Largest organisms

For the prehistoric organisms, see Largest prehistoric organisms.

An aspen grove at Fishlake National Forest, similar in appearance to the one known as Pando.

The largest organisms found on Earth can be determined according to various aspects of organism size, such as: mass, volume, area, length, height, or even genome size.

The aspen tree (Populus tremuloides) forms large stands of genetically identical trees (technically, stems) connected by a single underground root system. These trees form through root sprouts coming off an original parent tree, though the root system may not remain a single unit in all specimens. The largest known fully connected aspen is a grove in Utah nicknamed Pando, and some experts call it the largest organism in the world, by mass or volume. It covers 0.43 km² (106 acres) and is estimated to weigh 6,600 short tons (6,000 t).

A giant Armillaria solidipes fungus, a species of honey mushroom in the Malheur National Forest in Oregon, was found to span 8.9 km² (2,200 acres), which would make it the largest organism by area. Whether or not this is an actual individual organism, however, is disputed: some tests have indicated that they have the same genetic makeup, but unless its mycelia are fully connected, it is a clonal colony of numerous smaller individuals. Another clonal colony that rivals the Armillaria and the Populus colonies in size is a strand of the giant marine plant, Posidonia oceanica, discovered in the Mediterranean near the Balearic Islands. It covers a band roughly 8 km (5.0 mi) in length.

The world's largest single stem tree, by volume, is the General Sherman tree, a Giant Sequoia with a volume of 1,487 m³ (52,500 cu ft). This tree stands 83.8 m (275 ft) tall and the trunk alone is estimated to weigh over 2,000 short tons (1,800 t). The largest single-stem tree ever measured was the Lindsey creek tree, a Coast Redwood with a minimum trunk volume of over 2,500 m³ (88,000 cu ft) and a mass of over 3,600 short tons (3,300 t). It fell over during a storm in 1905.

The largest known animal ever to have existed is the blue whale, an endangered species whose official record length is 33.58 m (110 ft 2 in), and weight 190 metric tons (210 short tons) (for a pregnant female). The largest living land animals by mass are male (bull) African Bush Elephants (Savannah Elephants or Bush Elephants); one known example weighed roughly 27,000 lb (12 t). Some extinct land animals, including many dinosaurs, were much larger still. A 1985 study concluded that the theoretical limit for land-dwelling animals based on known types of body plans was between 100 and 1000 metric tons. It should be noted that the organism sizes listed below are frequently considered "outsized" and are not in the normal (average) size range for the respective species.

Some organisms group together to form a superorganism, but such are not classed as single large organisms. The Great Barrier Reef is the world's largest structure composed of living entities, stretching 2,000 km, but contains many organisms of many species.

Animals

The Blue Whale is the heaviest animal ever known to have existed.

A member of the order Cetacea, the Blue Whale (Balaenoptera musculus) is believed to be the largest animal ever to have lived. Although distributed in all the world’s oceans, the heavily whaled specimens from the Antarctica seas are the largest-bodied. The maximum recorded weight was 190 metric tons (210 short tons) for a specimen measuring 30 m (98 ft), while longer ones, up to 33.4 m (110 ft), have been recorded but not weighed. The African Bush Elephant (Loxodonta africana), of the order Proboscidea, is the largest living land animal. A native of various open habitats in sub-Saharan Africa, this elephant is born commonly weighing about 100 kg (220 lb). The largest elephant ever recorded was shot in Angola in 1955. It was a male and weighed 12.2 metric tons (13.4 short tons), with an overall length (trunk to tail) of 10 m (33 ft) and a shoulder height of 4.12 m (13.5 ft).

Table of heaviest living animals

The following is a list of the heaviest animals, which are all cetaceans. These whales also qualify, of course, as the largest living mammals. Since no scale is large enough to accommodate the huge body of a large whale, most whales have been weighed piecemeal, with several individual parts of the body weighed and then added together to ascertain the total mass of the animal.

Rank	Animal	Average Mass	Maximum Mass	Average Total Length
1	Blue Whale	110,000 kg (240,000 lb)	190,000 kg (420,000 lb)	25.5 m (84 ft)
2	North Pacific Right Whale	60,000 kg (130,000 lb)	120,000 kg (260,000 lb)	15.5 m (51 ft)
3	Southern Right Whale	58,000 kg (128,000 lb)	110,000 kg (240,000 lb)	15.25 m (50.0 ft)
4	Fin Whale	57,000 kg (126,000 lb)	120,000 kg (260,000 lb)	20.6 m (68 ft)
5	North Atlantic Right Whale	55,000 kg (121,000 lb)	100,000 kg (220,000 lb)	15 m (49 ft)
6	Bowhead Whale	54,500 kg (120,200 lb)	120,000 kg (260,000 lb)	15 m (49 ft)
7	Sperm Whale	31,250 kg (68,890 lb)	57,000 kg (126,000 lb)	13.25 m (43.5 ft)
8	Humpback Whale	29,000 kg (64,000 lb)	48,000 kg (106,000 lb)	13.5 m (44 ft)
9	Sei Whale	22,500 kg (49,600 lb)	45,000 kg (99,000 lb)	14.8 m (49 ft)
10	Gray Whale	19,500 kg (43,000 lb)	45,000 kg (99,000 lb)	13.5 m (44 ft)

Table of heaviest terrestrial animals

The following is a list of the heaviest wild land animals, which are all mammals. The walrus is included because (unlike the larger elephant seals) it spends a great deal of time on land. The African elephant is now listed as two species, the African Bush Elephant and the African Forest Elephant, as they are generally considered to be two separate species now.

Rank	Animal	Average Mass	Maximum Mass	Average Total Length
1	African Bush Elephant	4,900 kg (10,800 lb)	12,274 kg (27,060 lb)	7.5 m (25 ft)
2	Asian Elephant	4,150 kg (9,150 lb)	8,000 kg (18,000 lb)	6.8 m (22 ft)
3	African Forest Elephant	2,800 kg (6,200 lb)	6,000 kg (13,000 lb)	6.2 m (20 ft)
4	White Rhinoceros	2,100 kg (4,600 lb)	4,500 kg (9,900 lb)	4.4 m (14 ft)
5	Indian Rhinoceros	1,900 kg (4,200 lb)	4,000 kg (8,800 lb)	4.2 m (14 ft)
6	Hippopotamus	1,800 kg (4,000 lb)	4,500 kg (9,900 lb)	4 m (13 ft)
7	Javan Rhinoceros	1,715 kg (3,781 lb)	2,300 kg (5,100 lb)	3.8 m (12 ft)
8	Black Rhinoceros	1,100 kg (2,400 lb)	2,896 kg (6,385 lb)	4 m (13 ft)
9	Giraffe	1,015 kg (2,238 lb)	1,930 kg (4,250 lb)	5.15 m (16.9 ft)
10	Walrus	944 kg (2,081 lb)	2,000 kg (4,400 lb)	2.8 m (9.2 ft)

Vertebrates

Mammals (Mammalia)

Main article: Largest mammals

• Tenrecs and allies (Afrosoricida)

The largest of these insectivorous, mammals is the Giant Otter Shrew (Potamogale velox), native to Central Africa.

The amphibious Hippopotamus is the most massive of the even-toed ungulates.

• Even-toed Ungulates (Artiodactyla)
  • The largest species in terms of weight is the Hippopotamus (Hippopotamus amphibius), native to the rivers of sub-Saharan Africa. This beast can reach a maximum size of 4,500 kg (10,000 lb), 4.8 m (16 ft) long and 1.66 m (5.5 ft) tall.
  • The longest-bodied species, and tallest of all living land animals, is the Giraffe (Giraffa camelopardalis), measuring up to 5.8 m (19.3 ft) tall to the top of the head, and despite being relatively slender, reaching a top weight of 2,000 kg (4,400 lb).
  • The largest extant respresentative of the bovids, a diverse and well-known family, is the Asian forest-dwelling Gaur (Bos gaurus), in which bulls can weigh up to 1,500 kg (3,300 lb), 4.5 m (15 ft) in total length and stand 2.2 m (7.2 ft) at the shoulder. The extinct Giant Bison (Bison latifrons) may be the largest bovid in the fossil record, with an estimated shoulder up to 2.5 m (8.2 ft) and a weight over 2,000 kg (4,400 lb). Domestic cattle (Bos primigenius taurus) are usually smaller, although obese steers have been reported to weigh up to 2,140 kg (4,720 lb).
  • The largest species in the pig family is generally the Giant Forest Hog (Hylochoerus meinertzhageni), a native of the African rainforests, at up to 275 kg (606 lb), 2.55 m (8.4 ft) in length and 1.1 m (3.6 ft) high at the shoulder. Although Wild Boars (Sus scrofa) have reportedly reached 320 kg (710 lb) historically and obese domestic pigs (S. s. domesticus) have been weighed to 1,157 kg (2,551 lb).
  • The largest living cervid is the moose (Alces alces), particularly the Alaskan subspecies, verified at up to 820 kg (1,810 lb), a total length of 3.5 m (11 ft) and a shoulder height of 2.4 m (7.9 ft). The extinct Irish Elk (Megaloceros giganteus) was of similar size to the Alaskan Moose but could have antlers spanning up to 4.3 metres (14 ft) across, about twice the maximum span for a Moose's antlers.
  • The largest members of the camel family are either the Bactrian (Camelus bactrianus), which is still wild in the steppe of central Asia, or the Dromedary Camels (Camelus dromedarius), which no longer exists in the wild but is widespread in the Middle East as a domestic animal, with a large introduced feral population in Australia. Both camels can weigh up to 1,000 kg (2,200 lb), 4 m (13 ft) in total length, 2.5 m (8.2 ft) tall at the shoulder and a height of 3.45 m (11.3 ft) at the hump. Several giant camels are known from fossils, perhaps the largest being Titanotylopus of North America, at up to 2,000 kg (4,400 lb) and a 3.4 m (11 ft) shoulder height.
  • An ancient relative of the even-toed ungulates, Andrewsarchus, may have been the largest carnivorous land mammal ever, despite almost all living species being herbivorous. Known only from a 0.83 m (2.7 ft) skull found in Mongolia, about twice the size of a brown bear skull, this great beast has been estimated to range as high in size as 2 m (6.6 ft) at the shoulder and 4.5 m (15 ft) in length. Weight estimates range anywhere from 454 to 1,816 kg (1,001 to 4,004 lb) based on the unknown proportion of the skull's size relative to the body size.

The enormous beachmaster Southern Elephant Seal is the largest of the carnivores.

• Carnivores (Carnivora)
  • The largest species is now, with the inclusion of the Pinnipedia, the Southern Elephant Seal (Mirounga leonina) from the Phocidae family, a monstrous dweller of the sub-Antarctic oceans in which "beachmaster" males dwarf their female mates. The top size recorded for this species was 5,000 kg (11,000 lb) and 6.9 m (22.5 ft) long. Other giant pinnipeds include the Northern Elephant Seal (M. angustirostris), at up to 3,700 kg (8,200 lb), and the Walrus (Odobenus rosmarus), at up to 2,000 kg (4,400 lb). The largest of the eared seal family is the Steller Sea Lion (Eumetopias jubatus) at up to 1,135 kg (2,502 lb) and 3.25 m (10.7 ft) long.
  • The largest living land carnivores are the Polar Bear (Ursus maritimus) and the coastal subspecies of the Brown Bear (Ursus arctos). Since they have similar body sizes, it is not clear which is definitively larger. In both species, shoulder height has been measured at more than 1.6 m (5.2 ft) and total length at as much as to 3.05 m (10.0 ft). The heaviest polar and brown bear weights recorded were respectively 1,003 kg (2,211 lb) and 1,135 kg (2,502 lb). However the largest bear, and one of the largest mammalian land carnivores of all time, was Arctotherium angustidens of the genus Arctotherium or the South American short-faced bears. A humerus of A. angustidens from Buenos Aires indicate that the big males of this species would have weighed 1,650 kg (3,640 lb) and stood at least 3.4 m (11 ft) tall on the hind-limbs.
  • The largest living member of the Felidae family (cats) is the tiger. The Siberian Tiger (Panthera tigris altaica) is the largest subspecies, averaging around 230 kg (500 lb) for males, but can reach around 270–310 kg (600–675 lb). Siberian Tigers up to 384 kg (845 lb) have been reported but are unconfirmed, while one Bengal Tiger (P. t. tigris) weighed a confirmed 389 kg (858 lb) after eating a buffalo the previous day. Tigers can reach up 3.5 m (11 ft) in total length and stand up to 1.21 m (4.0 ft) at the shoulder. Even larger were the extinct American Lion (Panthera leo atrox) and the saber-toothed Smilodon populator of eastern South America, both estimated to have weighed up to 453 kg (999 lb). Captive ligers (hybrids between lions and tigers) can grow huge and obese, at up to 726 kg (1,601 lb), far exceeding natural weights.
  • The largest known extant member of Canidae is the gray wolf (Canis lupus). The largest specimens from the Mackenzie Valley Wolf (C. l. occidentalis) or the Eurasian Wolf (C. l. lupus) weigh up to 80–86 kg (176–190 lb) and measure up to 2.5 m (8.2 ft) in total length and 0.9 m (3.0 ft) tall at the shoulder. Domestic dogs can occasionally grow heavier, up to 155.6 kg (343 lb). The largest known canid is an extinct member of subfamilly Borophaginae, in the genus Epicyon: Epicyon haydeni. The largest known specimen of this species weighed an estimated 170 kg (370 lb).
  • The largest and most diverse family of carnivores, the mustelids, reaches their maximum size (by mass) in the sea otter (Enhydra lutris) of the North Pacific coasts, at up to 54 kg (119 lb), and (by length) the giant otter (Pteronura brasiliensis) of the Amazonian rainforests, at up to 2.4 m (7.9 ft) in total.
  • The largest species in the Herpestidae (mongoose) family is the African White-tailed Mongoose (Ichneumia albicauda), at up to 6 kg (13 lb) and 1.18 m (3.9 ft) long.
  • The largest species in the viverrid family is the Asian binturong (Arctictis binturong), at up to 27 kg (60 lb) and 1.85 m (6.1 ft) long, about half of which is tail.
  • The largest modern species in the Hyaenidae (hyena) family is the Spotted Hyena (Crocuta crocuta) of sub-Saharan Africa, at up to a maximum weight of 86–90 kg (190–198 lb). Spotted hyenas can range up to 2.13 m (7.0 ft) in total length and 93 cm (37 in) tall at the shoulder. The largest fossil hyena is the lion-sized Pachycrocuta, estimated at 200 kg (440 lb).

The orca is the largest oceanic dolphin.

• Whales (Cetacea)

The largest whale and animal is the previously-mentioned blue whale, a baleen whale (Mysticeti). Its closest competitors are also baleen whales, the Fin Whale (Balaenoptera physalus), which can reach a maximum size of 27 m (89 ft) in length and weight of 109 metric tons (120 short tons), and the Bowhead (Balaena mysticetus) and North Pacific Right Whale (Eubalaena japonica), both measured up to 21.2 m (70 ft) and estimated at that length to weigh about 133 metric tons (147 short tons). The largest toothed whale (Odontoceti) is the Sperm Whale (Physeter macrocephalus), bulls of which usually range up to 18.2 m (60 ft) long and a mass of 50 metric tons (55 short tons). Whaling records and skeletal remains have indicated that, in the past, sperm whales could have grown to 26 metres (85 ft) long. The Orca or Killer Whale (Orcinus orca) is the largest species of the oceanic dolphin family. The largest Orca ever recorded was a male off the coast of Japan, measuring 9.7 m (32 ft) long and weighed 10 metric tons (11 short tons). The largest porpoise is the Dall's Porpoise (Phocoenoides dalli), at up to 220 kg (490 lb) and 2.2 m (7.2 ft) in length; while the largest beaked whale is the Baird's Beaked Whale (Berardius bairdii) at up to 14 metric tons (15 short tons) and 13 m (43 ft) long.

The largest bat, the Giant golden-crowned flying fox is about as large as a hare.

• Bats (Chiroptera)

The largest bat species is the Giant golden-crowned flying fox (Acerodon jubatus), an endangered fruit bat from the rainforests of the Philippines that is part of the megabat family. The maximum size is believed to approach 1.5 kg (3.3 lb), 55 cm (22 in) long, and the wingspan may be almost 1.8 m (5.9 ft). The Large Flying Fox (Pteropus vampyrus) is smaller in body mass and length, but it has been known to exceed the Golden-crowned species in wingspan. Specimens have been verified to 1.83 m (6.0 ft) and possibly up to 2 m (6.6 ft) in wingspan. The neotropical Spectral Bat (Vampyrum spectrum), at up to 95 g (3.4 oz), 14 cm (5.5 in) long and about 0.9 m (3.0 ft) in wingspan, is believed to be the largest carnivorous bat, belonging to the microbat family.

• Armadillos (Cingulata)

The extant giant of this group is the Giant Armadillo (Priodontes maximus), native to tropical South America. The top size for this species is 54 kg (119 lb), 0.55 m (1.8 ft) high at the shoulder and 1.6 m (5.2 ft) in length, although captive specimens can weigh up to 80 kg (180 lb). Much larger prehistoric examples are known, especially Glyptodon of the Americas, which easily topped 2 tonnes (4,400 lb) and could reach 4 m (13 ft) in total length and 1.53 m (5.0 ft) high at the shoulder.

• Colugos (Dermoptera)

Of the two colugo species in the order Dermoptera of gliding arboreal mammals in southeast Asia, the largest and most common is the Sunda Flying Lemur (Cynocephalus varigatus). The maximum size is 2 kg (4.4 lb) and 73 cm (29 in) in length.

