Information about Largest Organism

The largest organism found on earth can be measured using a variety of methods. It could be defined as the largest by volume, mass, height, or length. Some creatures group together to form a superorganism, though this cannot truly be classed as one large organism. (The Great Barrier Reef, the world's largest coral reef (stretching 2,000 km) has been shown to be a collection of many organisms and is the largest known superorganism, though Gaia theory would consider the whole of the biosphere as a sort of superorganism.)

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^[4] organism in the world, by mass or volume.^[5] It covers 43 hectares (.43 km²) and is estimated to weigh 6,600 tons. ^[6]

A giant fungus of the species Armillaria ostoyae in the Malheur National Forest in Oregon was found to span 8.9 km² (2,200 acres)^[1], 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 ^[2], but unless its mycelium is 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 Sea near the Balearic Islands. It is about 8 km (4.3 miles) in length.

Excluding multi-stem trees, the General Sherman tree, an individual Giant Sequoia with a volume of 1487 m³, would hold the title of the world's largest living organism, if measured in volume and mass.^[3] This tree stands 83.8 m (274 ft 11 in) tall and the trunk alone is estimated to weigh over 2000 tons. The largest single-stem tree ever measured was the “Lindsey Creek Tree,” a coastal redwood with a minimum trunk volume of over 2500 m³ and a mass of over 3600 tons, which fell over during a storm in 1905.^[7]

By volume and weight, the largest known animal ever to have lived is the blue whale, an endangered species whose official record length is 33.58 m (110 ft 2 inches), and weight 210 tons (for a pregnant female). The largest land animals today are male Savannah Elephants, with one known example weighing around 12,272 kg (27,000 lb), though many extinct species, such as many dinosaurs, were much larger.

Vertebrates

Mammals (Mammalia)

A member of the order Cetacea, the Blue whale (Balaenoptera musculus) is believed to be the largest animal ever to have lived. The maximum recorded weight was 190 tonnes and 30 m (100 ft) long, while longer ones, up to 33.3 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. At birth it is common for an elephant calf to weigh 100 kg (225 pounds). The largest elephant ever recorded was shot in Angola in 1974. It was a male and weighed 12,272 kg or 13.5 tons (27,000 lb), with an overall length (trunk to tail) of 10.6 m (35 ft) and a shoulder height of 4.2 m (13.7 ft).

• Monotreme mammals (Monotremata). The largest extant monotreme is the Western Long-beaked Echidna weighing up to 16.5 kg (36.4 lb) and measuring 1 m (3.3 ft) long. The largest monotreme (egg-bearing mammal) 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).
• Marsupials (Marsupialia). The Red Kangaroo (Macropus rufus) is the largest living marsupial. The maximum size of these lanky mammals is 100 kg (220 lb) and 1.92 m (6.3 ft) tall. Many much larger marsupials existed prehistorically, the largest of which was Diprotodon. This rhino-sized herbivore would have easily exceed 2 tonnes (4,400 lb), 3.3 m (11 ft) in length and 1.83 m (6 ft) in height.
• Non-Paenungulate Afrotherians (Afroinsectiphilia). The largest species of this clade (which also contains elephant shrews, tenrecs and golden moles) is the Aardvark. Aardvarks are typically up to 1.3 meters in length with a weight of up to 65 kg, although some larger exceptions can be found.

