8 ft 10 in) in body length, and about 1.5 m (4 ft 11 in) high at the shoulder and resembled a heavy rhinoceros. Although incomplete, the preserved fossils suggests that Mixotoxodon were the most massive member of the group, with a weight about 3.8 t (4.2 short tons).
The largest mammal of the South American order
Pyrotheria was Pyrotherium at 2.9–3.6 m (9 ft 6 in – 11 ft 10 in) in length and 1.8–3.5 t (4,000–7,700 lb) in weight.
Megalania skeletal reconstruction on Melbourne Museum steps
mosasaurs are the largest-known animals within the
Squamata. The largest-known mosasaur is likely Mosasaurus hoffmanni, estimated at more than 17 m (56 ft) in length, however these estimations are based on heads and total body length ratio 1:10, which is unlikely for Mosasaurus, and probably that ratio is about 1:7. Another giant mosasaur is Tylosaurus, estimated at 10–14 m (33–46 ft) in length. Another large mosasaur is Hainosaurus bernardi (could be synonymous to Tylosaurus). It was once estimated at 17 and 15 m (56 and 49 ft) in length, but later estimates put it at around 12.2 m (40 ft).
The largest known land lizard is probably
megalania (Varanus priscus) at 7 m (23 ft) in length. As extant relatives, megalania could have been venomous and in that case this lizard was also the largest venomous vertebrate ever evolved. However, maximum size of this animal is subject to debate.
Turtles, tortoises and close relatives (Pantestudines)
The largest known turtle ever was Archelon ischyros at 5 m (16 ft) long and 2,200 kg (4,900 lb). Possible second-largest sea turtle was Protostega at 3.9 m (13 ft) in total body length. There is even a larger specimen of this genus from Texas estimated at 4.2 m (14 ft) in total length. Another huge prehistoric sea turtle is the Late Cretaceous Gigantatypus, estimated at over 3.5 m (11 ft) in length.Psephophorus terrypratchetti from the Eocene attained 2.3–2.5 m (7.5–8.2 ft) in body length.
trionychid ever recorded is indeterminate specimen GSP-UM 3019 from the
Middle Eocene of
Pakistan. Bony carapace of GSP-UM 3019 is 120 cm (3.9 ft) long and 110 cm (3.6 ft) wide indicates the total carapace diameter (with soft margin) about 2 m (6.6 ft).Drazinderetes tethyensis from the same formation had a bony carapace 80 cm (2.6 ft) long and 70 cm (2.3 ft) wide. Another huge trionychid is North American Axestemys byssinus at over 2 m (6.6 ft) in total length.
meiolaniid was Meiolania. Meiolania platyceps had a carapace 100 cm (3.3 ft) long and probably reached over 3 m (9.8 ft) in total body length. An unnamed Late Pleistocene species from
Queensland was even larger, up to 200 cm (6.6 ft) in carapace length.Ninjemys oweni reached 100 cm (3.3 ft) in carapace length and 200 kg (440 lb) in weight.
The largest known
plesiosauroid was an indeterminate specimen possibly belonging to Aristonectes (identified as cf. Aristonectes sp.), with a body length of 11–11.9 metres (36–39 ft) and body mass of 10.7–13.5 metric tons (11.8–14.9 short tons). Another long plesiosauroid was Albertonectes at 11.2–11.6 metres (37–38 ft).Thalassomedon rivaled it in size, with its length at 10.86–11.6 m (35.6–38.1 ft). Other large plesiosauroids are Styxosaurus and Elasmosaurus. Both reached some more than 10 m (33 ft) in length.Hydralmosaurus (previously synonymized with Elasmosaurus and Styxosaurus) reached 9.44 m (31.0 ft) in total body length. In past, Mauisaurus was considered to be more than 8 m (26 ft) in length, but later it was determined as nomen dubium.
Late CretaceousAegisuchus is the main contender for the title of the largest
crocodylomorph ever recorded. It reached 15 m (49 ft) in length by the lower estimate and as much as 22 m (72 ft) by the upper estimate, although a length of over 15 m is likely an overestimate.
caiman and likely the largest
crocodylian was Purussaurus brasiliensis estimated at 11–13 m (36–43 ft). According to another information, maximum estimate measure 11.4 m (37 ft) and almost 7.8 t (8.6 short tons) in length and in weight respectively. Another giant caiman was Mourasuchus. Various estimates suggest the biggest specimens reached 9.47 m (31.1 ft) in length and 8.5 t (9.4 short tons) in weight or 4.7–5.98 m (15.4–19.6 ft) in body length.