• Hedgehogs & gymnures (Erinaceomorpha)

The largest of this order and family of prickly-skinned, small mammals is the Greater Moonrat (Echinosorex gymnura), native to the rainforests of the Malaysian Peninsula as well as Sumatra and Borneo. The maximum size of this species is over 2 kg (4.4 lb) and 60 cm (24 in). The moonrat is a member of the same family as hedgehogs, which are typically much smaller than the Moonrat.

• Hyraxes (Hyracoidea)

The largest species of hyrax seems to be the Cape Hyrax (Procavia capensis), at up to 5.4 kg (12 lb) and 73 cm (29 in) long. Prehistorically, the hyraxes were, for a time, the primary terrestrial herbivores in Africa, and some forms grew as large as horses.

The European Hare is one of the largest living lagomorphs

• Rabbits, hares, and pikas (Lagomorpha)

The largest extant wild species may be the European Hare (Lepus europaeus), native to western and central Eurasia. This lagomorph can range up to 7 kg (15 lb) in weight and 0.85 m (2.8 ft) in total length. However, the Alaskan Hare (Lepus othus) has almost the same exact body-proportions and weighs slightly more, averaging 4.8 kg (11 lb) and reaching a maximum mass of 7.2 kg (16 lb). Also, an occasional Arctic Hare (L. arcticus) can also weigh as much as 7 kg (15 lb) but is typically smaller overall than the European and Alaskan species. The largest domestic rabbit breed is the Flemish Giant, which can weigh up to 12.7 kg (28 lb). The largest lagomorph ever was Nuralagus rex, native to Minorca, which could have possibly grown up to 23 kg (51 lb).

• Elephant Shrews (Macroscelidea)

The elephant shrews are named for their shrew-like snouts, but these animals are in fact not closely related to true shrews and are a unique group behaviorly and in appearance. The largest variety is the recently discovered Grey-faced Sengi (Rhynchocyon udzungwensis), known only from the Udzungwa Mountains of Tanzania and Kenya. This elephant shrew can range up to 0.75 kg (1.7 lb) and a length of 0.6 m (2.0 ft).

• Marsupials (Marsupialia)

The Red Kangaroo (Macropus rufus) of Australia is the largest living marsupial. These lanky mammals has been verified to 91 kg (200 lb) and 2.18 m (7.1 ft) when standing completely upright. Unconfirmed specimens have been reported up to 150 kg (330 lb). Many much larger marsupials existed prehistorically, the largest of which was Diprotodon. This rhino-sized herbivore would have reached more than 3.3 m (11 ft) in length and stood 1.83 m (6 ft) at shoulder and was estimated to weigh up to 3,000 kg (6,600 lb). The Tasmanian Devil (Sarcophilus harrisii), endemic to Tasmania, is the largest living carnivorous marsupial. These stocky mammals can range up to 14 kg (31 lb) and 1.1 m (3.6 ft) in total length. The largest ever carnivorous marsupial to exist would have been the Australian Marsupial Lion (Thylacoleo) and the South American Saber-toothed Marsupial (Thylacosmilus) both ranging from 1.53 m (5.0 ft) to 1.83 m (6.0 ft) long and weighing between 100 kg to 160 kg (220-352 lbs).

• Monotreme mammals (Monotremata)

The largest extant monotreme (egg-bearing mammal) is the Western Long-beaked Echidna (Zaglossus bruijni) weighing up to 16.5 kg (36.4 lb) and measuring 1 m (3.3 ft) long. The largest monotreme ever was the extinct echidna species Zaglossus hacketti, known only from a few bones found in Western Australia. It was the size of a sheep, weighing probably up to 100 kg (220 lb).

The largest odd-toed ungulates, White Rhinoceros

• Odd-toed Ungulates (Perissodactyla)

The largest extant species is the White Rhinoceros (Ceratotherium simum). The largest size this species can attain is 4,500 kg (10,000 lb), 4.7 m (15 ft) in total length, and 2 m (6.6 ft) tall at the shoulder. It is slightly larger than the Indian Rhinoceros (Rhinoceros unicornis), which can range up to a weight of 4,000 kg (8,800 lb). The largest extant wild equids are the Grevy's zebra, at up to 450 kg (990 lb), a shoulder height of 1.6 m (5.2 ft) and total length of 3.8 m (12 ft). Until it was domesticated into extinction the wild horse (Equus ferus ferus) was the largest equid. Domestic horses can reach a maximum weight of 1,524 kg (3,360 lb) and shoulder height of 2.2 m (7.2 ft). The largest land mammal ever was Paraceratherium or Indricotherium (formerly known as the Baluchitherium), a member of this order. The largest known species (Paraceratherium orgosensis) is believed to have stood up to 5.5 m (18 ft) tall, measured over 9 m (30 ft) long and may have weighed up to 20 metric tons (22 short tons).

• Pangolins (Pholidota)

The largest species of scaly anteater is the Giant Pangolin (Manis gigantea), at up to 1.7 m (5.8 ft) and at least 40 kg (88 lb).

The Giant Anteater is one of the largest neotropical mammals

• Anteaters and sloths (Pilosa)

The largest species is easily the Giant Anteater (Myrmecophaga tridactyla). A large adult can weigh as much as 65 kg (143 lb), be over 0.6 m (2.0 ft) tall at the shoulder and measure 2.4 m (8 ft) in overall length. The largest living sloths are the Linnaeus's (Choloepus didactylus) and Hoffmann's Two-toed Sloths (C. hoffmanni), which both can range up to 10 kg (22 lb) and 0.86 m (2.8 ft) long. The sloths attained much larger sizes prehistorically, the largest of which were Megatherium which, at an estimated average weight of 4.5 tonnes (5 short tons) and height of 5.1 m (17 ft), was about the same size as the African Bush Elephant.

The Eastern Lowland Gorilla is the largest living primate.

• Primates (Primates)

The Gorillas are the largest living primates, with the Eastern Lowland Gorilla (Gorilla beringei graueri) race averaging the largest. The largest wild male gorillas were 266 kilograms (586 lb) and 1.94 metres (6.4 ft) tall, respectively, although heavier weights have been recorded in captivity. Gigantopithecus is the largest known primate ever, probably averaged 3 m (10 ft) tall and weighing 300 to 550 kg (700 to 1,200 lb). It lived from around five million years ago to about 300,000 years ago in the region of India and China. The largest of the Old World Monkeys is the Mandrill (Mandrillus sphinx), at up to 50 kg (110 lb) and 1 m (3.3 ft) long in large males. The largest New World Monkey is the Southern Muriqui (Brachyteles arachnoides), at up to 15 kg (33 lb) and 1.6 m (5.2 ft) in total length (which includes an extremely long tail). The Indri (Indri indri), the largest lemur, can weigh up to 12 kg (26 lb) and measure 1.45 m (4.8 ft) in total length, although giant prehistoric forms are known, the largest being Archaeoindris, at 200 kg (440 lb).

Humans (Homo sapiens) can attain massive weights (largest ever documented human, Jon Brower Minnoch, was 636 kg (1,402 lb). However, these are cases of morbid obesity, tumor, and other medical malady. Similarly, humans can attain enormous heights (tallest documented was 8 ft 11 inches (272 cm), Robert Wadlow) due to gigantism. Even when not afflicted with gigantism, humans are the tallest living primates.

The African Bush Elephant, the largest living terrestrial animal.

• Elephants, mammoths, and mastodons (Proboscidea)

Most extinct species in the order Proboscidea, such as mammoths and mastodons, did not dwarf the modern African Bush Elephant but some could grow somewhat larger. Deinotherium, which may have surpassed 14 tonnes (15 short tons), is perhaps the most massive species. Various mammoths surpassed the modern elephant (which rarely exceeds 7 tonnes) in size, including the North American Imperial Mammoth (Mammuthus imperator), Northern Chinese Songhua River Mammoth (M. sungari) and the Northern Eurasian Steppe Mammoth (M. armeniacus). Each of these mammoths could exceed a shoulder height of 5 m (16 ft) tall and could approach or exceed the weight of Deinotherium.

The Capybara is the largest living rodent.

• Rodents (Rodentia)

The largest living rodent is the capybara (Hydrochoerus hydrochaeris), native to most of the tropical and temperate parts of South America east of the Andes, always near water. Full-grown capybaras can reach 1.5 m (4.9 ft) long and 0.9 m (3.0 ft) tall at the shoulder and a maximum weight of 105.4 kg (232 lb). The second largest living rodent is the American Beaver (Castor canadensis), which favors water perhaps even more than its larger cousin. Outsized male beaver specimens have been recorded up to 50 kg (110 lb), which is about twice the normal weight for a beaver, and 1.7 m (5.6 ft) in total length. The largest species in the squirrel family is the Hoary Marmot (Marmota caligata) of the Pacific Northwest, at up to 13.5 kg (30 lb) and 0.8 m (2.6 ft) long. The largest rat or mouse is believed to be the recently discovered Bosavi Woolly Rat (Mallomys) of Papua New Guinea, at 0.82 m (2.7 ft) and 1.5 kg (3.3 lb). However, a better-known member of the rat superfamily, the aquatic North American Muskrat (Ondatra zibethicus), can weigh up to 1.8 kg (4.0 lb). The largest known rodent ever is Josephoartigasia monesi, an extinct species known only from fossils found in Uruguay. It was approximately 3 metres (10 ft) long and 1.5 metres (5 ft) tall, and is estimated to have weighed 1.5–2.5 metric tons (1.7–2.8 short tons). Prior to the description of J. monesi, the largest known rodent species were from the genus Phoberomys, of which two species have been discovered. An almost complete skeleton of the slightly smaller Late Miocene species, Phoberomys pattersoni, was discovered in Venezuela in 2000; it was approximately 3 m (10 ft) long, with an additional 1.5 m (5 ft) tail, and probably weighed around 700 kg (1,540 lb).

• Tree Shrews (Scandentia)

The largest of the tree shrews seems to be the Common Tree Shrew (Tupaia glis), at up to 187 g (6.6 oz) and 40 cm (17 in).

A good-sized West Indian Manatee, the largest living sirenian, can weigh well over a ton.

• Dugongs and manatees (Sirenia)

The largest living species in the order Sirenia of dugongs and manatees is the West Indian Manatee (Trichechus manatus). The largest manatees are found in the Florida subspecies.Maximum recorded size of this species is 1,590 kg (3,500 lb) and 4.1 m (13.5 ft). However, the extinct Steller's Sea Cow (Hydrodamalis gigas) of the North Pacific was much larger, growing up to at least 7.9 m (26 ft) long and weighing up to 11 tonnes (12.1 short tons).

• Shrews and moles (Soricomorpha)

The largest species of shrew, among the smallest types of mammals, is the Asian House Shrew (Suncus murinus) of South Asia, weighing up to 100 g (3.5 oz) and length up to 16 cm (6.3 in). The largest mole is the amphibious Russian Desman (Desmana moschata), with a total length of up to 43 cm (1.41 ft) and an upper weight of 520 g (18 oz).

• Aardvark (Tubulidentata)

The only species in this order is the unique Aardvark (Orycteropus afer) of sub-Saharan Africa. Aardvarks are typically up to 1.3 m (4.3 ft) in length with an average weight of up to 65 kg (143 lb) and a shoulder height up to 0.65 m (2.1 ft). However, individuals as large as 2.2 m (7.2 ft) and as heavy as 100 kg (220 lb) are recorded.

Mammal-like reptiles (Synapsida)

A comparison of a human to the massive Cotylorhynchus, the largest of the early mammal-like reptiles.

The Permian era Cotylorhynchus, from what is now the southern United States, probably was the largest of all synapsids (which went extinct several hundred million years ago), at 20 feet (6 meters) and 2 tons. The largest carnivorous synapsid was Anteosaurus from what is now South Africa during Middle Permian era. Anteosaurus was 5 to 6 m (16–20 ft) long, and weighed about 500–600 kg (1,100–1,300 lb).

• Pelycosauria

The largest pelycosaur was the pre-mentioned Cotylorhynchus, and the largest predatory pelycosaurus was Ivantosaurus from what is now Russia, with a length of 20 feet (6 meters).

• Therapsida

Moschops was the largest therapsid, with a weight of 700 to 1,000 kg (1,500 to 2,200 lb), and a length of about 5 m (16 ft). The largest carnivorous therapsid was the aforementioned Anteosaurus.

Reptiles (Reptilia)

Main article: Largest reptiles

The saltwater crocodile is the largest living reptile.

The largest living reptile, a representative of the order Crocodilia, is the saltwater crocodile (Crocodylus porosus) of Southern Asia and Australia, with adult males being typically 3.9 to 5.5 m (13–18 ft) long. The largest confirmed saltwater crocodile on record was 6.3 m (20 ft 8 in) long, and weighed over 1,360 kg (3,000 lbs). Unconfirmed reports of much larger crocodiles exist, but examinations of incomplete remains have never suggested a length greater than 7 m (23 ft). Also, a living specimen estimated at 7 m (23 ft) and 2,000 kg (4,400 lb) has been accepted by the Guinness Book of World Records. Some other large modern crocodilians can also be very large although none regularly exceed 4.9 m (16 ft) in length other than the saltwater croc. Other large species include the slender-snouted gharial (Gavialis gangeticus), which has been measured up to 7 m (23 ft), the american (Crocodylus acutus) & the orinoco crocodile (C. intermedius) both reported, but not verified, to 6.7 m (22 ft) and the nile crocodile, verified up to 6.45 m (21.2 ft) and a weight of 1,089 kg (2,401 lb). The largest living specimen of a nile crocodile is purported to be a man-eater from Burundi named Gustave; he is believed to be more than 20 ft (6.1 m) long. Members of the Alligatoridae don't usually grow as large as the preceding crocodilians, but unverified reports suggest lengths of up to 6.09 m (20.0 ft) for the black caiman (Melanosuchus niger) and 5.8 m (19 ft) for the american alligator (Alligator mississippiensis).

However, extinct crocodilians were sometimes much larger, such as the late Cretaceous era Deinosuchus of what is now North America, at up to 12 m (40 ft) and 9 tonnes (10 tons). Sarcosuchus imperator of the early Cretaceous was found in the Sahara desert and could also measure up to 12 m (40 ft) and weigh an estimated 13.6 tonnes (15 tons). The caiman-related Purussaurus, from northern South America during the Miocene era which was 12 m (40 ft) as well. Possibly even longer than the previous species, Rhamphosuchus, which may have existed along side Purussaurus, could attain a length up to possibly 18 m (60 ft) long, but (based on its fossils) was less massive and heavy than the other mentioned crocodilians.

Table of heaviest living reptiles

The following is a list of the heaviest living reptile species, which is dominated by the crocodilians. Unlike the upper weights of mammals, birds or fish, mass in reptiles is frequently poorly documented and many are subject to conjecture and estimation.

Rank	Animal	Average Mass	Maximum Mass	Average Total Length
1	Saltwater Crocodile	454 kg (1,001 lb)	2,000 kg (4,400 lb)	3.85 m (12.6 ft)
2	Nile Crocodile	382 kg (842 lb)	1,089 kg (2,401 lb)	3.7 m (12 ft)
3	Leatherback sea turtle	364 kg (802 lb)	932 kg (2,055 lb)	2 m (6.6 ft)
4	Black Caiman	300 kg (660 lb)	1,310 kg (2,890 lb)	3.6 m (12 ft)
5	Orinoco Crocodile	290 kg (640 lb)	900 kg (2,000 lb)	3.6 m (12 ft)
6	American Crocodile	277 kg (611 lb)	1,000 kg (2,200 lb)	3.5 m (11 ft)
7	American Alligator	260 kg (570 lb)	1,000 kg (2,200 lb)	3.1 m (10 ft)
8	Aldabra Giant Tortoise	205 kg (452 lb)	360 kg (790 lb)	1.4 m (4.6 ft)
9	Gharial	200 kg (440 lb)	977 kg (2,154 lb)	3.8 m (12 ft)
10	Galapagos tortoise	175 kg (386 lb)	400 kg (880 lb)	1.5 m (4.9 ft)

• Lizards and snakes (Squamata)

The most massive living member of this giant reptilian order is the Green Anaconda (Eunectes murinus) of the neotropical riverways. The maximum verified size is 7.5 m (25 ft) and 250 kg (550 lb), although rumors of larger anacondas persist. The Reticulated Python (Python reticulatus) of Southeast Asia is longer but more slender, and has been reported to measure as much as 9.7 m (32 ft) in length. Among the colubrids, the most diverse snake family, the longest specimens are reported in Chinese Ratsnake (Ptyas korros), at up to 4.75 m (15.6 ft). The longest venomous snake is the South Asian King Cobra (Ophiophagus hannah), with lengths (recorded in captivity) of up to 5.7 m (19 ft) and a weight of up to 12.7 kg (28 lb). The heaviest venomous snake species is the North American Eastern Diamondback Rattlesnake (Crotalus adamanteus), the heaviest on record weighed 15.3 kg (34 lb) at 2.4 m (7.9 ft) in length. While the rattlesnake is the heaviest, another member of the viper family is longer, the South American Bushmaster (Lachesis muta), with a maximum length of 3.65 m (12.0 ft). The largest of the living lizards is the Komodo Dragon (Varanus komodoensis), endemic to the island of its name, at a maximum size of 3.13 m (10 ft 3 in) long and 166 kg (366 lb). By far the largest-ever members of this order were the giant mosasaurs (including Hainosaurus, Mosasaurus, and Tylosaurus), which grew to around 15 m (50 ft) and were projected to weigh up to 20 metric tons (22 short tons). The fossil of the largest snake ever, Titanoboa were found in coalmines in Colombia. This huge snake was estimated to have reached a maximum length of 12 to 15 m (40 to 50 ft), weighed about 1,135 kg (2,502 lb), and measured about 1 m (3 ft) in diameter at the thickest part of the body. The prehistoric Australian Megalania prisca (or Varanus priscus), which may have existed up to 40,000 years ago, is the largest terrestrial squamate known, but the lack of a complete skeleton has resulted in a wide range of size estimates. Molnar's 2004 assessment resulted in an average weight of 320 kg (710 lb) and length of 4.5 m (15 ft), and a maximum of 1,940 kg (4,280 lb) at 7 m (23 ft) in length, which is toward the high end of the early estimates.