• Even-toed Ungulates (Artiodactyla). The largest species in terms of weight is the Hippopotamus (Hippopotamus amphibius), reaching 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), and despite being relatively slender, reaching a top weight of 2 tonnes (2.2 tons).
• Carnivores (Carnivora). The largest species is now, with the inclusion of pinnipeds, the Southern Elephant Seal (Mirounga leonina). The top size recorded for this species was 5,000 kg (11,000 lb) and 6.9 m (22.5 feet) long. The largest living land carnivores are the Polar Bear (Ursus maritimus) and the Brown Bear (Ursus arctos), both exceptionally exceeding 1 tonne (2,205 lb), 3 m (10 ft) long, and 1.5 m (5 ft) tall at the shoulder.
• Whales (Cetacea). The largest whale and animal is the aforementioned blue whale, a baleen whale (Mysticeti). The largest toothed whale (Odontoceti) is the Sperm Whale, bulls of which range usually range up to 18 metres (59.5 ft) and a mass of 50 tonnes (55 tons), but may possibly grow considerably larger. The Orca or Killer Whale (Orcinus orca) is the largest species of the oceanic dolphin family (Delphinidae). Males normally grow from 6.5-8 m long (20-25 ft) and weigh in excess of 6 tonnes; it has been reported that especially large males have reached nearer 8 tonnes. Females are smaller, growing from 5.7-7m (18-22 ft) and a weight of about 5 tonnes. The longest Orca ever recorded was a male off the coast of Japan, measuring 9.8 m (32 ft).
• Bats (Chiroptera). The largest bat species is the Giant golden-crowned flying fox (Acerodon jubatus), a rare fruit bat and endangered species 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 (6 ft). The Ghost Bat (Macroderma gigas) 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). The top size for this species is 60 kg (132 lb) and 1.5 m (5 ft) in length. Much larger prehistoric examples are known, especially Glyptodon, which easily topped 2.7 m (9 ft) and 2 tonnes (4,400 lb).
• 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).
• Hedgehogs, Gymnures, Shrews, and Moles (Erinaceomorpha & Soricomorpha). The largest of these two orders of small mammals is the Greater Moonrat (Echinosorex gymnura), the maximum size of which is over 2 kg (4.4 lb) and 60 cm (24 in).
• 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.
• Rabbits, Hares, & Pikas (Lagomorpha). The largest species is the European Hare (Lepus europaeus), which is up to 6.6 kg (14.6 lb) and 76 cm (30 in) long.
• Odd-toed Ungulates (Perissodactyla). The largest extant species is the White Rhinoceros (Ceratotherium simum). The largest size this species can attain is 4,540 kg (10,000 lb), 4.7 m (15.5 ft) long, and 2 m (6.6 ft) tall. It is slightly larger than the Indian Rhinoceros. The largest land mammal ever was Indricotherium, a member of this order. It stood up to 5.5 m (18 ft) tall, measured over 9 m (30 ft) long and weighed up to 20 tonnes (22 tons).
• Pangolins (Pholiodata). 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).
• Anteaters & Sloths (Pilosa). The largest species is easily the Giant Anteater (Myrmecophaga tridactyla). A large adult can weigh as much as 65 kg (143 lb) and measure 2.4 m (8 ft) in overall length. The sloths attained much larger sizes prehistorically, the largest of which were Megatherium which, at an estimated average weight of 4.5 tonnes (5 tons) and height of 5.1 m (17 ft), was about the same size as the African Bush Elephant.

• Primates (Primates). The Eastern Lowland Gorilla (Gorilla beringei graueri) is the largest living primate. The maximum size of a male gorilla can be over 225 kg (500 lb) and 1.83 m (6 ft) in the wild, with much heavier weights 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 around 5 million years ago until about 100 thousand years ago in the region of India and China. Human beings (Homo sapiens) can attain massive weights measured in thousands of pounds (up to 1,600 lb), but these are cases of morbid obesity, tumor, and other medical malady, and enormous heights (up to 8 ft 11.1 in), due to the growth disorder gigantism. The tallest humans (who have reached heights of at least 7 ft 8 in even when not afflicted with gigantism) are the tallest living primates.
• Elephants, mammoths, and mastodons (Proboscidea). Contrary to popular belief, extinct species in the order Proboscidea, such as mammoths and mastodons, did not dwarf the modern African Bush Elephant. The largest elephant ever was probably the Imperial Mammoth (Mammuthus imperator), which were believed to have attained a size of as much as 4.5 m (15 ft) tall and weighed over 13.6 tonnes (15 tons).
• Rodents (Rodentia). The largest living rodent is the capybara, native to most of the tropical and temperate parts of South America east of the Andes, always near water. Full-grown capybaras can reach a top size of 80 kg (176 lb), 1.5 m (5 ft) long and 90 cm (3 ft) tall. The largest known rodent ever is Phoberomys insolita, an extinct species known only from fossils. An almost complete skeleton of its slightly smaller Late Miocene relative Phoberomys pattersoni was discovered in Venezuela in 2000; it was 3 m (10 ft) long, with an additional 1.5 m (5-foot) tail, and probably weighed around 700 kg (1,540 lb).
• Tree Shrews (Scadentia). 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).
• Dugongs and manatees (Sirenia). The largest living species in the order Sirenia of dugongs and manatees is the West Indian Manatee (Trichechus manatus). The maximum 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) was much larger, growing up to at least 7.9 m (26 ft) long and weighing up to 11 tonnes (12.1 tons).