Pliocene species of Quinkana known from partial remains may have reached up to 6 m (20 ft) in length, although other species (known from
Pleistocene) are smaller with length just about 3 m (9.8 ft). It is not only the largest
mekosuchian (some studies reject it from this group) but also it could have been
Australia's largest Pliocene predator.Paludirex is another large mekosuchian with length over 4 m (13 ft).
pholidosaurids reached giant sizes. In the past, the Sarcosuchus imperator was believed to be the largest crocodylomorph, with initial estimates proposing a length of 12 m (39 ft) and a weight of 8 t (8.8 short tons). However, recent estimates have now shrunk to a length of 9 to 9.5 m (29.5 to 31.2 ft) and a weight of 3.5 to 4.3 metric tons (3.9 to 4.7 short tons). Related to Sarcosuchus, Chalawan thailandicus could reached more than 10 m (33 ft) in length, although other estimates suggest 7–8 m (23–26 ft).
The largest terrestrial
notosuchian crocodylomorph was very likely the
MiocenesebecidBarinasuchus, with a skull of 95–110 cm (37–43 in) long, comparable in size to the 104 cm (41 in)-long skull of Daspletosaurus. Various estimates suggest a possible length of Barinasuchus at 6–7.5 m (20–25 ft).
The largest known
ichthyosaur and the largest
marine reptile was the
Late TriassicShastasaurus sikanniensis at 21 m (69 ft) in length and 81.5 t (180,000 lb) in weight. In April 2018, paleontologists announced the discovery of a previously unknown ichthyosaur that may have reached lengths of 26 m (85 ft) making it one of the largest animals known, rivaling some
blue whales in size. Another, larger ichthyosaur was found in 1850 in
Aust. Its remains seemed to surpass the measurements of the other ichthyosaur, but the researchers commented that the remains were too fragmentary for a size estimate to be made. Another huge ichthyosaur was Shonisaurus popularis at 15 m (49 ft) in length and 29.7 t (65,000 lb) in weight. The largest
Middle Triassic ichthyosaur as well as the largest animal of that time was Cymbospondylus youngorum at 14 to 17.65 m (45.9 to 57.9 ft) in length and 14.7 to 135.8 t (32,000 to 299,000 lb) in weight.
sauropod, Maraapunisaurus fragillimus (previously known as Amphicoelias fragillimus), is a contender for the largest-known dinosaur in history. It has been estimated at 58–60 m (190–197 ft) in maximum length and 122,400 kg (269,800 lb) in weight. Unfortunately, the fossil remains of this dinosaur have been lost. More recently, it was estimated at 35–40 m (115–131 ft) in length and 80–120 t (180,000–260,000 lb) in weight.
Known from the incomplete and now disintegrated remains, the
Late CretaceousBruhathkayosaurus matleyi was an anomalously large sauropod. Informal estimations suggested as huge parameters as 45 m (148 ft) in length and 139–220 t (306,000–485,000 lb) in weight. More accurate estimation suggests 37 m (121 ft) and 95 t (209,000 lb) but it still much heavier than most other sauropods.
Other huge sauropods include Argentinosaurus, Alamosaurus, and Puertasaurus with estimated lengths of 30–33 m (98–108 ft) and weights of 50–80 t (55–88 short tons).Patagotitan was estimated at 37 m (121 ft) in length and 57 t (63 short tons) in average weight, and was similar in size to Argentinosaurus and Puertasaurus. Giant sauropods like Supersaurus, Sauroposeidon, and Diplodocus probably rivaled them in length but not in weight.Dreadnoughtus was estimated at 49 t (108,000 lb) in weight and 26 m (85 ft) in length but the most complete individual was immature when it died.Turiasaurus is considered of being the largest dinosaur from Europe, with an estimated length of 30 m (98 ft) and a weight of 50 t (55 short tons). However, with lower estimate at 21 m (69 ft) and 30 t (66,000 lb) it was smaller than Portuguese Lusotitan that reached 24 m (79 ft) in length and 34 t (75,000 lb) in weight.