The green anaconda is the most massive living snake.

• Plesiosaurs (Plesiosauria); now extinct

The largest known plesiosaur was Mauisaurus haasti, from the late Cretaceous oceans around what is now New Zealand. It is estimated to have grew to around 20 m (66 ft) in length.

• Ichthyosaurs (Ichthyosauria); now extinct

The largest of these marine reptiles (extinct for 90 million years) was the species Shastasaurus sikanniensis, at approximately 21 m (69 ft) long. This massive animal, from the Norian era in what is now British Columbia, is considered the largest marine reptile so far found in the fossil record.

• Tuataras (Sphenodontia)

The larger of the two extant species of the New Zealand native tuataras is the Brothers Island Tuatara (Sphenodon guntheri). The maximum size is 1.4 kg (3.1 lb) and 76 cm (30 in).

The giant Leatherback Sea Turtle, the largest extant turtle, digs a nest on the beach.

• Turtles (Testudines)

The largest living turtle is the Leatherback Sea Turtle (Dermochelys coriacea), reaching a maximum total length of 3 m (9.8 ft) and a weight of 932 kg (2,055 lb). There are many extinct turtles that vie for the title of the largest ever. The largest seems to be Archelon ischyros, also a sea turtle, which reached a length of 4.84 m (16 ft) across the flippers and a weight of over 2,200 kg (4,850 lb). The largest freshwater turtle is possibly the North American alligator snapping turtle (Macrochelys temminckii), which has an unverified maximum reported weight of 183 kg (403 lb), although this is challenged by several rare, giant softshell turtle from Asia (Rafetus and Pelochelys) unverified to 200 kg (440 lb) and nearly 2 m (6.6 ft) in total length. The Galápagos tortoise (Chelonoidis nigra) and the Aldabra Giant Tortoise (Aldabrachelys gigantea) are considered the largest truly terrestrial reptiles alive today. While the Aldabra tortoise averages larger at 205 kg (452 lb), the more variable-sized Galapagos tortoise can reach a greater maximum size of 400 kg (880 lb) and 1.85 m (6.1 ft) in total length. A much larger tortoise survived until about 2000 years ago, the Australasian Meiolania at about 2.6 m (8.5 ft) long and a weight of over a 1 metric ton (1.1 short tons). The tortoise Colossochelys atlas, of the Pleistocene era from what is now Pakistan and India, was even larger, at nearly 3.05 m (10.0 ft).

Comparison of a human to the largest flying animals known to have existed, Quetzalcoatlus.

• Pterosaurs (Pterosauria); now extinct

A dinosaur-era reptile (although not actually a dinosaur) is believed to have been the largest flying animal that ever existed: the pterosaur Quetzalcoatlus northropi, from North America during the late Cretaceous. This species is believed to have weighed up to 250 kg (550 lb) and measured up to 11 m (36 ft) across the wings. Another possible contender for the largest pterosaur is Hatzegopteryx, which is also estimated to have had an 11 metres (36 ft) wingspan.

• Dinosaurs (Dinosauria)

Main article: Dinosaur size

Scale diagram comparing a human and the largest known dinosaurs of the five major clades.

Size comparison of selected giant sauropod dinosaurs. Sauroposeidon (blue), Argentinosaurus (violet), and Amphicoelias fragillimus (red) size estimates are based on fragmentary fossil evidence.

Now extinct, except for theropod descendants, the Aves.

• Sauropods (Sauropoda)

Of all the largest dinosaurs, and the largest animals to ever live on land, were the plant-eating Sauropoda. The tallest and heaviest sauropod known from a complete skeleton is the Jurassic era Giraffatitan which was discovered in Tanzania between 1907 and 1912, and is now mounted in the Humboldt Museum of Berlin. It is 12 m (38 ft) tall, and probably weighed between 30,000–60,000 kg (30–65 short tons). The longest is the 25 m (82 ft) long, late Jurassic Diplodocus which was discovered in Wyoming, and mounted in Pittsburgh's Carnegie Natural History Museum in 1907.

There were larger sauropods, but they are known from only a few bones. The current record-holders had all been discovered before 1971, and include the massive Argentinosaurus, from the mid-Cretaceous, which may have weighed 80,000–100,000 kg (90 to 110 short tons); the longest, the 35 m (112 ft) long Jurassic era Supersaurus, which was discovered in Colorado; and the tallest, the 18 m (60 ft) tall Sauroposeidon, from the Early Cretaceous in what is now Oklahoma, which could have reached into a 6th-floor window. Diplodocus hallorum (formerly known as Seismosaurus) was once thought to have been about 50 m (170 ft) long, making it the longest known vertebrate, but later reconstructions estimate the length at 35 m (115 ft).

Less well described finds may exceed this. Bruhathkayosaurus (discovered in the southern tip of India) may have approached the weight of a Blue Whale, and Amphicoelias fragillimus from Colorado would have been longer still, at an estimated 60 m (200 ft), but considerably lighter. However, Bruhathkayosaurus is based on very poor material, and the only fossil of Amphicoelias was lost.

Size comparison of selected giant theropod dinosaurs

• Theropods (Theropoda)

The longest and heaviest theropod is believed to be the Spinosaurus of the mid-Cretaceous, at 16 to 18 metres (52 to 59 ft) long and 7 to 9 tonnes (7.7 to 9.9 short tons) in weight. This is significantly more massive than other contenders such as the Giganotosaurus and Tyrannosaurus. Spinosaurus is notable for having been the largest terrestrial predator known to exist.

The longest and heaviest theropod known from a complete skeleton is the Tyrannosaurus specimen nicknamed "Sue", which was discovered in South Dakota in 1990 and is now mounted in the Field Museum of Chicago. This late Cretaceous giant is 12.2 m (40 ft) long, and probably weighed 6.8 metric tons (7.5 short tons).

The largest dromaeosaurid is Utahraptor of the early Cretaceous. In addition to being the largest known dromaeosaurid, it was also the largest known deinonychosaur and the largest known paravian. Larger complete specimens of this species are up to 7 m (23 ft) long and are estimated to have weighed about 600 kg (1,300 lb).

• Armored Dinosaurs (Thyreophora)

The longest of the thyreophorans were Ankylosaurus and Stegosaurus, from the Late Cretaceous and Late Jurassic periods (respectively) in what is now Western North America, and both of which measured up to 9 metres (30 ft) in length.

• Cerapods (Cerapoda)

The largest cerapods were the hadrosaurids Shantungosaurus, a late Cretaceous dinosaur found in the Shandong Peninsula of China, and "Lambeosaurus" laticaudus, from the late Cretaceous North America. Both species are known from fragmentary remains but are estimated to have reached over 15 m (50 ft) in length and weighed over 23 tonnes (50,700 lb).

• Ornithopods (Ornithopoda)

The very largest ornithopods, like the Late Cretaceous Shantungosaurus were as heavy as medium sized sauropods at up to 23 metric tons (25 short tons) but never grew far beyond 15 meters (50 feet).

• Ceratopsians (Ceratopsia)

The largest ceratopsian was Triceratops, a late Cretaceous dinosaur found in fossil throughout North America. Triceratops is estimated to have reached about 8 m (26 ft) in length and weighed 12 tonnes (26,900 lb). Recently discovered in Canada, Eotriceratops had a skull estimated to be longer than 3 m (9.8 ft), and may have been larger than Triceratops.

Birds (Aves)

Main article: Largest birds

The Ostrich is the largest living bird.

The largest living bird, a member of the Struthioniformes, is the ostrich (Struthio camelus), from the plains of Africa and Arabia. A large male Ostrich can reach a height of 2.8 m (9.2 ft) and weighing over 156 kg (345 lb). A mass of 200 kg (440 lb) has been cited for the ostrich but no wild ostriches of this massive weight have been verified. Eggs laid by the Ostrich can weigh 1.4 kg (3 lb) and are the largest eggs in the world today.

The largest bird in the fossil record may be the extinct elephant birds (Aepyornis) of Madagascar, which were related to the ostrich. They exceeded 3 m (10 ft) in height and 500 kg (1,120 lb). The last of the elephant birds became extinct about 300 years ago. Of almost exactly the same upper proportions as the largest elephant birds was Dromornis stirtoni of Australia, part of a 26,000-year-old group called mihirungs of the family Dromornithidae. The largest carnivorous bird was Brontornis, an extinct flightless bird from South America which reached a weight of 350 to 400 kg (770 to 880 lb) and a height of about 2.8 m (9 ft 2 in). The tallest bird ever however was the Giant Moa (Dinornis maximus), part of the moa family of New Zealand that went extinct about 200 years ago. This moa stood up to 3.7 m (12 ft) tall, but weighed about half as much as a large elephant bird or mihirung due to its comparatively slender frame.

The largest bird ever capable of flight was Argentavis magnificens, a now extinct member of the Teratornithidae group found in Argentine fossil beds, with a wingspan up to 8.3 m (28 ft), a length of up to 3.5 m (11 ft), a height on the ground of up to 2 m (6.6 ft) and a body weight of at least 80 kg (180 lb).

Table of heaviest living birds

The following is a list of the heaviest living bird species. These species are almost all flightless, which allows for these particular birds to have denser bones and heavier bodies. Flightless birds comprise less than 2% of all living bird species. One flying species, the corpulent Dalmatian pelican, ranks on the list.

Rank	Animal	Average Mass	Maximum Mass	Average Total Length
1	Ostrich	104 kg (229 lb)	156.8 kg (346 lb)	210 cm (6.9 ft)
2	Southern Cassowary	45 kg (99 lb)	85 kg (187 lb)	155 cm (5.09 ft)
3	Northern Cassowary	44 kg (97 lb)	75 kg (165 lb)	149 cm (4.89 ft)
4	Emu	33 kg (73 lb)	70 kg (150 lb)	153 cm (5.02 ft)
5	Emperor Penguin	31.5 kg (69 lb)	46 kg (101 lb)	114 cm (3.74 ft)
6	Greater Rhea	23 kg (51 lb)	40 kg (88 lb)	134 cm (4.40 ft)
7	Dwarf Cassowary	19.7 kg (43 lb)	34 kg (75 lb)	105 cm (3.44 ft)
8	Lesser Rhea	19.6 kg (43 lb)	28.6 kg (63 lb)	96 cm (3.15 ft)
9	King Penguin	13.6 kg (30 lb)	20 kg (44 lb)	92 cm (3.02 ft)
10	Dalmatian Pelican	11.5 kg (25 lb)	15 kg (33 lb)	170 cm (5.6 ft)

The Eurasian Black Vulture is the biggest of the living birds of prey

• Birds of prey (Accipitriformes)

The largest extant species is the Eurasian Black Vulture (Aegypius monachus), attaining a maximum size of 14 kg (31 lb), 1.2 m (3.9 ft) long and 3.1 m (10 ft) across the wings. Other vultures can be nearly as large, with the huge Himalayan Vulture (Gyps himalayensis) reaching lengths up to 1.5 m (4.9 ft) thanks in part to its long neck. The largest living eagle (the larger varieties of active-hunting raptors) is a source of contention, with the Philippine Eagle (Pithecophaga jefferyi), at up to 1.12 m (3.7 ft), being the longest. The Steller's Sea Eagle (Haliaeetus pelagicus) of Asia's North Pacific, at unconfirmed weights of up to 12.7 kg (28 lb) and an average weight of 6.7 kg (15 lb), is regarded as the heaviest eagle. The Harpy Eagle (Harpia harpyja) of the neotropical forests is the often cited as the largest eagle, as well, and captive females have weighed up to 12.3 kg (27 lb). The longest-winged eagle ever was a Australian Wedge-tailed Eagle (Aquila audax) at 2.83 m (9.3 ft), though this species is not as large as the previous species. The Golden Eagle (Aquila chrysaetos) is barely smaller winged, with the Himalayan subspecies recorded to 2.77 m (9.1 ft). The Harpy and Philippine Eagles, due to having to navigate in deep forest, are relatively short-winged, and do not exceed 2 m (6.6 ft) or 2.2 m (7.2 ft), respectively, in wingspan. The now extinct Haast's Eagle (Harpagornis moorei), which existed alongside early aboriginal people in New Zealand, was easily the largest eagle known and perhaps the largest raptor ever. Adult female Haast's were estimated to average up to 1.4 m (4.6 ft) long, a 15 kg (33 lb) body weight and a relatively short 3 m (9.8 ft) wingspan.

Migrating Trumpeter Swans, which are the largest waterfowl on earth.

• Waterfowl (Anseriformes)

The largest species in general is the Trumpeter Swan (Cygnus buccinator) of Northern North America, which can reach an overall length of 1.82 m (6 ft), a wingspan of 3 m (10 ft) and a weight of 17.3 kg (38 lb). However, as is commonly the case in more widespread and physically variable birds occasionally outsizing their larger-on-average cousins, the heaviest waterfowl ever recorded was a cob Mute Swan (Cygnus olor) from Poland, which weighed 23 kg (50 lb) and was allegedly too heavy to take flight. The members of the previously mentioned Dromornithidae are now classified as members of this order, making them the largest "waterfowl" that ever lived. The Eocene-era European Dasornis, which is generally classified as being in the order and would classify as the largest flying bird in it, had a wingspan of at least 4.9 m (16 ft) and possibly as much as 6.06 m (19.9 ft).

• Swifts and allies (Apodiformes)

The largest species are the White-naped Swift (Streptoprocne semicollaris), endemic to southern Mexico, and the Purple Needletail (Hirundapus celebensis), of the Philippine islands. Both reach similar large sizes, at up to 225 g (8 oz), more than 0.6 m (2.0 ft) across the wings and 25 cm (10 in) in length. The hummingbirds are also traditionally included in this order, the largest species of which is easily the Giant Hummingbird (Patagona gigas) of the Andes Mountains. "Giant" is a relative term among the hummingbirds, the smallest-bodied variety of birds, and this species weighs up to 24 g (0.85 oz) at a length of 23 cm (9.1 in). The longest hummingbird species, indeed the longest in the order, is the adult male Black-tailed Trainbearer (Lesbia victoriae), which can measure up to 25.5 cm (10.0 in), but a majority of this length is due to the extreme tail streamers. Another size champion among hummingbirds is the Sword-billed Hummingbird, a fairly large species in which about half of its 21 cm (8.3 in) length is from its enormous bill (easily the largest bill-to-body-size ratio of any bird).

The Great Potoo is, overall, the largest member of the order Caprimulgiformes.

• Nightjars and allies (Caprimulgiformes)

The largest species of this order of nocturnal, mysterious birds is the neotropical Great Potoo (Nycitbius grandis), the maximum size of which is about 680 g (1.5 lb) and 60 cm (2 ft). Heavier specimens have been recorded in the bulky Australian Tawny Frogmouth (Podargus strigoides) species, especially juvenile birds, which can weigh up to 1.4 kg (3.1 lb). Other species nearly as large as the potoo are the Papuan Frogmouth (Podargus papuensis) of New Guinea and the neotropic, cave-dwelling Oilbird (Steatornis caripensis), both at up to 48 cm (19 in). The largest species in the true nightjar family, the Great Eared-nightjar (Eurostopodus macrotis) of East Asia, is rather smaller at up to 150 grams (5.3 oz) and 41 cm (16 in). The wingspan in the Great Potoo and the Oilbird can be more than 1 m (3.3 ft), the largest of the order.

• Shorebirds (Charadriiformes)

The largest species in this diverse order is the Great Black-backed Gull (Larus marinus) of the North Atlantic, attaining a size of as much as 0.79 m (2.6 ft), a wingspan of 1.7 m (5.6 ft) and weighing up to 2.3 kg (5.1 lb). Among the most prominent family of "small waders", the sandpipers reach their maximum size in the Far Eastern Curlew (Numenius madagascariensis) at up to 0.66 m (2.2 ft) and 1.1 m (3.6 ft) across the wings, although the more widespread Eurasian Curlew (N. arquata) can weigh up to 1.36 kg (3.0 lb). Less variable in size, the plovers largest species is the Australasian Masked Lapwing (Vanellus miles) at up to 0.4 m (1.3 ft) long, a 0.85 m (2.8 ft) wingspan and a weight of 400 g (14 oz). The terns, previously considered members of the gull family, are usually slender and dainty-looking in comparison but the largest species, the widely distributed Caspian Tern (Hydroprogne caspia), is quite large and heavily built. Caspians can range up to 782 g (1.724 lb), a 1.4 m (4.6 ft) wingspan and 0.6 m (2.0 ft) in length. The alcids largest extant member is the sub-Arctic Thick-billed Murre (Uria lomvia), which can range up to 1.48 kg (3.3 lb), a length of 0.48 m (1.6 ft) and a small wingspan of 0.76 m (2.5 ft). However, until its extinction at mankind's hands, the flightless Great Auk (Pinguinus impennis) of the North Atlantic, was both the largest alcid and the largest member of the order. Great auks could range up to 6.8 kg (15 lb) and 0.9 m (3.0 ft) tall.