Reptiles (Reptilia)

The largest living reptile, a representative of the order Crocodilia, is the saltwater crocodile (Crocodylus porosus), with adult males being typically 4.5 to 5 m (14.8 to 16.5 ft) long. The largest confirmed saltwater crocodile on record was 20.6 feet (6.3 meters) long, and weighed over 1,900 kg (4,100 lbs).^[8] Unconfirmed reports of much larger crocodiles exist, but examinations of incomplete remains have never suggested a length greater than 23 feet (7 meters).[1]

Extinct crocodilians were sometimes much larger, such as Deinosuchus, at up to 12 m (40 ft) and 9.1 tonnes (10 tons), Sarcosuchus imperator, also at up to 12 m (40 ft) and 13.6 tonnes (15 tons), and Rhamphosuchus, possibly up to 18 m (60 ft) long.

• Lizards & snakes (Squamata). The most massive member of this reptilian superorder is the Green Anaconda (Eunectes murinus). The maximum verified size is 9.5 m (31.4 ft) and 250 kg (550 lb), although much larger anacondas have been reported. Even longer, the Reticulated Python (Python reticulatus), can be up to 10 m (33 ft), but is more slender than the anaconda. The largest of the living lizards is the Komodo Dragon (Varanus komodoensis). The largest-ever member of the order was probably one of the giant mosasaurs, such as Hainosaurus, Mosasaurus, or Tylosaurus, all of which grew to around 15 m (50 ft). Some prehistoric snakes such as Gigantophis and Madtsoia are thought to have reached sizes analogous or even superior to those of anacondas and pythons. However, the fossil remains of these snakes are too incomplete to know for sure the size they attained. The largest terrestrial squamate ever, Megalania, could have possibly weighed as much as 2.7 tonnes (3 tons) and measured up to 7 m (23 ft) long.
• Tuataras (Sphenodontia). The larger of the two extant species of tuatara is the Brothers Island Tuatara (Sphenodon guntheri). The maximum size is 1.4 kg (3.1 lb) and 76 cm (30 in).
• Turtles (Testudines). The largest living turtle is the Leatherback Sea Turtle (Dermochelys coriacea), reaching a maximum size of nearly 2.7 m (9 ft) and a weight of 932 kg (2050 lb). There are many extinct turtles that vie for the title of the largest ever. The largest seems to be Archelon ischyros, which reached a size of 4.84 m (16 ft) and a weight of 5.1 tonnes (5.7 tons).
• Pterosaurs (Pterosauria); now extinct. A dinosaur-era reptile (although not technically a dinosaur) is believed to have been the largest flying animal that ever existed: the pterosaur Quetzalcoatlus northropi. The maximum size of this soaring giant was believed to have been about 127 kg (280 lb) and 12 m (40 ft) across the wings. Some incomplete remains, however, demonstrate the existence of larger pterosaurs, with some estimates suggesting a maximum wingspan of 18 meters.

• Dinosaurs (Dinosauria); now extinct, except for Theropod descendants, the Aves.

All of the largest dinosaurs, and the largest animals to ever live on land, were plant-eating sauropods. The tallest and heaviest sauropod known from a complete skeleton is the Brachiosaurus 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 tons). The longest is the 27 m (89 ft) long Diplodocus which was discovered in Wyoming, and mounted in Pittsburgh's Carnegie Natural History Museum in 1907.