Many large sauropods are still unnamed and may rival the current record holders:
Archbishop", a large brachiosaur that was discovered in 1930. The animal was reported to get a scientific paper published by the end of 2016.
Brachiosaurus nougaredi is yet another large brachiosaur from Early Cretaceous North Africa. The remains have been lost, but the sacrum drawing remains. They suggest a
sacrum of almost 1.3 m (4.3 ft) long, making it the largest dinosaur sacrum discovered so far, except those of Argentinosaurus and Apatosaurus.
In 2010, the femur of a large sauropod was discovered in France. The femur suggests an animal that grew to immense sizes.
theropod as well as the largest terrestrial (or possibly semi-aquatic) predator yet known is Spinosaurus aegyptiacus, with the largest specimen known estimated at 12.6–18 m (41–59 ft) in length and around 7–20.9 t (8–23 short tons) in weight. New estimates published in 2014 and 2018, based on a more complete specimen supported that Spinosaurus could reach lengths of 15 to 16 meters (49 to 52 ft). The latest estimates suggest a weight of 6.4 to 7.5 metric tons (7.1 to 8.3 short tons). The
White Rock spinosaurid had vertebrae comparable in dimensions to Spinosaurus, it was likely a huge theropod with a length over 10 m (33 ft).
pachycephalosaur was the nominate Pachycephalosaurus. Previously claimed to be at 7 m (23 ft) in length, it was later estimated about 4.5 metres (14.8 ft) long and a weight of about 450 kilograms (990 lb).
The widest known wingspan of any flight-capable bird was Pelagornis sandersi with a wingspan of 7.3 m (24 ft), and a body weight of 21.7 kg (48 lb). The heaviest flight-capable bird was the giant teratorn, Argentavis magnificens which had a somewhat-smaller wingspan at around 5.09–6.5 m (16.7–21.3 ft) but was far heavier, with accepted maximums around 70–72 kg (154–159 lb).
One of the largest
enantiornitheans was Enantiornis, with a length in life of around 78.5 cm (30.9 in), hip height of 34 cm (13 in), weight of 6.75 kg (14.9 lb), and wingspan comparable to some of the modern gulls, around 1.2 m (3 ft 11 in).Gurilynia was the largest
Mesozoic bird from
Mongolia, with a length of 53 cm (21 in), hip height of 23.2 cm (9.1 in), and weight of 2.1 kg (4.6 lb).
Late CretaceousAvisaurus was almost as large as Enantiornis. It had a wingspan around 1.2 m (3 ft 11 in), a length of 72 cm (28 in), hip height of 31.5 cm (12.4 in), and weight of 5.1 kg (11 lb). Even larger could be the Soroavisaurus. One
tibiotarsus (PVL-4033) indicates an animal with a length of 80 cm (31 in), hip height of 35 cm (14 in), and weight of 7.25 kg (16.0 lb).Mirarce was comparable in size to a
turkey, much larger than most of other enantiornitheans.
Gargantuavis is the largest known bird of the
Mesozoic, a size ranging between the
cassowary and the
ostrich, and a mass of 140 kg (310 lb) like modern ostriches. In 2019 specimens MDE A-08 and IVPP-V12325 were measured at 1.8 m (5 ft 11 in) in length, 1.3 m (4 ft 3 in) in hip height, and 120 kg (260 lb) in weight.
Large individuals of Gastornis (also known as Diatryma) reaged up to 2 m (6 ft 7 in) in height. Weight of Gastornis ranges from 100 kg (220 lb) to 156 kg (344 lb) and sometimes to 180 kg (400 lb) for European specimens and from 160 kg (350 lb) to 229 kg (505 lb) for North American.
The largest known-ever
Cariamiforme and largest
phorusrhacid or "terror bird" (highly predatory, flightless birds of America) was Brontornis, which was about 175 cm (69 in) tall at the shoulder, could raise its head 2.8 m (9 ft 2 in) above the ground and could have weighed as much as 400 kg (880 lb). The immense phorusrhacid Kelenken stood 3 m (9.8 ft) tall with a skull 716 mm (28.2 in) long (460 mm (18 in) of which was beak), had the largest head of any known bird. South American Phorusrhacos stood nearly 2.4 to 2.7 meters (7 ft 10 in to 8 ft 10 in) tall, and probably weighed nearly 130 kilograms (290 lb), as much as a male
ostrich. The largest North American phorusrhacid is Titanis, which is about 2.5 m (8 ft 2 in) tall, as tall as a forest elephant.