• Herons and allies (Ciconiiformes)

The new world vultures are still generally considered a member of this order, although the inclusion is dubious at best. If they are included, the largest species in the order, if measured in regard to body weight and wingspan, is the Andean Condor (Vultur gryphus) of western South America. The great bird can reach a wingspan of 3.2 m (10.7 ft) and a weight of 15 kg (33 lb). The longest-bodied and tallest species in the order is probably the slender, towering Saddle-billed Stork of Africa (Ephippiorhynchus senegalensis), which often exceeds 1.5 m (5 ft) tall and has a wingspan of up to 2.7 m (8.9 ft). Reaching a similar or slightly shorter height but more heavily built among the storks are the neotropical Jabiru (Jabiru mycteria), the Asian Greater Adjutant (Leptoptilos dubius) and the African Marabou Stork (L. crumeniferus), all of which are believed to weigh up to 8 to 9 kg (18 to 20 lb). The latter species, the Marabou, at least nearly equals the Andean condor in maximum wingspan, verified to 3.16 m (10.5 ft). These two species are regarded as having the largest wingspan of any landbirds (that is species who live over land as opposed to tied to the sea or wetlands). Standing up to nearly 1.53 m (5.0 ft), with a wingspan of up to 2.3 m (7.5 ft) and a weight up to 5 kg (11 lb) is the African Goliath Heron (Ardea goliath), the largest of the diverse and well-known herons and egrets. Many of the largest flying birds in the fossil record may have been members of the Ciconiiformes. This may include the largest flying bird ever, Argentavis magnificens, which is part of a group, the teratorns, that are considered an ally of the New World vultures.

• Mousebirds (Coliiformes)

The mousebirds of Africa are remarkably uniform, but the largest species is seemingly the Speckled Mousebird (Colius striatus), at 2 oz (60 g) and over 14 in (35 cm).

The Victoria Crowned Pigeon is the largest living pigeon.

• Pigeons (Columbiformes)

The largest species of the pigeon/dove complex is the Victoria Crowned Pigeon (Goura victoria) of Northern New Guinea, although the other crowned pigeons approach similar sizes. Some exceptionally large ones have reached 3.7 kg (8.2 lb) and 85 cm (34 in). The largest arboreal pigeon is the Marquesan Imperial-pigeon (Ducula galeata), which is up to about 0.55 m (1.8 ft), 0.8 m (2.6 ft) across the wings and can weigh 1 kilogram (2.2 lb). The flightless Dodo (Raphus cucullatus), endemic to the island Mauritius until humans and introduced animals carelessly hunted it into extinction, was the largest bird of this order of all time. These huge birds could have weighed up to 23 kg (51 lb) and could stand up to 1 m (3.3 ft) tall.

• Kingfishers and allies (Coraciiformes)

The largest species is the Southern Ground Hornbill (Bucorvus leadbeateri), reaching sizes of as much as 6.2 kg (14 lb) and 1.3 m (4.3 ft) in length. Several arboreal, Asian hornbills can grow very large as well, with the Great Hornbill (Buceros bicornis) growing to 4 kg (8.8 lb) and 1.2 m (3.9 ft). The larger hornbills have a wingspan of up to 1.83 m (6.0 ft). The largest kingfisher overall is the Giant Kingfisher (Megaceryle maxima), at up to 48 cm (19 in) long and 425 g (15.0 oz), with a large crest and finely spotted white on black upperparts. However, the common Australian species, the Laughing Kookaburra (Dacelo novaeguineae), may be heavier still, since individuals exceeding 453 g (0.999 lb) are not uncommon. A kookaburra wingspan can range up to 0.9 m (3.0 ft).

• Cuckoos and allies (Cuculiformes)

The largest species of this order is the Great Blue Turaco (Corythaeola cristata), a cousin of the better-known cuckoos. This species, which can weigh over 1.25 kg (2.8 lb) and measure over 0.74 m (2.4 ft) in length, is much larger than other turacos. The largest of the cuckoos is the Australasian Channel-billed Cuckoo (Scythrops novaehollandiae), which can range up to a weight of 0.93 kg (2.1 lb), a 1 m (3.3 ft) wingspan and a length of 0.66 m (2.2 ft).

• Falcons (Falconiformes)

Many authorities now support the split of falcons from the Accipitriformes, despite similar adaptations, due to the genetic evidence showing they are not closely related. The largest species of falcon is the Gyrfalcon (Falco rusticolus). Large females of this species can range up to 2.1 kg (4.6 lb), span 1.6 m (5.2 ft) across the wings and measure 0.66 m (2.2 ft) long.

• Gamebirds (Galliformes)

The heaviest member of this diverse order is the North American Wild Turkey (Meleagris gallopavo). The largest specimen ever recorded was shot in 2002, and weighed 16.85 kg (37.1 lb) and 1.44 m (4.7 ft) in total length. The heaviest domesticated turkey on record, a very obese bird, weighed 37 kg (81 lb). The longest species, if measured from the tip of the bill to the end of the long tail coverts, is the male Green Peafowl (Pavo muticus) of Southeast Asia, at up to 3 m (10 ft) long. This is the longest overall length for any flying bird, although about two-thirds of the length is comprised by the tail coverts, and this species (to 5 kg (11 lb)) weighs less than its cousin, the Indian Peafowl (P. cristatus), at up to 6 kg (13 lb). Although, wingspan is relatively small in most galliformes, wild turkey and green peafowl can span over 1.6 m (5.2 ft) across the wings. The largest member of the grouse family is the Eurasian Western Capercaillie (Tetrao urogallus), at up to 6.7 kg (15 lb) and 1 m (3.3 ft). A prehistoric, flightless family, sometimes called (incorrectly) "giant megapodes" (Sylviornis) of New Caledonia were the most massive galliformes ever, having reached 1.7 m (5.6 ft) long and weighed up to about 40 kg (88 lb).

• Loons (Gaviiformes)

The largest species on average is the Yellow-billed Loon (Gavia adamsii) of the Arctic, at up to 1 m (3.3 ft) and 7 kg (15.4 lb). However, one exceptionally large North American Common Loon (Gavia immer), weighed 8 kg (17.6 lb), heavier than any recorded Yellow-billed Loon. Wingspan in these largest loons can reach 1.52 m (5.0 ft).

Alongside the Great Bustard, the Kori Bustard is the heaviest extant flying bird.

• Cranes and allies (Gruiformes)

The males of the Eurasian Great Bustard (Otis tarda) and the African Kori Bustard (Ardeotis kori) are the heaviest birds capable of flight, averaging up to 16 kg (35 lb) and weighing 2 to 3 times as much as their female counterparts. It is not resolved if one of these species is larger than the other, but both can reach at least 21 kg (46 lb) and measure up to 1.53 m (5.0 ft) long. The tallest flying bird on earth, also represented in the Gruiformes, is the Sarus Crane (Grus antigone) of Southern Asia and Australia, which can reach a height of 2 m (6.6 ft). Heavier cranes are reported in other species, the Red-crowned Crane (Grus japonensis) and the Siberian Crane (G. leucogeranus), both from Northeast Asia and both at up to 15 kg (33 lb), as opposed to a top weight of 12.8 kg (28 lb) in the Sarus. Wingspan in both the largest cranes and the largest bustards can range up to 2.5 to 3 m (8.2–9.8 ft). The most species-rich family in this order, the rails, reaches their largest size in the Takahē (Porphyrio hochstetteri) of New Zealand, an endangered species that can weigh up to 4.2 kg (9.3 lb) and measure 0.65 m (2.1 ft) long. The afforement-mentioned "terror bird", Brontornis burmeisteri, has traditionally been classified as a member of this order, although this may not be an accurate classification.

The Thick-billed Raven shares the title of the largest songbird with its common cousin.

• Songbirds (Passeriformes)

The passerine or songbird order comprises more than half of all bird species, and are known for their generally small size, their strong voices and their frequent perching. Corvids are the largest of passerines, particularly the large races of the Common Raven (Corvus corax) and the Northeast African Thick-billed Raven (C. crassirostris), which are both equally enormous by songbird standards. Large ravens can weigh 2 kg (4.4 lb), attain a 1.53 m (5.0 ft) wingspan and measure 0.78 m (2.6 ft) long. The closest non-corvid contender to largest size is the Australian Superb Lyrebird (Menura novaehollandiae), which can reach a length of 1 m (3.3 ft), much of it comprised by their spectacular tail, and a weight of 1 kg (2.2 lb). The largest species in the most species-rich passerine family, Tyrannidae or tyrant-flycatchers, is the Great Shrike-Tyrant of the South Andes (Agriornis lividus), at 99.2 g (3.50 oz) and 31 cm (12 in), although the Fork-tailed Flycatcher (Tyrannus savana), to 41 cm (16 in), is longer thanks to its extreme tail. The namesake of the previous family, the Old World flycatchers, reaches its maximum size in the Green Cochoa of Southeast Asia (Cochoa viridis), if it is indeed a proper member of the family, at up to 122 g (4.3 oz) and a length of 29 cm (11 in). Closely related to the Old World flycatchers and internationally well-known, the thrush family's largest representative is the Blue Whistling-thrush of India and Southeast Asia (Myophonus caeruleus), at up to 230 g (8.1 oz) and 36 cm (14 in). The largest bird family in Eurasia is the Old World warblers. As previously classified these warblers could get fairly large, up to 57 g (2.0 oz) and 28 cm (11 in) in the Striated Grassbird of Southeast Asia (Megalurus palustris). The Old World warblers have been split into several families, however, which leaves the Barred Warbler of central Eurasia (Sylvia nisoria), up to 36 g (1.3 oz) and 17 cm (6.7 in), as the largest "true warbler". Not to be confused with the previous family, the largest of the well-known New World warblers is the aberrant Yellow-breasted Chat (Icteria virens), which can measure up to 22 cm (8.7 in) and 53 g (1.9 oz). Another large family is the bulbuls, the largest of which is the south Asian Straw-headed Bulbul (Pycnonotus zeylanicus), to 94 g (3.3 oz) and 29 cm (11 in). The diverse, large family of babblers can reach 35 cm (14 in) and 170 g (6.0 oz) in the south Asian Greater Necklaced Laughingthrush (Garrulax pectoralis). The familiar domesticated species, the Java Sparrow (Padda oryzivora), is (in the wild) the largest estrild, at up to 28.3 g (1.00 oz) and 17 cm (6.7 in). The largest honeyeater, perhaps the most diverse Australasian bird family, is the Crow Honeyeater (Gymnomyza aubryana), at up to 290 g (10 oz) and 30 cm (12 in). The largest of the "true finches" is the Collared Grosbeak (Mycerobas affinis) of central and south Asia at up to 23 cm (9.1 in) and 80 g (2.8 oz). Among the largest bird families, the emberizids, reaches its largest size in the Abert's Towhee (Pipilo aberti) of Southwest United States and north Mexico at up to 23 cm (9.1 in) and 54 g (1.9 oz). Closely related to the previous family is the tanagers, which can range up to 140 g (4.9 oz) in the Andean-forest-dwelling White-capped Tanager (Sericossypha albocristata). Another species-rich neotropical family is the ovenbirds, the largest of which, the Great Rufous Woodcreeper (Xiphocolaptes major) of the Amazonian rainforests, can weigh up to 162 g (5.7 oz) and 35 cm (14 in). The specialized antbird family can range up to 156 g (5.5 oz) in the Giant Antshrike (Batara cinerea). Among the most variably sized passerine families is the icterids. The largest icterid is the Amazonian Oropendola (Psarocolius bifasciatus), in which males can range up to 52 cm (1.71 ft) and 550 g (1.21 lb). The latter species competes with the similarly sized Amazonian Umbrellabird (Cephalopterus ornatus) as the largest passerine in South America.

The Dalmatian Pelican is one of the world's largest flying birds.

• Cormorants and allies (Pelecaniformes)

The pelicans rank amongst the largest flying birds. The largest species of pelican is the Eurasian Dalmatian Pelican (Pelecanus crispus), which attains a length of 1.83 m (6.0 ft) and a body weight of 15 kg (33 lb). The Great White Pelican (P. onocrotalus) of Europe and Africa is nearly as large. The Australian Pelican (P. conspicillatus) is slightly smaller but has the largest bill of any bird, at as much as 49 cm (19 in) long. A large pelican can attain a wingspan of 3.6 m (11.8 ft), second only to the great albatrosses among living birds. The largest of the cormorants is the Flightless Cormorant of the Galapagos Islands (Phalacrocorax harrisi), at up to 5 kg (11 lb) and 1 m (3.3 ft), although large races in the Great Cormorant (P. carbo) can weigh up to 5.3 kg (12 lb). The Spectacled Cormorant of the North Pacific (Phalacrocorax perspicillatus), which went extinct around 1850, was larger still, growing to at least 6.4 kg (14 lb) and 1.15 m (3.8 ft). The widely distributed Magnificent Frigatebird is of note for having an extremely large wingspan, up to 2.5 m (8.2 ft), for its relatively light body, at up to only 1.9 kg (4.2 lb). A bird of the late Miocene from the North Pacific, Osteodontornis, has traditionally been classified as a pelecaniform, though this may be in error. This giant was among the largest flying birds ever, at up to 2.1 m (7 ft) long with a wingspan of 6 m (20 ft).

• Flamingos (Phoenicopteriformes)

The largest flamingo is the Greater Flamingo (Phoenicopterus ruber) of Eurasia and Africa. One of the tallest flying birds in existence when standing upright (exceeded only by the tallest cranes), this species typically weighs 3.5 kg (7.7 lb) and stands up to 1.53 m (5.0 ft) tall. However, at maximum size, a male can weigh up to 4.55 kg (10.0 lb) and stand as high as 1.87 m (6.1 ft). Wingspan is relatively small in flamingos, but can range up to 1.65 m (5.4 ft).

The Toco Toucan is the largest species in the Piciformes order as well as one of the most colorful.

• Woodpeckers and allies (Piciformes)

The largest species of this diverse order is the Toco Toucan (Ramphastos toco) of the neotropic forest. Large specimens of this toucan can weigh to 870 g (1.92 lb) and 0.65 m (2.1 ft), at which size the magnificent beak alone could measure about 20 cm (7.9 in). The largest woodpecker was, at least until the 20th century, the Imperial Woodpecker (Campephilus imperialis) of Mexico. This species had a length of up to 0.6 m (2.0 ft) and is generally believed to have gone extinct following habitat destruction and hunting. The closely related Ivory-billed Woodpecker (Campephilus principalis) of the Southeast United States and Cuba approached similar sizes at up to 0.5 m (1.6 ft), a 0.78 m (2.6 ft) wingspan and a mass of at least 530 g (1.17 lb). Despite possibilities that it has survived in some deep swamp forests in Arkansas or Florida, the Ivory-billed is generally considered to have succumed to the same man-made pressures as its larger cousin. Fairing better so far, the Great Slaty Woodpecker (Mulleripicus pulverulentus) of southeast Asia is the largest woodpecker certain to exist, with a weight of up to 500 g (1.1 lb) and a length of up to 0.58 m (1.9 ft). Less well-known than the woodpeckers and toucans, the barbets can range up to 273 g (9.6 oz) and 33 cm (13 in) in the Great Barbet (Megalaima virens).

• Grebes (Podicipediformes)

The largest species of grebe is the South American Great Grebe (Podiceps major). It can reach a length of 0.8 m (2.6 ft), a 1 m (3.3 ft) wingspan and a weigh of over 2 kg (4.4 lb).

The Wandering Albatross is the largest sea bird

• Tubenoses (Procellariiformes)

The largest species is Wandering Albatross (Diomedea exulans) of the sub-Antarctica oceans, which also possesses longest wingspan of any living bird. The maximum dimensions are a length of 1.44 m (4.6 ft) and a wingspan of 3.65 m (12.0 ft). The Southern Royal Albatross (Diomedea epomophora) lags behind the Wandering only slightly in all aspects of size. Flying on enormous wings, these great birds can fly for hours on the ocean winds without flapping or needing to land. Immature wandering albatrosses have weighed as much as 15.9 kg (35 lb) at the time of their first flights. The largest-ever tubenose (though it is sometimes classified in the order Pelecaniformes and at other times in a separate, extinct order) was the albatross-like Gigantornis eaglesomei, found in fossils from the Eocene era in what is now Nigeria, with a wingspan of about 6 m (20 ft).

• Hoatzin (Opisthocomiformes)

The Hoatzin (Opisthocomus hoazin), Hoatzin is a pheasant-sized South American bird, with a total length of 65 centimetres (26 in) and a maximum weight of 1 kg (2.2 lb), and has a long neck and small head. It has an unfeathered blue face with maroon eyes, and its head is topped by a spiky, rufous crest. The long sooty-brown tail is broadly tipped buff. The upperparts are dark sooty-brown edge

• Parrots (Psittaciformes)

The largest parrot by length and wingspan is the endangered Hyacinth Macaw (Anodorhynchus hyacinthinus) of the neotropic lowlands, reaching a length of nearly 1.2 m (3.9 ft) long, and a wingspan of 1.4 m (4.6 ft); it weighs only 2 kg (4.4 lb). The heaviest parrot is the nearly extinct Kakapo (Strigops habroptila), which is part of the unique New Zealand parrot family. The strange, flightless kakapo may not exceed 0.68 m (2.2 ft) in length, it can however weigh over 4 kg (8.8 lb). The largest species in the cockatoo family is the Australasian Palm Cockatoo (Probosciger aterrimus), at up to 0.6 m (2.0 ft) long and a weight of 1.2 kg (2.6 lb).

• Sandgrouse (Pterocliformes)

The Black-bellied Sandgrouse (Pterocles orientalis) is the largest sandgrouse, at a maximum size of 634 g (1.4 lb) and 45 cm (18 in).