There may have been larger sauropods, but they are known from only a small handful of bones. The current record holders all date from the 1970s or later, and include the massive Argentinosaurus, which may have weighed 80,000 – 100,000 kg (90 to 110 tons); the longest, the 40 m (130 ft) long Supersaurus; and the tallest, the 18 m (60 ft) Sauroposeidon, which could have reached into a 6th-floor window. Seismosaurus was once thought to have measured around 50 m (170 ft) in length, making it the longest known vertebrate, but more recent reconstructions have dropped this figure significantly — down to 40 m (130 ft).

Less well described finds may even exceed this. Bruhathkayosaurus may have weighed as much as a blue whale and have been considerably longer, and the almost mythical Amphicoelias fragillimus would have been longer still, but Bruhathkayosaurus is based on very poor material, and the only fossil of Amphicoelias was destroyed soon after discovery.

*Theropods (Theropoda). The longest and heaviest theropod was the Spinosaurus, at 15 to 17.4 metres (49.2 to 57.1 feet) in length and a weight of up to 9 tons.^[9] 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.

*Armored Dinosaurs (Thyreophora). The largest of the Thyreophorans was Ankylosaurus,
which may have measured up to 9 meters in length.

*Cerapods (Cerapoda). The largest Cerapod was the Ceratopsian, Triceratops.
Triceratops are estimated to have reached about 8 m (26 ft) in length^[10] and weighed 6.1 tonnes (13,400 lb).^[11]

Birds (Aves)

The largest living bird, as well as the largest member of the Struthioniformes, is the ostrich (Struthio camelus) reaching a height of over 2.7 m (9 ft) and weighing over 156 kg (345 lb).^[12] Eggs laid by the Ostrich can weigh 1.4 kg (3 lb) and are the largest eggs in the world today (and are also the largest single cell of any organism, although the sea algae Caulerpa could be considered the largest active cell).

The largest bird in the fossil record may be the extinct Elephant Birds of Madagascar, which were related to the Ostrich. They exceeded 3 m (10 ft) and 500 kg (1,120 lb). The last of the Elephant Birds became extinct about 300 years ago. Of almost the exact same 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 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^[12] when it was erected in an unnatural position, but weighed about half as much as a large Elephant Bird or mihirung due to its comparatively slender frame. The largest carnivorous bird was the phorusrhacid 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 (9.2 ft).

The largest bird ever capable of flight was Argentavis magnificens, a now extinct member of the Teratornithidae group, with a wingspan of up to 8.3 m (28 ft), a length of over 3 m (10 ft) and a body weight of 80 kg (176 lbs.).