The tallest known bird was the
South Island giant moa (Dinornis robustus), part of the moa family of
New Zealand that went extinct about 500 years ago. It stood up to 3.7 m (12 ft) tall, and weighed approximately half as much as a large elephant bird due to its comparatively slender frame.
The largest bird in the fossil record may be the extinct
elephant birds (Vorombe, Aepyornis) of Madagascar, which were related to the ostrich. They exceeded 3 m (9.8 ft) in height and 500 kilograms (1,100 lb) in weight.
The largest pigeon relative known was the
dodo (Raphus cucullatus), possibly exceeding 1 m (3.3 ft) in height and weighing as much as 28 kg (62 lb), although recent estimates have indicated that an average wild dodo weighed much less at approximately 10.2 kg (22 lb).
Pheasants, turkeys, gamebirds and allies (Galliformes)
The largest known
cormorant was the
spectacled cormorant of the North Pacific (Phalacrocorax perspicillatus), which became extinct around 1850 and averaged around 6.4 kg (14 lb) and 1.15 m (3 ft 9 in).
The largest known darter was Giganhinga with estimated weight about 17.7 kg (39 lb), earlier study even claims 25.7 kg (57 lb).
The largest known grebe, the
Atitlán grebe (Podylimbus gigas), reached a length of about 46–50 centimetres (18–20 in).
Bony-toothed birds (Odontopterygiformes)
The largest known of the
Odontopterygiformes— a group which has been variously allied with Procellariiformes, Pelecaniformes and Anseriformes and the largest flying birds of all time other than Argentavis were the huge Pelagornis, Cyphornis, Dasornis, Gigantornis and Osteodontornis. They had a wingspan of 5.5–6 m (18–20 ft) and stood about 1.2 m (3 ft 11 in) tall. Exact size estimates and judging which one was largest are not yet possible for these birds, as their bones were extremely thin-walled, light and fragile, and thus most are only known from very incomplete remains.
The largest known
penguin of all time was Palaeeudyptes klekowskii of
Antarctica, its body length (tip of the bill to tip of the tail) is estimated about 2.02 m (6 ft 8 in) and body weight is estimated about 116.21 kg (256.2 lb). Another large penguin is Anthropornis nordenskjoeldi of
New Zealand and
Antarctica. Its body length is estimated 1.99 m (6 ft 6 in) and was 97.8 kg (216 lb) in weight. There is also an estimate that one remain of Anthropornis can reach that body length of 2.05 m (6 ft 9 in) and 108 kg (238 lb) in weight. Similar in size were the
New Zealand giant penguin (Pachydyptes pondeorsus) with a height of 1.4 to 1.6 m (4 ft 7 in to 5 ft 3 in) and weighing possibly around 80 to 100 kg (180 to 220 lb) and over, and Icadyptes salasi at 1.5 m (4 ft 11 in) tall.
The largest known temnospondyl amphibian is Prionosuchus, which grew to lengths of 9 m (30 ft). Another huge temnospondyl was Mastodonsaurus giganteus at 6 m (20 ft) long. Unnamed species of temnospondyl from
Lesotho is partial, but possible body length estimation is 7 m (23 ft).
The largest known
placoderm was the giant predatory Dunkleosteus. The largest and most well known species was D. terrelli, which grew almost 9 m (29.5 ft) in length and 4 t (4.4 short tons) in weight. Its filter feeding relative, Titanichthys, may have rivaled it in size.Titanichthys reached a length of 7 m (23 ft) though in older paper it was estimated at 7.5 m (25 ft).