The Emperor Penguin is one of the heaviest living birds as well as the largest penguin.

• Penguins (Sphenisciformes)

The largest species is easily the Emperor Penguin (Aptenodytes forsteri) of the Antarctic, with a maximum height of 1.35 m (4.3 ft) and weight of 46 kg (102 lb). The next largest living species is the King Penguin, which grows up to a maximum of 18 kg (40 lb) and 1 m (3.3 ft) tall. At one time, possibly competing with the mammalian pinnipeds, a number of giant penguins existed. The largest is believed to be Anthropornis nordenskjoeldi, having reached a height of 1.8 m (5.9 ft) and a weight of up to 108 kg (238 lb).

The Eurasian Eagle Owl is one of the biggest owls

• Owls (Strigiformes)

The most massive owl is certainly either the Eurasian Eagle Owl (Bubo bubo) or the endangered and similarly sized Blakiston's Fish Owl (Bubo blakistoni) of coastal Russia and Japan. Record-sized specimens of both species have weighed about 4.5 kg (10 lb) and measured over 0.75 m (2.5 ft). In large Eurasian Eagle Owls, the wingspan can range up to 2 m (6.6 ft). Longer still, but not as massive as the previous species (never more than 1.8 kg (4.0 lb) in weight), a large female Great Gray Owl (Strix nebulosa) from the northern boreal forests can range up to 0.83 m (2.7 ft). The largest of the barn or masked owl family is the Tasmanian subspecies (possibly full species) of the Australian Masked Owl (Tyto novaehollandiae castanops), which weighs up to 1.4 kg (3.1 lb) and measures to 0.6 m (2.0 ft). The largest owl known to have existed was Ornimegalonyx oteroi of Cuba, a uniquely cursorial owl. The giant bird was estimated to stand over 1.1 m (3.6 ft) on the ground and to weigh at least 9.05 kg (20.0 lb).

In a order of elusive, forest dwelling birds, the Gray Tinamou ranks as the largest species

• Tinamous (Tinamiformes)

The largest species of tinamou, a group of chunky, elusive ground-birds from the neotropical forests, is the Grey Tinamou (Tinamus tao) of western South America. It can reach a weight over 2 kg (4.4 lb) and length of over 55 cm (22 in).

• Trogons (Trogoniformes)

The Resplendent Quetzal (Pharomachrus mocinno) of the montane cloud of Central America is the largest trogon, though a few other quetzals approach similar sizes. It can weigh more than 226 g (8.0 oz) and, in females and non-breeding or immature males, measure up to 0.4 m (1.3 ft) from the head to the tail. However, when the adult male develops his spectacular tail streamers, his total length is boasted an extra 0.6 m (2.0 ft).

Amphibians (Amphibia)

Main article: Largest amphibians

A giant salamander, the largest of the surviving amphibians.

The largest living amphibian is the Chinese Giant Salamander (Andrias davidianus). The maximum size of this nearly man-sized river-dweller is 64 kg (140 lb) and almost 1.83 m (6.0 ft). Before amniotes became the dominant tetrapods, several giant amphibian-like tetrapods existed and were certainly the dominant animals in their ecosystems. The largest known was the crocodile-like Prionosuchus, which reached a length of 9 m (30 ft).

• Frogs (Anura)

The largest member of the largest order of amphibians is the African Goliath frog (Conraua goliath). The maximum size this species is verified to attain is a weight of 3.8 kg (8.4 lb) and a snout-to-vent length of 39 cm (15 in). The largest of the toads, the Cane Toad (Bufo marinus), is also the second largest member of the frog order. This infamous, often invasive species can grow to maximum mass of 2.65 kg (5.8 lb) and measure a maximum of 33 cm (13 in) from snout-to-vent. Rivaling the previous two species, the African Bullfrog (Pyxicephalus adspersus) can range up to a weight of 2 kg (4.4 lb) and 25.5 cm (10.0 in) from snout to vent. However, the toad Beelzebufo ampinga, found in fossil from the Cretaceous era in what is now Madagascar, could grow to be 41 cm (16 in) long and weigh up to 4.5 kg (10 lb), making it the largest frog ever known. The largest tree frog is the Australasian White-lipped Tree Frog (Litoria infrafrenata), the females of which can reach a length of 14 cm (5.5 in) from snout to vent and can weigh up to 115 g (4.1 oz). The largest horned or "Pacman frog" is the Surinam horned frog (Ceratophrys cornuta), which can reach 20 cm (7.9 in) in length from snout to vent and weigh up to 0.48 kg (1.1 lb). The largest dendrobatid is the Colombian Golden Poison Frog (Phyllobates terribilis), which can attain a length of 6 cm (2.4 in) and nearly 28.3 g (1.00 oz). Most frogs are classified under the suborder Neobatrachia, although nearly 200 species are part of the Mesobatrachia suborder, or ancient frogs. The largest of these are the little known Brachytarsophrys or Karin Hill frogs, of South Asia, which can grow to a maximum snout-to-vent length of 17 cm (6.7 in) and a maximum weight of 0.54 kg (1.2 lb).

The massive and destructive Cane Toad ranks as the largest toad in the world

• Caecilians (Gymnophiona)

The largest of the worm-like caecilians is the Colombian Thomson's Caecilian (Caecilia thompsoni), which reaches a length of 1.5 m (5 ft), a width of about 4.6 cm (1.8 in) and can weigh up to about 1 kg (2.2 lb).

• Salamanders (Urodela)

Besides the previously mentioned Chinese Giant Salamander, the closely related Japanese Giant Salamander (Andrias japonicus) is also sometimes cited as the largest living amphibian, but salamanders of a greater size than 1.53 m (5.0 ft) and 36 kg (79 lb) have never been verified for this species. Another giant of the amphibian world is the North American Hellbender (Cryptobranchus alleganiensis), which can measure up to 0.76 m (2.5 ft). The largest of the newts is the Iberian Ribbed Newt (Pleurodeles waltl), which can grow up to 30 cm (12 in) in length.

Lobe-finned fish (Sarcopterygii)

The coelecanth is one of the strangest and most primitive fish

The largest living lobe-finned fish is the coelecanth. The average weight of the living West Indian Ocean coelacanth, (Latimeria chalumnae), is 80 kg (176 lb), and they can reach up to 2 m (6.5 ft) in length. Specimens can measure up to 110 kg (240 lb). The largest lobe-finned fish of all time was Hyneria at up to 5 m (16 ft).

• Lungfish (Dipnoi)

The largest lungfish, the African lungfish (Protopterus aethiopicus), is smooth, elongated, and cylindrical with deeply embedded scales. The tail is very long and tapers at the end. They can reach a length of up to 2 m (6.6 ft) and may weigh as much as 50 kg (110 lb). The pectoral and pelvic fins are also very long and thin, almost spaghetti-like. The newly hatched young have branched external gills much like those of newts. After 2 to 3 months the young transform (called metamorphosis) into the adult form, losing the external gills for gill openings. These fish have a yellowish gray or pinkish toned ground color with dark slate-gray splotches, creating a marbling or leopard effect over the body and fins. The color pattern is darker along the top and lighter below.

Ray-finned bony fish (Actinopterygii)

The ocean sunfish is the largest of the bony fish

The largest living bony fish is the widely distributed ocean sunfish (Mola mola), a member of the order Tetraodontiformes. The record size sunfish crashed into a boat off Bird Island, Australia in 1910 and measured 4.3 m (14 ft) from fin-to-fin, 3.1 m (10 ft) in length and weighed about 2,300 kg (5,100 lb). Much larger bony fish existed prehistorically, the largest ever known having been Leedsichthys, of the Jurassic period in what is now England. This species is certainly the largest bony fish ever perhaps the largest non-cetacean marine animal to have ever existed. Estimates of the size of this fish range from 9 m (30 ft) to 30 m (100 ft), but a maximum size of 22 m (72 ft) seems most realistic.

The remains of a 1000 kg beluga sturgeon, one of the largest bony fish

• Sturgeons (Acipenseriformes)

The largest species is the huge beluga sturgeon (Huso huso) of the Caspian and Black seas, the main extant rival to the largest size in bony fish to the Ocean Sunfish. The largest specimen considered reliable (based on remains) was caught in Volga estuary in 1827 and measured 7.3 m (24 ft) and weighed 1,474 kg (3,250 lb). The slightly smaller Kaluga (Huso dauricus) or Great Siberian Sturgeon has been weighed reliably up to 1,140 kg (2,510 lb) (Berg, 1932). The North American White Sturgeon (Acipenser transmontanus), unverified to 907 kg (2,000 lb), and the Russian sturgeon (Acipenser gueldenstaedtii), at as much as 1,000 kg (2,200 lb) for a 75-year-old female, also can attain great sizes. These fish are sometimes called the largest freshwater fish but sturgeons spend a great deal of time in brackish water and switch back and forth between saltwater and freshwater environments in their life cycle. Also included in this order are the paddlefish and the Chinese Paddlefish (Psephurus gladius), which may now be extinct and is at least critically endangered, is also a very large fish. Reportedly, fisherman as recently as the 1950s have caught fish measuring up to 6.7 m (22 ft) in total length, although no specimen greater than 3.1 m (10 ft) has been scientifically measured. Weight is reportedly 300 to 500 kg (660 to 1,100 lb).

The head of a European conger, the world's most massive eel

• Eels (Anguilliformes)

The largest species of "true eel", if measured in weight and overall bulk, is the European conger (Conger conger). The maximum size of this species has been reported to 3 m (9.8 ft) and a mass of 110 kg (240 lb). Several moray eels can equal or exceed the previous eel in length but do not weigh as much. The longest fish in the order, at up to 4 m (13 ft), is the Slender giant moray (Strophidon sathete) of the Indo-Pacific oceans.

• Silversides (Atheriniformes)

An order best known for its tiny representatives, the largest species is the jacksmelt (Atherinopsis californiensis) of the Pacific Ocean. Although it reaches 45 cm (18 in), it is not known to even reach 450 g (1 lb).

• Grinners (Aulopiformes)

The largest member of this order is the lancetfish (Alepisaurus ferox), found in all the world's oceans. Slender, with a huge, dramatic spine, these fish can reach 2.1 m (7 ft) long and can weigh up to 11 kg (24 lb).

• Toadfish (Batrachoidiformes)

The largest toadfish, the Pacuma toadfish.

The largest toadfish is the Pacuma toadfish (Batrachoides surinamensis), reaching a size of up to 5 lb (2.3 kg) and 23 in (58 cm).

• Flying-fish and allies (Beloniformes)

The largest member of this order, best known for its members' ability to breach the water and zip through the sky, is the pelagic Houndfish (Tylosurus crocodilus), a slender fish at up to 1.5 m (5 ft) and a weight of 6.35 kg (14.0 lb). The largest true "flying fish" is the Japanese Flying Fish (Cheilopogon pinnatibarbatus japonicus), which can range up to 0.5 m (1.6 ft) in length and weigh over 1 kg (2.2 lb).

• Squirrelfish (Beryciformes)

Best known for their highly poisonous barbs, the squirrelfish's largest representative is the giant squirrelfish (Sargocentron spiniferum) of the tropical oceans, at up to 61 cm (24 in) and 3.5 kg (7.7 lb).

• Characins (Characiformes)

The largest species is the African freshwater fish, the giant tigerfish (Hydrocynus goliath). The top size of this fish is 1.5 m (5 ft) and 50 kg (110 lb). Among the largest of the characin family is the popular sport-fish, the Golden Dorado (Salminus brasiliensis), which can reach up to 1 m (3.3 ft) in length and weigh 31.4 kg (69 lb). Among the characins are the infamous neotropical piranhas. Carnivorous species can grow up to 0.43 m (1.4 ft), although the Tambaqui (Colossoma macropomum), at up to 1 m (3.3 ft) and 32.4 kg (71 lb), is often considered a giant, herbivorous form of piranha.

• Herring (Clupeiformes)

The largest herring is probably the Dorab wolf herring (Chirocentrus dorab) of the Indo-Pacific oceans. The maximum size of this species has been reported as much as 1.8 m (6 ft), but these slender fish have never been recorded as exceeding 3.4 kg (7.5 lb) in weight.

• Minnows and allies (Cypriniformes)

The minnow family (which includes carp), Cyprinidae, is the largest family of vertebrates, with over 2400 species known today. The largest species is probably the giant barb (Catlocarpio siamensis), which is endemic to three river basins in central Asia and reaches a size of as much as 3 m (10 ft) and a weight of as much as 300 kg (660 lb). In centuries past, the Mahseer (Barbus tor) of Southern Asia was reported to reach similar or even larger proportions in old records, but these are dubious since specimens nearly as large as the giant barb have never been reported in recent centuries.

• Pikes and allies (Esociformes)

The largest species in this small but interesting order (formerly allied with the salmonids) is the Muskellunge (Esox masquinongy) of the rivers of North America. These predatory fish can grow up to 1.83 m (6.0 ft) and 45.4 kg (100 lb).

• Killifish and allies (Cyprinodontiformes)

The largest species in this relatively small-bodied order is the Pacific four-eyed fish (Anableps dowei), reaching a size of 34 cm (13 in) and 588 g (1 lb 4¾ oz).

• Ladyfishes and allies (Elopiformes)

This small order is usually considered closely related to the true eels although its members are very different in appearance and behavior from eels. The largest species is much-coveted-sport fish, the Atlantic tarpon (Megalops atlanticus). The maximum recorded size for this species is 161 kg (355 lb) and length is up to 2.5 m (8.2 ft).

• Cod (Gadiformes)

The largest cod, the Atlantic cod.

The largest cod species, although it rarely reaches large sizes anymore due to heavy fishing, is the Atlantic cod (Gadus morhua). The maximum size of this species is 2 m (6.7 ft) long and 96 kg (212 lb).

• Sticklebacks and allies (Gasterosteiformes)

The largest form of stickleback, a small, cylindric type of fish, is the Sea stickleback or Fifteenspine stickleback (Spinachia spinachia). This species can range up to 22 cm (8.7 in) in length and weigh up to 8.5 g (0.30 oz).

• Clingfish (Gobiesociformes)

These bottom-dwelling fish reach their maximum size in Sicyases sanguineus. This species can reach 30 cm (12 in) in length and weigh up to 1 kg (2.2 lb).

• Shellears and allies (Gonorynchiformes)

The well-known milkfish (Chanos chanos) is the largest member of this order. The maximum size is 22.7 kg (50 lb) and 1.84 m (6.1 ft) long.

• Mooneyes (Hiodontiformes)

Only two extant species are known to exist in this relatively new order. The larger of the two is the Goldeye (Hiodon alosoides) from the northern rivers of North America, which can reach up to 0.52 m (1.7 ft) in length and can weigh 1.8 kg (4.0 lb).

• Ribbonfish and allies (Lampriformes)

The largest ribbonfish, the King of herrings.

The largest member of this small but fascinating order is the King of herrings or oarfish (Regalecus glesne), also the longest bony fish on earth. Slender and compressed, this fish averages over 6 m (20 ft) long at maturity. A specimen caught in 1885 of 7.6 m (25 ft) in length weighed 275 kg (606 lb). The longest known king of herrings, which was hit by a steamship, was measured as 13.7 m (45 ft) long, but unverified specimens have been reported up to 16.7 m (55 ft). Another interesting big fish in this order is the Opah (Lampris guttatus), which as opposed to the king of herrings, is massive and has a chunky, rounded shape. Opahs can range up to 2 m (6.6 ft) in length and weigh up to 270 kg (600 lb).

A large alligator gar, the largest freshwater fish in North America

• Gars (Lepisosteiformes)

The largest of the gar, and the largest entirely freshwater fish in North America, is the alligator gar (Atractosteus spatula). The largest gar ever known, caught in Louisiana in 1925, was 3 m (9.8 ft) in length and weighed 137 kg (302 lb).

• Anglerfish (Lophiiformes)

The largest of this diverse order is the common goosefish (Lophius piscatorius) of the Northeastern Atlantic off of Europe and North Africa. This big-mouthed fish can attain a size of 58 kg (127 lb) and a length of 2 m (6.6 ft).

• Lanternfish (Myctophiformes)

The largest of the numerous but small lanternfish is Bolin's lanternfish (Gymnoscopelus bolini) of the Indo-Pacific oceans, at up to 249 g (8.8 oz) and 35 cm (14 in).

• Pearlfish and allies (Ophidiiformes)

The largest member of this order is the widely distributed giant cuskeel (Lamprogrammus shcherbachevi). A cuskeel can be nearly 2 m (6.7 ft) long, but even large fish probably aren't much over 10 kg (22 lb) since they are quite slender.

• Bony-tongued fish (Osteoglossiformes)

The largest species is the South American fish usually known as the arapaima (Arampaima gigas). The maximum size this species can attain is a matter of some controversy and some rank it among the world's largest freshwater fishes. No individual arapaima over 3 m (9.8 ft) has been verified and measured. The skeleton of a fish reported to have been measured by native hunters as 4.5 m (15 ft) and weighing 200 kg (440 lb) when caught, was later examined as a skeleton scientifically and was found to have been roughly within that outsized dimension.

The Atlantic blue marlin is one of the largest species of the perch-like fish.

