Largest prehistoric animals

[15] The largest carnivorous non-mammalian synapsids was the dinocephalian Anteosaurus, which was 5–6 m (16–20 ft) long, and weighed 500–600 kg (1,100–1,300 lb).

[61] The larger of the two species of bibymalagasy (Plesiorycteropus madagascariensis), extinct tenrec relatives from Madagascar, is estimated to have weighed from 10 to 18 kilograms (21 to 40 lb).

[201] 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).

[243][246] More recent Gigantohyrax was three times as large as the extant relative Procavia capensis,[247] although it is noticeably smaller than earlier Megalohyrax and Titanohyrax.

[248] The largest known desmostylian was a species of Desmostylus, with skull length of 81.8 cm (32.2 in) and comparable in size to the Steller's sea cow.

[citation needed] The largest known pilosan is Eremotherium, a ground sloth with an estimated weight of up to 6.55 t (7.22 short tons) and a length of up to 6 m (20 ft),[252] which is as big as a bull African bush elephant.

[259] The largest freshwater turtle of all time was the Miocene podocnemid Stupendemys, with an estimated parasagittal carapace length of 2.86 m (9 ft 5 in) and weight of up to 1,145 kg (2,524 lb).

[393] 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.

[407] 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).

[426] Patagotitan was estimated at 37 m (121 ft) in length[427] and 57 t (63 short tons) in average weight,[428] and was similar in size to Argentinosaurus and Puertasaurus.

[433] Many large sauropods are still unnamed and may rival the current record holders: The largest-known thyreophoran was Ankylosaurus at 9 m (30 ft) in length and 6 tonnes (6.6 short tons) in weight.

Giant elephant birds exceeded 2.3 metres (7.5 ft) in height, and average a mass of 850 kg (1,870 lb)[472] The largest fowl was the mihirung Dromornis stirtoni of Australia.

This particular species of bird stood at 3.5 metres (11.5 ft) tall and average a mass of 450 kg (990 lb)[475] The largest known flightless neoave was the terror bird Paraphysornis brasiliensis of South America, the Brazilian terror bird exceeded 240 kg (530 lb) in mass,[476] One of the largest enantiornitheans was Enantiornis,[497] 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),[498] and wingspan comparable to some of the modern gulls, around 1.2 m (3 ft 11 in).

[507][481][508] Possibly flightless, the Miocene Garganornis ballmanni was larger than any extant members of Anseriformes, with 15.3–22.3 kg (34–49 lb) in body mass.

[521] Miomancalla howardi was the largest known charadriiform of all time, weighing approximately 0.6 kg (1.3 lb) more than the second-largest member, the great auk (Pinguinus impennis).

[527] The Pleistocene Teratornis merriami reached 13.7 kg (30 lb) and 2.94–3.38 m (9.6–11.1 ft) in wingspan, with lower size estimates still exceeding the largest specimens of California condor (Gymnogyps californianus).

[530] South American Phorusrhacos stood 2.4-2.7 m (7.9-8.8 ft) tall, and weighed nearly 130 kilograms (290 lb), as much as a male ostrich.

[532][533] The largest North American phorusrhacid was Titanis, which reached a height of approximately 2.5 m (8.2 ft),[534] slightly taller than an African forest elephant.

It stood up to 3.7 m (12 ft) tall,[544] and weighed approximately half as much as a large elephant bird due to its comparatively slender frame.

[545] MPLK-03, a tinamou specimen that existed during the Late Pleistocene in Argentina, possibly belongs to the modern genus Eudromia and surpacces extant E. elegans and E. formosa in size by 2.2–8% and 6–14%, respectively.

[545] With 450 kg (990 lb) in body mass, Pachystruthio dmanisensis from the lower Pleistocene of Crimea was the largest bird ever recorded in Europe.

[547] A possible specimen of Pachystruthio from the lower Pleistocene of Hebei Province (China) was about 300 kg (660 lb) in weight, twice heavier than the common ostrich (Struthio camelus).

[citation needed] 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.

[558] One of the heaviest penguins ever known is Kumimanu fordycei, with a body mass estimate of 148 to 159.7 kg (326 to 352 lb), derived from humerus measurements.

[559][560] The Eocene Anthropornis nordenskjoeldi is comparable in size, and was once estimated to reach lengths of 2.05 m (6 ft 9 in) and a weight of 108 kg (238 lb).

[566] The largest known diacectid, herbivorous Diadectes, was a heavily built animal, up to 3 m (9.8 ft) long, with thick vertebrae and ribs.

[636][637] Based on the findings of mouthparts, the Cambrian gilled lobopodian Omnidens amplus is estimated to have been 1.5 metres (4.9 ft).

[661] Tegopelte is another one example of large non-trilobite artiopod, reached 280 mm (11 in) long[662] and was the largest of the Burgess Shale bilaterians, surpassing all other benthic organisms by at least twice.

A nearly complete specimen of Isotelus rex from Manitoba attained a length over 70 cm (28 in), and an Ogyginus forteyi from Portugal was almost as long.

[666][667] The largest cyclid was Opolanka decorosa, the Late Triassic Halicyne-like cycloid which reached over 6 cm (2.4 in) across the carapace.