Species in the extinct genus Otodus were huge. A giant
shark, Otodus megalodon is by far the biggest
mackerel shark ever known. Most estimates of megalodon's size extrapolate from teeth, with maximum length estimates up to 10–20.3 m (33–67 ft) and average length estimates of 10.5 m (34 ft). Due to fragmentary remains, there have been many contradictory size estimates for megalodon, as they can only be drawn from fossil teeth and vertebrae.: 87  Mature male megalodon may have had a body mass of 12.6 to 33.9 metric tons (13.9 to 37.4 short tons), and mature females may have been 27.4 to 59.4 metric tons (30.2 to 65.5 short tons), assuming that males could range in length from 10.5 to 14.3 m (34 to 47 ft) and females 13.3 to 17 m (44 to 56 ft). Related to megalodon, Otodus angustidens and O. chubutensis reached the large sizes too. Each was estimated at 9.3 m (31 ft) and 12.2 m (40 ft), respectively.
The largest known
eugeneodont is an as-yet unnamed species of Helicoprion discovered in Idaho. The specimens suggest an animal that possibly exceeded 12 m (39 ft) in length. Another fairly large eugeneodont is Parahelicoprion. Being more slimmer than Helicoprion, it reached nearly the same size, possibly up to 12 m (39 ft) in length. Both had the largest sizes among the animals of
Not only the largest known
rhizodont, but also the largest lobe-finned fish was the 6–7 m (20–23 ft) long Rhizodus. Another large rhizodonts were Strepsodus with estimated length around 3–5 m (9.8–16.4 ft) and Barameda estimated at 3–4 m (9.8–13.1 ft) in length.
Mongolarachne jurassica is the largest described fossil
spider, with the total body length of female is approximately 24.6 mm (0.97 in) while the front legs reach about 56.5 mm (2.22 in) in length.Dinodiplura ambulacra had larger body length, combined length of carapace and opisthosoma reaches 26.15 mm (1.030 in).
The largest of prehistoric
whipscorpions and possibly the largest-known whipscorpion ever discovered was Mesoproctus. An unnamed species M. sp. had a carapace of 32.5 mm (1.28 in) in length and 16 mm (0.63 in) in width, comparable or even larger than the extant Mastigoproctus have.
Retifacies probably reached up to 55 cm (22 in).Tegopelte is another one example of large non-trilobite artiopod, reached 280 mm (11 in) long and was the largest of the
Burgess Shale bilaterians, surpassing all other benthic organisms by at least twice.
The largest known
myriapod by far was Arthropleura. Measuring 2.5 metres (8 ft 2 in) long and 50 centimetres (20 in) wide. Some specimens could have been even larger, up to 2.63 metres (8 ft 8 in) in length and 50 kilograms (110 lb) in weight.
Wingless early insect Carbotriplura had body length about 103 millimetres (4.1 in) without tail filaments.
Ringed worms (Annelida)
Websteroprion is the largest known fossil
eunicidanannelid, with estimated length ranges 0.42–8.3 m (1 ft 5 in – 27 ft 3 in), however comparison with closely related extant taxa indicates length around 1–2 m (3 ft 3 in – 6 ft 7 in). It also had the biggest
scolecodonts of any prehistoric
polychaete, up to 13.2 mm (0.52 in) in length and possibly larger.
The largest and longest known of
nautiloids was Endoceras giganteum with a shell length of 5.73 m (18.8 ft). There is a record of individual whose shell length had reached 9.14 m (30.0 ft), but it is doubtful.
The largest known
ammonite was Parapuzosia seppenradensis. A partial fossil specimen found in
Germany had a shell diameter of 1.95 m (6 ft 5 in), but the
living chamber was incomplete, so the estimated shell diameter was probably about 3.5 m (11 ft) and weighed about 705 kg (1,554 lb) when it was alive. However, later study estimates shell diameter up to around 2 m (6 ft 7 in).
Squids, octopuses, cuttlefishes and allies (Neocoleoidea)
OctopodEnchoteuthis melanae (considered as specimen of Tusoteuthis longa) had mantle length up to 2 metres (6 ft 7 in), comparable to the modern-day
giant squid. Previously, this taxon is considered as animal like giant squid, with total length including arms over 10 metres (33 ft). However, considering other fossil relatives, total length including arms is estimated to be around 3 metres (9.8 ft).
Longest specimens of Trepassia wardae (also known as Charnia wardi) reached 185 cm (73 in) in length.Charnia masoni is known from specimens as small as only 1 cm (0.39 in), up to the largest specimens of 66 cm (26 in) in length.
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