• Perches and allies (Perciformes)

The title of the largest member of this order, the most numerous order of all vertebrates, is a matter of some debate. A large marlin is the biggest of these fishes: the black marlin (Makaira indica) of the Indo-Pacific, the Atlantic blue marlin (Makaira nigricans) and the Indo-Pacific blue marlin (Makaira mazara). All of these species can exceptionially reach up to 5 m (16 ft) in length and weight may be as much as 907 kg (2,000 lb) or even 1,106 kg (2,438 lb). Another notable giant of the perch order is the Atlantic bluefin tuna (Thunnus thynnus) of the Northern Atlantic ocean, which has been verified at up to 4.4 m (14 ft) and 679 kg (1,497 lb), although can reportedly reach 910 kg (2,010 lb). The Swordfish (Xiphias gladius) can reach a maximum size of 650 kg (1,430 lb) and 4.5 m (15 ft). Due to heavy fishing of both species, swordfish and tuna of great sizes are increasingly rare. One of the largest freshwater fishes is the Nile Perch (Lates niloticus), which grows up to 200 kg (440 lb) and 2 m (6.6 ft). The biggest of snappers is the Cubera snapper (Lutjanus cyanopterus) of the Caribbean sea and east coast of South America, at a maximum size of 57 kg (126 lb) and 1.6 m (5.2 ft) in length. The largest species of grunt is the White margate (Haemulon album) of the Caribbean sea and east coast of South America, at up to 7.14 kg (15.7 lb) and 0.8 m (2.6 ft) in length. The blennies can range up to 0.55 m (1.8 ft) in the Hairtail Blenny (Xiphasia setifer) of the Indo-Pacific. The jacks or mackerels reach their maximum size in the Narrow-barred Spanish mackerel (Scomberomorus commerson), which can attain 70 kg (150 lb) and 2.4 m (7.9 ft). The most large butterflyfish are either the Lined butterflyfish (Chaetodon lineolatus) or the Saddle butterflyfish (C. ephippium), both of the Indo-Pacific and both of which can measure up to 30 cm (12 in). The Freckled darter (Percina lenticula) of the United States, the biggest of the darters, reaching 20 cm (7.9 in) and 70 g (2.5 oz). The largest drum is the Totoaba (Totoaba macdonaldi) of the Gulf of California, at up to 100 kg (220 lb) and 2 m (6.6 ft) long. Among the sea bass or groupers, many of which can grow quite large, the greatest size are reached in the huge Atlantic goliath grouper (Epinephelus itajara), which reaches a maximum known size of 455 kg (1,003 lb) and 2.5 m (8.2 ft). The species-rich cichlids reaches their maximum size in the East African Giant Cichlid (Boulengerochromis microlepis), at up to 0.8 m (2.6 ft) long and 5 kg (11 lb). The Humphead wrasse (Cheilinus undulatus) of the Indo-Pacific's coral reefs is by far the largest wrasse, and it can reach a maximum size of 191 kg (421 lb) and 2.3 m (7.5 ft). Among a fairly small-bodied family, the damselfishes, the Garibaldi (Hypsypops rubicundus) of the Pacific coast of America is the biggest, reaching up to 35.5 cm (14.0 in) and 1.2 kg (2.6 lb). The Marbled sleeper (Oxyeleotris marmorata) of East Asia is the largest member of the family or sub-order that almost certain contains the smallest living vertebrate, and can reach 0.66 m (2.2 ft) long and weigh 9.9 kg (22 lb).

• Trout-perch and allies (Percopsiformes)

The largest species in this small order (both by number of species and body size) is the Sand roller (Percopsis transmontana) of North America. This species can range up to 20 cm (7.9 in) in length and can weigh over 11 g (0.39 oz).

The Pacific halibut, largest of the flatfish, displays its effective camouflage.

• Flatfish (Pleuronectiformes)

The largest of the well-known and heavily fished flatfish is the Pacific halibut (Hippoglossus stenolepis). This giant can reach 363 kg (800 lb) and 3 m (9.8 ft), although fish even approaching this size would be extraordinary these days. The Atlantic halibut (Hippoglossus hippoglossus) is also sometimes titled the largest flatfish, although it has a slightly smaller maximum size, at 320 kg (710 lb) and 2.76 m (9.1 ft).

• Beardfish (Polymixiiformes)

The little-known beardfish are sometimes classified with the Beryciformes. The largest beardfish is Polymixia busakhini of the Indo-Pacific, which can range up to 0.57 m (1.9 ft) in length.

The Chinook salmon is one of the largest species of salmon.

• Salmon and allies (Salmoniformes)

The largest species of salmonid is the Taimen (Hucho taimen). The biggest taimen known was a huge fish, from the Kotui River in Russia, measuring 2.1 m (6.9 ft) and weighing of 105 kg (231 lb). Some sources claim the largest is the Chinook salmon (Oncorhynchus tshawytscha) of America's Pacific Northwest, although this species falls behind the taiman in maximum size. The maximum size of this fish is 61.4 kg (135 lb) and 1.5 m (5 ft) long.

• Sculpins (Scorpaeniformes)

Although less venomous than many smaller fish in the same order, the skilfish (Erilepis zonifer) of the North Pacific, is largest sculpin. The maximum size is 1.9 m (6.2 ft) and the weight can be up to 91 kg (201 lb). The Lingcod (Ophiodon elongatus) of the west coast of North America is sometimes listed as the largest sculpin but it is not known to exceed 1.52 m (5.0 ft) in length or 60 kg (130 lb) in weight. The Cottidae can range up to 0.72 m (2.4 ft) and 11 kg (24 lb) in the Cabezon (Scorpaenicthys marmoratus) of coastal North America.

A good-sized wels catfish is a rival for the title of the largest catfish.

• Catfish (Siluriformes)

Most authorities now give the crown of the largest catfish to the Mekong giant catfish, Pangasianodon gigas, which is also considered the heaviest completely freshwater fish. This huge fish has been recorded at sizes up to 350 kg (770 lb) and 3 m (9.8 ft). Closely related to that species, the Asian Giant pangasius (Pangasius sanitwongsei) can grow to 3 m (9.8 ft) and 300 kg (660 lb). However, the wels catfish (Silurus glanis) of Europe, at least challenges the proceeding species in massiveness and may surpass them in length. While wels have been confirmed to 3.1 m (10 ft), other whiskered giants have been reliably reported to grow to 3.7 m (12 ft) and 265 kg (584 lb) and more dubiously to 4.3 m (14 ft). Another giant of the catfish world is the South American Brachyplatystoma filamentosum, which can reportedly reach 3.6 m (12 ft) and 200 kg (440 lb).

The largest bristlemouth, the Short-tailed barbeled dragonfish

• Ridgeheads and allies (Stephanoberyciformes)

Known for flesh that fells flabby to the touch, this order reaches largest sizes in the Flabby Whalefish (Gyrinomimus grahami) of all southern oceans. This species, which can range up to 0.45 m (1.5 ft) in length, is sometimes commercially fished.

• Bristlemouths (Stomiiformes)

The largest of the deep-sea bristlemouths is the short-tailed barbeled dragonfish (Oppostomias micripnus). The top size of a female of this species is probably over 452 g (1 lb) and 50 cm (20 in) long. In species like the Barbeled dragonfish (Idiacanthus atlanticus), the worm-like females can measure up to 0.53 m (1.7 ft) long, about 50 times as long as the male. Although Idiacanthus is much more slender and is lighter than Oppostomias.

• Swamp-eels (Synbranchiformes)

The tropic-dwelling swamp-eels, which are not closely related to true eels, reaches their largest size in the Marbled swamp eel (Synbrachus marmoratus) of Central and South America. This fish can range up to 1.5 m (4.9 ft).

• Seahorses and allies (Syngnathiformes)

The largest of this diverse order is the red cornetfish (Fistularia petimba), a long, thin species found in all tropical oceans. This fish can reach a length of 2 m (6.6 ft) and a weight of 4.65 kg (10.3 lb). The largest of the famous, petite seahorses is the Big-belly seahorse (Hippocampus abdominalis) found off of Australia and New Zealand, which can grow to 35 cm (14 in) high and weigh over 60 g (2.1 oz).

• Dories (Zeiformes)

The largest species of dory is the Cape dory (Zeus capensis) reaching a size of 90 cm (36 in) and a weight of 20 kg (44 lb).

Cartilaginous fish (Chondrichthyes)

A size comparison of a whale shark and a human.

The cartilaginous fish are not directly related to the "bony fish", but are sometimes lumped together for simplicity in description. The largest living cartilaginous fish, of the order Orectolobiformes, is the whale shark (Rhincodon typus), of the world's tropical oceans. It is also the largest living animal that is not a cetacean and, like the largest whales, it is a docile creature that filter-feeds on tiny plankton. Average adult species are 9.7 m (32 ft) long and weigh an average of 9 metric tons (9.9 short tons). The largest verified specimen was caught in 1949 off Karachi, Pakistan and was 12.7 m (42 ft) long and weighed 21.5 metric tons (23.7 short tons). Although many are dubious, there are several reports of larger whale sharks, with reliable sources citing unverified specimens of up to 37 metric tons (41 short tons) and 17 m (56 ft).

A large Tiger shark ranks as the biggest of ground sharks.

• Ground sharks (Carcharhiniformes)

The largest species of this order is the widely distributed tiger shark (Galeocerdo cuvier). Specimens have been verfied to at least 5.5 m (18 ft) but even larger ones have been reported. One specimen, a gravid female caught off Australia and measuring only 5.5 m (18 ft) long, weighed 1,524 kg (3,360 lb). A female caught in 1957 was reported as 7.4 m (24 ft) and weighing 3,110 kg (6,860 lb), although this has not been confirmed. The largest of the infamous "requiem sharks" (in the Carcharhinus genus) seems to be the Dusky Shark (C. obscurus), at up to 4.2 m (14 ft), although the bulkier Bull Shark (C. leucas) has been estimated to weigh about 575 kg (1,268 lb) in recent specimens that measured over 4 m (13 ft) long. The largest hammerhead shark is the Great Hammerhead (Sphyrna mokarran), which can reach 6.1 m (20 ft) and weigh 500 kg (1,100 lb). The most species-rich shark family, the catsharks, are fairly small-bodied. The largest, the Nursehound (Scyliorhinus stellaris), can grow up to 1.7 m (5.6 ft).

• Chimaeras (Chimaeriformes)

These odd, often translucent cartilaginous fish are typically quite small. The largest species is the Carpenter's chimaera (Chimaera lignaria) of the oceans near Australia and New Zealand. It can reach up to 1.5 m (4.9 ft) in length.

• Bramble sharks (Echinorhiniformes)

These two, prickly-skinned species have been traditionally classified with the squalids, but are now considered unique. The larger species is the Prickly shark (Echinorhinus cookei), a bottom-dwelling shark of the Pacific ocean. They can reach a maximum length of 4 m (13 ft). This species can weigh over 266 kg (586 lb).

• Frill sharks and Cow sharks (Hexanchiformes)

The largest frill sharks and cow shark is the Bluntnose sixgill shark (Hexanchus griseus). This large species typically inhabits depths greater than 90 m (300 ft), and has been recorded as deep as 1,875 m (6,150 ft). The largest specimen known (caught off of Cuba) reportedly weighed 763 kg (1,682 lb) and measured 4.82 m (15.8 ft) long.

• Bull-headed sharks (Heterodontiformes)

These tropical, small sharks are noted for their broad head shape. The largest species is the Port Jackson shark (Heterodontus portusjacksoni) of Australasian waters, at up to 1.65 m (5.4 ft) long and weighing up to 20 kg (44 lb).

The dramatically large mouth of the basking shark, the second largest living fish.

• Mackerel sharks (Lamniformes)

Most species in this order grow quite large. The largest living species is the basking shark (Cetorhinus maximus) of the world's Northern temperate oceans, also the second largest "fish". The largest specimen, which was examined in 1851, measured 12.3 m (40 ft) long and weighed 16 metric tons (18 short tons). Perhaps the most famous "big fish", is the huge mackerel shark known as Great White Shark (Carcharodon carcharias). Specimens have been measured up to 6.4 m (21 ft) and weighing 3,312 kg (7,302 lb), with fish of at least 7 m (23 ft) long generally accepted. The Thresher Shark (Alopias vulpinus), can grow to 7.6 m (25 ft) and weigh over 510 kg (1,120 lb), but much of its length is comprised by its extreme tail. Odd and recently discovered giants also live in this order: the slender, sword-snouted Goblin Shark (Mitsukurina owstoni), with specimens of up to approximately 6.17 m (20.2 ft), and the massive Megamouth Shark (Megachasma pelagios), up to 5.6 m (18 ft) long and a weight of 1,215 kg (2,679 lb). The largest shark in the fossil record is the Megalodon (Carcharodon megalodon or Carcharocles megalodon), a Cenozoic Era relative of the great white shark. This giant shark is estimated to have reached a total length of at least 16.8 metres (55 ft). However, C. megalodon may have approached a maxima of 20.3 metres (67 ft) in total length and 103 metric tons (114 short tons) in mass. C. megalodon is also regarded as the largest macro-predatory fish ever.

The manta ray, here seen at Hin Daeng, Thailand, is the largest ray.

• Stingrays and allies (Myliobatiformes)

Both the largest species of this order and the largest of all rays is the manta ray (Manta birostris). This peaceful leviathan can reach a size of 3,000 kg (6,600 lb), a "disk" width of 9.1 m (30 ft) and a total length of 5 m (16 ft). A related species reaches barely smaller sizes, the Devil fish (Mobula mobular). It can grow up to a 5.2 m (17 ft) disk width and a total length of 6.5 m (21 ft). The largest stingray is the generally accepted to be the Short-tail stingray (Dasyatis brevicaudata), found off the southern tip of Africa and Australasia, at up to 4.3 m (14 ft) across the disk and weighing more than 350 kg (770 lb). Although there are several large stingrays that at least approach this species' size. One, the Giant freshwater stingray (Himantura chaophraya), of the large rivers of South Asia, can weigh up to 600 kg (1,300 lb).

• Catsharks & allies (Orectolobiformes)

The tremendous Whale shark is the largest species in this order. No other species in the order even approaches this size. The next largest species is the Nurse shark (Ginglymostoma cirratum), which can grow up to 4.3 m (14 ft) and weigh more than 150 kg (330 lb).

• Sawfish (Pristiniformes)

Distinguished by a long snout decorated with sharp teeth on the sides, these little known cartilaginous fishes can often reach huge sizes. The definitive largest species is not known, although the Smalltooth sawfish (Pristis pectinata) and the Green sawfish (P. zijsron), at up to reportedly 7.6 m (25 ft) and 7.3 m (24 ft), respectively, may be the largest. Weights of up to 1,955 kg (4,310 lb) have been reported, possibly for the Smalltooth species, but are not verified. The Large-tooth sawfish (P. perotteti) and Freshwater sawfish (P. microdon), both reportedly exceeding 6.5 m (21 ft) also grow very large.

• Sawsharks (Pristiophoriformes)

Despite sharing a similar appearing snout adapted in both to shred fish prey, the sawsharks are typically much smaller than sawfish. The largest sawshark is the Sixgill sawshark (Pliotrema warreni) of the South Indian ocean, which can grow up to 1.7 m (5.6 ft).

The giant guitarfish is largest species in the skate order.

• Skates and allies (Rajiformes)

The largest and most diverse order of rays' largest species is the giant guitarfish (Rhynchobatus djiddensis) of the Red Sea and the eastern Indian ocean. The top size of the species is 227 kg (500 lb) and 3.1 m (10 ft). The largest of the skates is the Common skate (Dipturus batis). This species can grow up to 2.85 m (9.4 ft) in length and weigh 97.1 kg (214 lb).

• Dogfish and allies (Squaliformes)

The largest known member of this order is the Greenland shark (Somniosus microcephalus), a giant predator of sub-Arctic waters. This species has been confirmed to as much as 6.4 m (21 ft) in length and a weight of 1,397 kg (3,080 lb), although specimens of up to 7.3 m (24 ft) have been reportedly caught. The Pacific sleeper shark (Somniosus pacificus) has been measured only to 4.4 m (14 ft) and 888 kg (1,958 lb), although larger specimens, projected to as much 7 m (23 ft) have been scientifically observed but not measured. The Spiny dogfish (Squalus acanthias), a very common species, reaches the largest sizes of the "true dogfish" family. Specimens have been measured at up to 1.6 m (5.2 ft) and 9.1 kg (20 lb).

• Angelsharks (Squatiniformes)

The largest of the bottom-dwelling angelsharks (named for their shape rather than disposition) is the Common Angelshark (Squatina squatina) of the northeast Atlantic ocean. This species can grow up to 2.44 m (8.0 ft) long and weigh more than 90 kg (200 lb).

• Electric rays (Torpediniformes)

The largest of the electric rays is Atlantic torpedo (Torpedo nobiliana). This fast-moving fish can measure 1.8 m (6 ft) long and weigh 90 kg (200 lb). However, a length of 0.6–1.5 m (2.0–4.9 ft) and weight of 30 lb (14 kg) is more typical. Females attain a larger size than males.

Armored Fishes (Placodermi)

The largest known fishes of the now-extinct class Placodermi was Dunkleosteus and Titanichthys. These particular animals may have reached lengths of 10 meters (33 ft) and are estimated to have weighed in at 3.6 tonnes (4 short tons).

Hagfish (Myxini)

The hagfish, which are not taxonomically true fish, are among the most primitive extant vertebrates. There is only one order and family in this animal class. All of the 77 known species have elongated, eel-like bodies but can immediately be distinguished by their strange downward-facing mouth, among other unique morphological features. The largest form is the Goliath hagfish (Eptatretus goliath). This species can range up to 1.28 m (4.2 ft) in length and weigh to 6.2 kg (14 lb).

Lampreys (Petromyzontida)

An invasive sea lamprey as seen feeding on an unfortunate lake trout.

As with the similarly unique hagfish, lampreys appear eel-like in shape but are unique enough to earn their own class. These creatures have cartlaginous skeletons and have been evolving separately from any other group for over 400 million years. They are predatory and often attach themselves to a fish or other small animal and gradually drain blood and organs. The largest species is the Sea lamprey (Petromyzon marinus), which can grow to 1.2 m (3.9 ft) and weigh 2.5 kg (5.5 lb).

Invertebrates

Main article: Largest invertebrates

Sponges (Porifera)

Despite its inert appearance, the heavyweight Xestospongia muta is indeed an animal

Arguably the most primitive form of animals in existence, the largest species of sponge is the giant barrel sponge, Xestospongia muta. These massively built sponges can reach 8 feet (2.4 m) in height and can be of about the same number of feet across at the thickest part of the "body". Some of these creatures have been estimated to be over 2,400 years of age.

• Calcareous sponges (Calcarea)

The largest of these small, inconspicuous sponges is probably the species Pericharax heteroraphis, attaining a height of 30 cm (1 ft). Most calcareous sponges do not exceed 10 cm (4 in) tall.

• Hexactinellid sponges (Hexactinellida)

A relatively common species, Rhabdocalyptus dawsoni, can reach a height of 1 m (3.3 ft) once they are of a very old age. This is the maximum size recorded for a hexactinellid sponge.

Cnidarians (Cnidaria)

Lion's mane jellyfish

The Lion's mane jellyfish (Cyanea capillata) is the largest cnidaria species, of the class Scyphozoa. The largest known specimen of this giant, found washed up on the shore of Massachusetts Bay in 1870, had a bell diameter of 2.5 m (8 ft), a weight of 150 kg (330 lb). The tentacles of this specimens were as long as 37 m (121 ft) and were projected to have a tentacular spread of about 75 m (246 ft) making it one of the longest extant animals.

• Corals and sea-anemones (Anthozoa)

The largest individual species are the sea-anemones of the genus Discoma, which can attain a mouth disc diameter of 60 cm (2 ft). Longer, but much less massive overall, are the anemones of the genus Ceriantharia, at up to 2 m (6.6 ft) tall. Communities of coral can be truly massive, a single colony of the Porites genus can be over 10 m (33 ft), but the actual individual organisms are quite small.

• Box jellyfish (Cubozoa)

The largest of the box jellyfish is the species Chironex fleckeri of the Australasian and South Pacific oceans, which can attain a mass of 6 kg (13 lb), a 30 cm (1 ft) bell and a tentacle length up to 2 m (6.6 ft). This species is also the most common and dangerous box jelly.

• Hydrozoans (Hydrozoa)

The colonial siphonophore Praya dubia can attain lengths of 40–50 m :(130–160 ft). The Portuguese Man O' War's (Physalia physalis) tenticles can attain a length of up to 50 m (160 ft).

Flatworms (Platyhelminthes)

A Greenhouse planarian, the largest flatworm

The largest terrestrial species of this phylum of mostly parasites, called flatworms in common language, is the Greenhouse planarian (Bipalium kewense). This planarian can reach a length of 60 cm (2 ft) and is quite massive for a flatworm.

• Monogenean flatworms (Monogenea)

The largest members of this group of very small parasites are among the genus of capsalids, Listrocephalos, reaching a length of 2 cm (0.8 in).

• Flukes (Trematoda)

The largest species of fluke is Fasciolopsis buski, which most often attacks humans and livestock. One of these flukes can be up to 7.5 cm (3 in) long and 2 cm (0.79 in) thick.

• Tapeworms (Cestoda)

The largest species of tapeworm is commonly called the fish tapeworm, Diphyllobothrium latum, since they are commonly contracted from eating fish. This devastating parasite has been recorded as reaching a length of 25 m (82 ft) in the internal organs of a human.

Roundworms (Nematoda)

The largest roundworm, Placentonema gigantissima, is a parasite found in the placentas of sperm whales which can reach up to 9 m (30 ft) in length.

Segmented worms (Annelida)

The largest of the segmented worms (commonly called earthworms) is the African giant earthworm (Microchaetus rappi). Although it averages about 1.36 m (4.5 ft) in length, this huge worm can reach a length of as much as 6.7 m (22 ft) and can be as thick as a sausage in diameter. Only the giant Gippsland earthworm, Megascolides australis, and a few giant polychaetes reach nearly comparable sizes, reaching 4 m (13 ft) and 3.6 m (11.9 ft), respectively.

Echinoderms (Echinodermata)

The largest species of echinoderm in terms of bulk is the sea star species Thromidia catalai, of the class Asteroidea, which reaches a weight of over 6 kg (13 lb). However, at a maximum span of 63 cm (25 in), it is quite a bit shorter than some other echinoderms. The longest-bodied echinoderm is the brisingid sea star Midgardia xandaros, reaching a span of 1.4 m (4.5 ft), despite being quite slender. Evastrias echinosoma is another giant echinoderm and can measure up to 1 m (3.3 ft) across and weigh 5.1 kg (11 lb).

• Crinoids (Crinoidea)

The largest species of crinoid is the unstalked feather-star (Heliometra glacialis), reaching a total width of 78 cm (31 in) and an individual arm length of 35 cm (14  in). A width of 91.4 cm (36.0 in) was claimed for one unstalked feather-star but is not confirmed. The genus Metacrinus has a stalk span of 61 cm (24 in) but, due to its bulk and multiple arms, it is heavier than Heliometra. In the past, crinoids grew much larger, and stalk lengths up to 40 m (130 ft) have been found in the fossil record.

• Sea-urchins and allies (Echinoidea)

The largest sea urchin is the species Sperosoma giganteum, which can reach a shell width of 33 cm (13 in).

• Sea-cucumbers (Holothuroidea)

The bulkiest species of sea cucumber is Stichopus variegatus, weighing several pounds, being about 21 cm (8.3 in) in diameter, and reaching a length of 1 m (3.3 ft) when fully extended. Species of sea cucumber in the genus Synapta can reach an extended length of 2 m (6.6 ft), but are extremely slender and weigh much less than Stichopus.

• Brittle stars (Ophiuroidea)

The largest known specimen of brittle star is Astrotoma agassizii. This species can grow to have a span of 1 m (3.3 ft). Sometimes, Gorgonocephalus stimpsoni is considered the largest but the maximum this species is can measure 70 cm (28 in) and a disk diameter of about 14.3 cm (5.63 in).

Ribbon worms (Nemertea)

The largest nemertean and possibly the longest animal is the bootlace worm, Lineus longissimus. A specimen found washed ashore on a beach in St. Andrews, Scotland in 1864 was recorded at a length of 55 m (180 ft).

Molluscs (Mollusca)

A 7 m (23 ft) giant squid, the second largest of all invertebrates, encased in ice in the Melbourne Aquarium.

Both the largest mollusks and the largest of all invertebrates are the largest squids. The colossal squid (Mesonychoteuthis hamiltoni) is projected to be the largest invertebrate. Current estimates put its maximum size at 12 to 14 metres (39–46 ft) long, based on analysis of smaller specimens. On February 22, 2007, authorities in New Zealand announced the capture of the largest known colossal squid specimen. It was later measured at 10 m (33 ft) long and 495 kg (1,091 lb) in weight. The mantle alone can be 5 m (16 ft) long based on a transverse slice of the pen of one specimen.

The giant squid (Architeuthis dux) was previously thought to be the largest squid, and while it is less massive and has a smaller mantle than the colossal squid, it may exceed the colossal squid in overall length including tentacles. One giant squid specimen that washed ashore in 1878 in Newfoundland reportedly measured 18 m (59 ft) in total length (from the tip of the mantle to the end of the long tentacles), 4.6 m (15 ft) in diameter at the thickest part of mantle, and weighed about 900 kg (2,000 lb). This specimen is still often cited as the largest invertebrate that has ever been examined. However, no animals approaching this size have been scientifically documented and, according to giant squid expert Dr. Steve O'Shea, such lengths were likely achieved by greatly stretching the two tentacles like elastic bands.

• Aplacophorans (Aplacophora)

The largest of these worm-like, shell-less mollusks are represented in the genus Epimenia, which can reach 30 cm (12 in) long. Most aplacophorans are less than 5 cm (2 in) long.

• Chitons (Polyplacophora)

The largest of the chitons is the gumboot chiton, Cryptochiton stelleri, which can reach a length of 33 cm (13 in) and weigh over 2 kg (4.4 lb).

The huge mouth of a mostly hidden giant clam, the largest bivalve

• Bivalves (Bivalvia)

The largest of the bivalve mollusks is the giant clam, Tridacna gigas. Although even more enormous sizes have been reported for this monstrous but passive animal, the top verified size was for a specimen from the Great Barrier Reef. This creature weighed 270 kg (600 lb), had an axial length of 1.14 m (3.7 ft) and depth of 0.75 m (2.5 ft). The largest bivalve ever was Platyceramus platinus, a Cretaceous giant that reached an axial length of up to 3 m (nearly 10 ft).

• Gastropods (Gastropoda)

The "largest" of this most diverse and successful mollusk class of slugs and snails can be defined in various ways.

The living gastropod species that has the largest (longest) shell is Syrinx aruanus with a maximum shell length of 0.91 m (3.0 ft). Also supposedly reaches a size of 16.4 kg (36 lb), a length of 70 cm (28 in) and a width of 96 cm (38 in). Another giant species is Melo amphora, which in a 1974 specimen from West Australia, measured 0.71 m (2.3 ft) long, had a maximum girth of 0.97 m (3.2 ft) and weighed 16 kg (35 lb).

The largest shell-less gastropod is the giant black sea hare (Aplysia vaccaria) at 0.99 m (3.2 ft) in length and almost 14 kg (31 lb) in weight.

The largest of the land snails is the Giant African snail (Achatina achatina) at up to 1 kg (2.2 lb) and 35 cm (14 in) long.

• Cephalopods (Cephalopoda)

(See Cephalopod size.) While generally much smaller than the giant Architeuthis and Mesonychoteuthis, the largest of the octopuses, the Giant Pacific Octopus (Enteroctopus dofleini), can grow to be very large. The largest confirmed weight of a giant octopus is 74 kg (163 lb), with a 7-metre (23 ft) arm span (with the tentacles fully extended) and a head-to-tentacle-tip length of 3.9 m (13 ft). Specimens have been reported up to 125 kg (276 lb) but are unverified.

Arthropods (Arthropoda)

In terms of overall size, the Japanese spider crab is the largest of all arthropods.

The Japanese spider crab (Macrocheira kaempferi), a crustacean of the class Malacostraca, is the largest arthropod in the world in overall size and the largest member of Brachyura (crabs). The record-sized specimen, caught in 1921, had an extended arm span of 3.8 m (12 ft) and weighed about 18.6 kg (41 lb).

However, the American lobster (Homarus americanus), another crustacean and the largest member of Astacidea (lobsters and crayfish), rivals the Japanese spider crab in mass, if not overall dimension. The largest verified lobster, also the heaviest verified arthropod, was caught in 1977 off of Nova Scotia and weighed 20.13 kg (44.4 lb) at a length of 1.07 m (3.5 ft) long. An even heavier specimen of 21.8 kg (48 lb) was caught off Chatham, Massachusetts but this weight was not confirmed.

The coconut crab (Birgus latro), also a crustacean, is the largest land arthropod and the largest land invertebrate, up to 40 cm (1.3 ft) long and weighing up to 4 kg (8.8 lb) on average. Its legs may span 1 m (3.3 ft).

The largest arthropod ever known to exist was either the eurypterid (sea scorpion) Jaekelopterus or the Carboniferous millipede Arthropleura, which were both between 2.5 and 2.6 m (8.2-8.5 ft) in length. They were closely followed by Pterygotus, an aquatic eurypterid that was up to 2.3 m (7.5 ft) in length. The closest living relatives of Eurypterida are the arachnids, horseshoe crabs, and sea spiders.

The Giant huntsman spider was considered in the December 2008 WWF report as "the world's largest Huntsman spider."

• Arachnids (Arachnida)

The largest species of arachnid by length is probably the Giant Huntsman spider (Heteropoda maxima) of Laos, which in 2008 replaced the Goliath birdeater (Theraphosa blondi) of Northern South America as the longest-known spider. However the most massive arachnids, of comparable dimensions and possibly even greater mass, are the Chaco golden knee, Grammostola pulchripes, and the Brazilian salmon pink, Lasiodora parahybana. The Huntsman spider may span up to 29 cm (11 in) (larger than a dinner plate) across the legs, while in the New World "tarantulas" like Theraphosa it can range up to 26 cm (10 in). In Grammostola, Theraphosa and Lasiodora, the weight is projected to be up to at least 150 g (5.3 oz) and body length is up to 10 cm (3.9 in). The largest of the scorpions is the species Heterometrus swammerdami of the Indian subcontinent, which have a maximum length of 29.2 cm (11.5 in). Another extremely large scorpion is the African Imperial scorpion (Pandinus imperator), which can weigh 57 g (2.0 oz) but is not known to exceed a length of 23 cm (9.1 in). However, they were dwarfed by Pulmonoscorpius kirktonensis, a giant extinct species of scorpion from Scotland, at an estimated length of 0.7 m (2.3 ft) and the aquatic Brontoscorpio, at up to 1 m (3.3 ft).

• Branchiopods (Branchiopoda)

The largest of these primarily freshwater crustaceans is probably Branchinecta gigas, which can reach a length 10 cm (3.9 in).

A specimen of Scolopendra gigantea, which can exceed a foot in length

• Centipedes (Chilopoda)

The biggest of the centipedes is Scolopendra gigantea of the neotropics, reaching a relatively enormous length of 33 cm (13 in).

• Millipedes (Diplopoda)

Two species of millipede both reach a very large size Archispirostreptus gigas of East Africa and Scaphistostreptus seychellarum, endemic to the Seychelles islands. Both of these species can slightly exceed a length of 28 cm (11 in) and measure over 2 cm (0.79 in) in diameter. The 300-million year old Arthropleura, either a primitive millipede or a close relative, was the largest land invertebrate ever, having measured at least 2.5 m (8.2 ft) long and 45 cm (18 in) wide.

• Barnacles and allies (Maxillopoda)

The largest species is a copepod (Pennella balaenopterae), known exclusively as a parasite from the backs of Fin Whales (Balaenoptera physalus). The maximum size attained is 32 cm (about 13 in). The largest of the barnacles is the giant acorn barnacle, Balanus nubilis, reaching 7 cm (2.8 in) in diameter and 12.7 cm (5 in) high.

• Horseshoe crabs (Merostomata)

The four modern horseshoe crabs are of roughly the same sizes, at up to 60 cm (2 ft) in length. Easily the best known species is Limulus polyphemus of North America.

• Ostracods (Ostracoda)

The largest living representative of these small and little-known but numerous crustaceans is the species Gigantocypris australis females of which reaching a maximum length of 3 cm (1.3 in).

The strange, deep-sea species known as the giant isopod

• Amphipods, Isopods, and allies (Peracarida)

The largest species is the giant isopod (Bathynomus pergiganteus), which can reach a length of 45 cm (18 inches) and a weight of 1.7 kg (3.7 lb).

• Sea spiders (Pycnogonida)

The largest of the sea spiders is the deep-sea species Colossendeis colossea, attaining a leg span of nearly 60 cm (2 ft).

• Remipedes (Remipedia)

The largest of these cave-dwelling crustaceans is the species Godzillius robustus, at up to 4.5 cm (1.8 in).

• Trilobites (Trilobita)

Some of these extinct marine arthropods exceeded 60 cm (24 inches) in length. A nearly complete specimen of Isotelus rex from Manitoba attained a length over 70 cm (27 in), and a Ogyginus forteyi from Portugal was almost as long. Fragments of trilobites suggest even larger record sizes. An isolated pygidium of Hungioides bohemicus implies that the full animal was 90 cm (36 in) long.

Insects (Insecta)

The goliath beetle is arguably the world's heaviest insect

Insects, which are a type of arthropod, are easily the most numerous group of organisms on the planet, with over million species identified so far and many more believed to be undescribed. The title of heaviest insect in the world has many rivals, although the beetles, in addition to being the most species-rich order of organisms, almost certainly include the largest species. Although heavyweight giant wetas (Deinacrida heteracantha) are known, the elephant beetles of Central and South America, (Megasoma elephas) and (M. actaeon), the Titan beetle (Titanus giganteus) of the neotropical rainforests or the goliath beetles, (Goliathus goliatus) and (G. regius), of Africa's rainforests are believed to reach a higher weight. The most frequently crowned are the goliath beetles the top known size of which is at least 100 g (3.5 oz) and 11.5 cm (4.5 in). The elephant beetles and titan beetle can reach greater lengths than the goliath, at up to 13.1 cm (5.2 in) and 15.2 cm (6.0 in), respectively, but this is in part thanks to their rather large horns. The goliath beetle's wingspan can range up to 25 cm (9.8 in).

The longest insects are the stick insects, see below.

Representatives of the extinct dragonfly-like order Protodonata such as the Carboniferous Meganeura monyi of what is now France and the Permian Meganeuropsis permiana of what is now North America are the largest insect species ever known. These creatures had a wingspan of some 75 cm (30 in) and a body weight of over 1 lb (450 g), making them about the size of a crow.

The massive giant burrowing cockroach is the world's largest cockroach

• Cockroaches and termites (Blattodea)

The largest cockroach is the Australian giant burrowing cockroach (Macropanesthia rhinoceros). This species can attain a length of 8.3 cm (3.3 in) and a weight of 36 g (1.3 oz). The giant cockroach (Blaberus giganteus) of the neotropics reaches comparable lengths although is not as massive as the burrowing species. The termites, traditionally classified in their own order (Isoptera), have recently been re-considered to belong in Blattodea. The largest of the termites is the African species Macrotermes bellicosus. The queen of this species can attain a length of 14 cm (5.5 in) and breadth of 5.5 cm (2.2 in) across the abdomen; other adults, on the other hand, are about a third of the size.

• Beetles (Coleoptera)

The beetles are the largest order of organisms on earth, with about 400,000 species so far identified. The most massive species are the Goliathus, Megasoma and Titanus beetles already mentioned. Another fairly large species is the Hercules beetle (Dynastes hercules) of the neotropic rainforests with a maximum overall length of at least 19 cm (7.5 in) including the extremely long pronotal horn. The weight in this species does not exceed 16.5 g (0.58 oz). The longest overall beetle is Longhorn beetle (Batocera wallacei) of New Guinea, which can attain a length of 26.6 cm (10.5 in), about 19 cm (7.5 in) of which is comprised by the long antennae.

• Earwigs (Dermaptera)

The largest of the earwigs is the Saint Helena giant earwig (Labidura herculeana), endemic to the island of its name, which is up to 8 cm (3.1 in) in length.

Dwarfing a housefly, the species Gauromydas heros is the world's largest fly

• True flies (Diptera)

The largest species of this huge order, which includes the common housefly, is the neotropical species Gauromydas heros, which can reach a length of 6 cm (2½ in) and a wingspan of 10 cm (4 in). Species of crane fly, the largest of which is Holorusia brobdignagius, can attain a length of 23 cm (9 in) but are extremely slender and much lighter in weight than Gauromydas.

• Mayflies (Ephemeroptera)

The largest mayflies are members of the genus Proboscidoplocia from Madagascar. These insects can reach a length of 7 cm (2.8 in).

A giant water bug as seen walking over land

• True bugs (Hemiptera)

The largest species of this diverse, huge order is usually listed as the giant water bug (Lethocerus maximus) of the West Indies and neotropics. This species can attain a length of 11.6 cm (4.6 in), although it is more slender and less heavy than most other insects of this size (principally the huge beetles). Challenging or surpassing this size, the cicada Pomponia imperatoria which can reportedly grow to 15 cm (5.9 in) in length. The cicadas of the genus Tacua can also grow to comparably large sizes. The largest type of aphid is the Giant oak aphid (Stomaphis quercus), which can reach an overall length of 2 cm (0.79 in). The biggest species of leafhopper is Ledromorpha planirostris, which can reach a length of 2.8 cm (1.1 in).

Megachile pluto is the largest species of bee

• Ants and allies (Hymenoptera)

The largest of the ants, and the heaviest species of the order, are the females of the African Dorylus helvolus, reaching a length of 5.1 cm (2.0 in). The ant that averages the largest for the mean size of the whole colony is Ponerine Ant (Dinoponera gigantea) of South America, averaging up to 3.3 cm (1.3 in) from the mandibles to the end of abdomen. Workers of the Bulldog Ant (Mymecia brevinoda) of Australia are up to 3.7 cm (1.5 in) in total length, although much of this is from their extremely large mandibles. The largest of the bee species, also in the order Hymenoptera, is Megachile pluto of Indonesia, the females of which can be 3.8 cm (1.5 in) long, with a 6.3 cm (2.5 in) wingspan. Nearly as large, the carpenter bees can range up to 2.53 cm (1.00 in). The largest wasp is probably the so-called tarantula hawk species Pepsis pulszkyi of South America, at up to 6.8 cm (2.7 in) long and 11.6 cm (4.6 in) wingspan, although many other Pepsis approach a similar size.

The Queen Alexandra's birdwing is the largest species of butterfly.

• Moths and allies (Lepidoptera)

The largest species overall is probably either the Queen Alexandra's birdwing (Ornithoptera alexandrae), a butterfly from Papua New Guinea, or the Atlas moth (Attacus atlas), a moth from Southeast Asia. Both of these species can reach a length of 8 cm (3.1 in), a wingspan of 28 cm (11 in) and a weight of 12 g (0.42 oz). One Atlas moth allegedly had a wingspan of 30 cm (12 in) but this measurement was not verified. The larvae in the previous species can weigh up to 58 g (2.0 oz) and 54 g (1.9 oz), respectively. However, the White Witch (Thysania agrippina) of Central and South America, has the longest recorded wingspan of the order, and indeed of any living insect,, though it is exceeded in surface area and mass by both Ornithoptera and Attacus. The verified record-sized Thysania spanned 30.8 cm (12.1 in) across the wings, although specimens have been reported to 36 cm (14 in). This challenged by the Hercules moth (Coscinocera hercules) of New Guinea and Northern Australia, which is confirmed to 28 cm (11 in) while unconfirmed specimens have spanned up to 35.5 cm (14.0 in). The heaviest mature moths have been cited in the Giant carpenter moth (Xyleutes boisduvali) of Australia, which has weighed up to 20 g (0.71 oz) although the species doesn't surpass 25.5 cm (10.0 in) in wingspan.

• Praying mantises (Mantodea)

The largest species of this order is Toxodera denticulata from Java, which has been measured up to 20 cm (7.9 in) in overall length. However, an undescribed species from the Cameroon jungle is allegedly much larger than any other mantis and may rival the larger stick insects for the longest living insect. Among widespread mantis species, the largest is the Chinese mantis (Tenodera aridifolia). The females of this species can attain a length of up to 10.6 cm (4.2 in).

• Alderflies and allies (Megaloptera)

This relatively small insect order includes some rather large species, many of which are noticeable for their elongated, imposing mandibles. The dobsonflies reach the greatest sizes of the order and can range up to 12.5 cm (4.9 in) in length.

The Blue eyes lacewing is one of the largest net-winged insects

• Net-winged insects (Neuroptera)

These flying insects reach their largest size in Palparellus voeltzkowi, which can have a wingspan over 16 cm (6.3 in). The largest lacewing is the Blue eyes lacewing (Nymphes myrmeleonides) of Australia, which can measure up to 4 cm (1.6 in) in length and span 11 cm (4.3 in) across the wings. Some forms of this ancient order could grow extremely large during the Jurassic Era and may have ranked among the largest insects ever.

• Dragonflies (Odonata)

The largest living species of dragonfly is Megaloprepus caerulatus of the neotropics, attaining a size of as much as 19 cm (7.5 in) across the wings and a body length of over 12 cm (4.7 in). Spanning up to 17.6 cm (6.9 in) and measuring up to 11.8 cm (4.6 in) long, Tetracanthagyna plagiata of Southeast Asia is bulkier and heavier than Megaloprepus. The largest species of dragonfly ever is the extinct aforementioned Meganeura, although it is not certain to be included in the modern dragonfly order.

A giant weta displays its large, bulky appearance

• Grasshoppers and allies (Orthoptera)

The largest of this widespread, varied complex of insects are the giant wetas of New Zealand, which is now split among 12 species. The largest of these is the Little Barrier Island Giant Weta (Deinacrida heteracantha), the largest specimen was weighed at 71.3 g (2.52 oz), one of the largest insects weights ever known. These heavyweight insects can be over 9 cm (3.5 in) long. The largest grasshopper species is often considered to be the Australian Giant Grasshopper (Valanga irregularis), which ranges up to 9 cm (3.5 in) in length. The American Eastern Lubber Grasshopper (Romalea guttata) can allegedly range up to 10 cm (3.9 in) in length. However, the greatest grasshopper sizes known, to 12 cm (4.7 in), have been cited in the South American Giant Grasshopper (Tropidacris violaceus). The longest members of this order (although much less heavier than the giant wetas) is the katydid Macrolyristes corporalis of Southeast Asia which can range up to 21.5 cm (8.5 in) with its long legs extended and can have a wingspan of 20 cm (7.9 in).

Phobaeticus serratipes, the world's second longest insect, employs remarkable camouflage

• Stick insects (Phasmatodea)

The longest known stick insect, and indeed the longest insect ever known, is Phobaeticus chani of the Bornean rainforests, with one specimen held in the Natural History Museum in London measuring 56.7 cm (22.3 in) in total length. This measurement is, however, with the front legs fully extended. The body alone still measures 35.7 cm (14.1 in). The species with the second longest body is Phobaeticus kirbyi, also of Borneo, which measures up to 32.8 cm (12.9 in), while the overall length (from the hind to the front legs) is up to 54.6 cm (21.5 in). The second longest insect in terms of total length is Phobaeticus serratipes of Malaysia and Singapore, measuring up to 55.5 cm (21.9 in). Another extremely long stick insect is Pharnacia maxima, which measured 51 cm (20 in) with its legs extended. The Spiny Stick Insect (Heteropteryx dilatata) of Malaysia does not reach the extreme lengths of its cousins, the body reaching up to 16 cm (6.3 in) long, but it is much bulkier. The largest Heteropteryx weighed about 65 g (2.3 oz) and was 3.5 cm (1.4 in) wide across the thickest part of the body.

• Louse (Phthiraptera)

These insects, famous (or rather infamous) for their habit of living parasitically on other animals, are as a rule quite small. The largest known variety is Haematopinus suis, a "sucking lice" species that favors large livestock like pigs and cattle. It can range up to 6 mm (0.24 in) in length.

A favorite with fisherman and the world's largest stonefly: Pteronarcys californica

• Stoneflies (Plecoptera)

The largest species of stonefly is Pteronarcys californica of western North America, a species favored by fishermen as lures. This species can attain a length of 5 cm (2.0 in) and a wingspan of over 9.5 cm (3.7 in).

• Booklice (Psocoptera)

The largest of this order of very small insects are the barklouse of the genus Psocus, the top size of which is about 1 cm (0.39 in).

• Fleas (Siphonaptera)

The largest species of flea is Hystrichopsylla schefferi. This parasite is known exclusively from the fur of the Mountain Beaver (Aplodontia rufa) and can reach a length of 1.2 cm (0.5 in).

• Silverfishes and allies (Thysanura)

These strange-looking insects, known to feed on human household objects, can range up to 4.3 cm (1.7 in) in length. A 350 million year old form was known to grow quite large, at up to 6 cm (2.4 in).

• Thrips (Thysanoptera)

Members of the genus Phasmothrips are the largest kinds of thrips. The maximum size these species attain is approximately 1.3 cm (0.5 in) in length.

• Caddisflies (Trichoptera)

The largest of the small, moth-like caddisflies is Eubasilissa maclachlani. This species can range up to 7 cm (2.8 in) across the wings.

Plants

Ceroxylon quindiuense (Quindío wax palm) is the tallest monocot in the world

• Flowering plants (angiosperms)

This is the most diverse and numerous division of plants, with upwards of 400,000 species.

The largest known flowering plant, and indeed largest plant and organism, is a grove of male Aspen in Utah, nicknamed Pando (Populus tremuloides). The grove is connected by a single root system, and each stem above the ground is genetically identical. It is estimated to weigh approximately 6,000,000 kg, and covers 0.43 km² (106 acres).

Another form of flowering plant that rivals Pando as the largest organism on earth in breadth, if not mass, is the giant marine plant, Posidonia oceanica, discovered in the Mediterranean near the Balearic Islands, Spain. Its length is about 8 km (4.3 mi). Although this plant has not been proven to be a single connected organism, all the samples do have the same DNA. It may also be the oldest living organism in the world, with an estimated age of 100,000 years.

Rafflesia arnoldii flower

The tallest flowering plant is thought to be Eucalyptus regnans, which can reach heights of 99.6 m (327 ft).

Other records among flowering plants include, the title of largest flower, which belongs to the species Rafflesia arnoldii. One of these flowers can reach a diameter of 1 m (3.3 ft) and weigh up to 11 kg (24 lb). The largest unbranched inflorescence, resembling (but not qualifying as) a giant flower, belongs to the Titan Arum (Amorphophallus titanum), reaching almost 3 m (9.8 ft) in height. The absolute largest inflorescence, at up to 8 m (26.5 ft) long, is borne by the Talipot palm (Corypha umbraculifera) of India.

General Sherman tree, in Sequoia National Park

• Conifers (Pinopsida)

The conifer division of plants include the tallest organism, and the largest single-stemmed plants by volume, mass, and circumference. The largest by volume and mass is the Giant Sequoia (Sequoiadendron giganteum), native to Sierra Nevada, California; it grows to an average height of 70–85 m (230–280 ft) and 5–7 m (16–23 ft) in diameter. Specimens have been recorded up to 94.9 m (307 ft) in height and (not the same individual) 8.98 m (29 ft) in diameter; the largest individual still standing is the General Sherman tree, with a volume of 1,489 m³ (52,600 ft³). The largest specimen on record is the Lindsey Creek tree, felled in 1905 during a storm. Although not so large in volume, the closely related Coast Redwood (Sequoia sempervirens) of the Pacific Northwest in North America is taller, reaching a maximum height of 115.55 m (379.1 ft) - the Hyperion Tree), which ranks it as the world's tallest known living tree and organism (not including its roots under ground). The conifers also include the largest tree by circumference in the world, the Montezuma Cypress (Taxodium mucronatum). The thickest recorded tree, found in Mexico, is called Árbol del Tule, with a circumference of 57.9 m (190 ft) at its base and a diameter of 14.5 m (48 ft) at 1.5 m (5 ft) above ground level; its height is over 39.4 m (129 ft). These trees dwarf any other non-communal organism, as even the largest Blue Whales are likely to weigh one-sixteenth as much as a large Giant Sequoia or Coast Redwood. See record trees for other tree records.

• Cycads (Cycadophyta)

The largest species of cycad is Hope's Cycad (Lepidozamia hopei), of the Queensland area of Australia. The largest examples of this species have been over 15 m (49 ft) tall and have had a circumference of 1.5 m (4.9 ft).

• Liverworts (Marchantiophyta)

The largest species of liverwort is a New Zealand species, Schistochila appendiculata. The top size of this species is 1.1 m (3.6 ft) long, a diameter of 2.5 cm (1 in) and a stem length of 10 cm (4 in).

• Mosses (Bryophyta)

The world's tallest moss is Dawsonia superba, of New Zealand. This species can be 50 cm (20 in) tall.

Pteridophyta

A stand of Equisetum myriochaetum, the world's largest horsetail species

• Horsetails (Equisetopsida)

The largest of horsetail is the species Equisetum myriochaetum, of central Mexico. The biggest specimen known was 8 m (26.4 ft) tall and had a diameter of 2.5 cm (1 in).

• Ferns (Pteridopsida)

The largest species of fern is probably Cyathea brownii of Norfolk Island, which may be 20 m (66 ft) or more in height.

Chromists

• Brown algae (Phaeophyceae)

The largest form of algae is the huge form of seaweed from the northwestern Pacific known as the giant kelp (Macrocystis pyrifera). The record-sized stem from one of these just slightly exceeded 53 m (174 ft).

Fungi

Armillaria ostoyae

The largest living fungus may be a honey fungus of the species Armillaria ostoyae. A mushroom of this type in the Malheur National Forest in the Blue Mountains of eastern Oregon, U.S. was found to be the largest fungal colony in the world, spanning 8.9 km² (2,200 acres) of area. This organism is estimated to be 2400 years old. The fungus was written about in the April 2003 issue of the Canadian Journal of Forest Research. While an accurate estimate has not been made, the total mass of the colony may be as much as 605 tons. If this colony is considered a single organism, then it is the largest known organism in the world by area, and rivals the aspen grove "Pando" as the known organism with the highest living biomass. It is not known, however, whether it is a single organism with all parts of the mycelium connected.

In Armillaria ostoyae each individual mushroom (the fruiting body, similar to a flower on a plant) has only a 5 cm (2 inch) stipe, and a pileus up to 12.5 cm (5 in) across. There are many other fungi which produce a larger individual size mushroom. The largest known fruiting body of a fungus is a specimen of Fomitiporia ellipsoidea found on Hainan Island. The fruiting body weighs between 400 and 500 kg.

Until, Fomitiporia replaced it, the largest individual mushroom was Rigidoporus ulmarius. Rigidoporus is up to 284 kg (626 lb), 1.66 m (5.4 ft) tall, 1.46 m (4.8 ft) across the head of the mushroom, and has a circumference of 4.9 m (16 ft).

Protists

• Amoebozoans

Among the organisms that are not multicellular, the largest are the slime moulds, such as Physarum polycephalum, some of which can cover an area of more than 1,000 cm² (1 sq ft).

• Euglenozoans

Some euglenophytes, such as certain species of Euglena, reach lengths of 400 μm.

• Rhizarians

The largest species traditionally considered protozoa are giant amoeboids like foraminiferans. One such species, the xenophyophore Syringammina fragilissima, can attain a size of 20 cm (8 in).

• Alveolates

The largest ciliates, such as Spirostomum, can attain a length over 3 mm (0.12 in).

• Stramenopiles

Macrocystis pyrifera, the largest species of giant kelp

The largest stramenopiles are the giant kelps, Macrocystis pyrifera, which can grow to a height of over 45 m (150 ft).

Bacteria

A microscopic view of Thiomargarita namibiensis, a rare bacteria visible to the naked eye

The largest known species of bacterium is Thiomargarita namibiensis, which grows to 0.75 mm (0.03 in) in diameter, making it visible to the naked eye and up to a million times the size of more typical bacteria.

• Cyanobacteria

One of the largest "blue green algae" is Lyngbya, whose filamentous cells can be 50 μm wide.

Viruses

The largest known virus is the Megavirus (the Megavirus chilensis megavirus), with a capsid of 440 nm in diameter (icosahedral capsid), 1,259,197 genome length and 1120 genes.

See also

• Smallest organisms
• Island gigantism
• Deep-sea gigantism
• Giant animal
• Largest body part
• Charismatic megafauna
• Largest prehistoric animals
• Megafauna
• List of long-living organisms
• Genome size
• Superorganism
• Largest mammals
• Largest reptiles
• Largest birds
• Largest amphibians
• Largest invertebrates