• Waterfowl (Anseriformes). The largest species in general is the Trumpeter Swan (Cygnus buccinator), 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, the heaviest waterfowl ever recorded was an overweight Mute Swan (Cygnus olor) from Poland, who weighed nearly 23 kg (50 lb). The members of the previously mentioned Dromornithidae are now classified as members of this order, making them the largest "waterfowl" that ever lived.
• Swifts & allies (Apodiformes). The White-naped Swift (Streptoprocne semicollaris) and the Purple Needletail (Hirundapus celebensis) reach similar large sizes, at up to 225 g (8 oz) and 25 cm (10 in). The hummingbirds are also traditionally included in this order, the largest species of which is easily the Giant Hummingbird (Patagona gigas).
• Nightjars & allies (Caprimulgiformes). The largest species of this order is the Great Potoo (Nycitbius grandis), the maximum size of which is about 680 g (1.5 lb) and 60 cm (2 ft).
• Shorebirds (Charadriiformes). The largest species in this diverse order is the Great Black-backed Gull (Larus marinus), attaining a size of as much as 85 cm (34 in) and 2.5 kg (5.5 lb). The extinct Great Auk (Alca impennis), at 5 kg (11 lbs) was the record holder, however.
• Herons & allies (Ciconiiformes). The largest species, if measured in regard to body weight and wingspan, is the Andean Condor (Vultur gryphus), reaching a wingspan of 3.2 m (10.7 ft)^[12] and a weight of 15 kg (33 lb). The longest-bodied species is probably the Saddle-billed Stork (Ephippiorhynchus senegalensis), which often exceeds 1.5 m (5 ft) tall. Most of the largest flying birds in the fossil record, including the largest, Argentavis magnificens, were members of the Ciconiiformes.
• Mousebirds (Coliiformes). The mousebirds are remarkably uniform, but the largest species is seemingly the Speckled Mousebird (Colius striatus), at 57 g (2 oz) and over 35 cm (14 in).
• Pigeons (Columbiformes). The largest species of the pigeon/dove complex is the Victoria Crowned Pigeon (Goura victoria). Some exceptionally large ones have reached 3.7 kg (8.2 lb) and 85 cm (34 in). The extinct dodo (Raphus cucullatus), however, was the largest bird of this order of all time, weighing about 23 kg (50 pounds).
• Kingfishers & allies (Coraciiformes). The largest species is the Southern Ground Hornbill, reaching sizes of as much as 6 kg (13.5 lb) and nearly 1.2 m (4 ft) in length.
• Cuckoos & allies (Cuculiformes). The largest species of this order is the Great Blue Turaco (Corythaeola cristata), a cousin of the cuckoos. This species, which can weigh over 1.2 kg and measure over 74 cm in length, is much larger than other turacos.
• Birds of prey (Falconiformes). The largest species is the Eurasian Black Vulture (Aegypius monachus), attaining a maximum size of 14 kg (31 lb), 119 cm (47 in) long and 3 m (10 ft) across the wings. Slightly larger, at up to 1.4 m (4.7 ft) long, 3 m (10 ft) across the wings and weighing at least 15 kg (33 lb), was the now extinct Haast's Eagle (Harpagornis moorei), the largest eagle ever.

• Gamebirds (Galliformes). The largest member of this diverse order is the Wild Turkey (Meleagris gallopavo). The largest specimen ever recorded was just short of 14 kg (31 lb) and 130 cm (52 in). The heaviest domesticated turkey on record weighed in at 37 kg (81 lb).^[12] The longest species, if measured from the tip of the bill to the end of the long tail coverts, is the Green Peafowl (Pavo muticus), at up to 3 m (10 ft) long. A prehistoric, flightless family, sometimes called (incorrectly) "giant megapodes" (Sylviornis) were the biggest galliformes ever, having reached 1.70 m (5.6 ft) long and weighed up to about 30 kg (66 lb).
• Loons (Gaviiformes). The largest species on average is the Yellow-billed Loon (Gavia adamsii), at up to 1 m (3.3 ft) and 7 kg (15.4 lb). However, one exceptional Common Loon weighed 8 kg (17.6 lb), heavier than any recorded Yellow-billed Loon.
• Cranes & allies (Gruiformes). The Great Bustard (Otis tarda) and Kori Bustard (Ardeotis kori) are the heaviest birds capable of flight, both occasionally reaching 21 kg (46 lb)^[12] and 1.5 m (5 ft) long. The tallest and longest bird flying bird on earth, also represented in the Gruiformes, is the Sarus Crane (Grus antigone), sometimes standing almost 2 m (6.6 ft) tall. The largest ever gruiform was a species of "terror bird", highly predatory, flightless birds of South America: Brontornis burmeisteri. This species stood about 2.8 m (9.2 ft) and weigh up to about 400 kg (880 lb).

• Songbirds (Passeriformes). Both the Common Raven (Corvus corax) and the Thick-billed Raven (Corvus crassirostris) are enormous by songbird standards. Both of these birds can exceed 1.5 kg (3.3 lb) and 70 cm (28 in).
• Cormorants & allies (Pelecaniformes). The largest species is the Dalmatian Pelican (Pelecanus crispus), which attains a length of 1.82 m (6 ft), a wingspan of 3.5 m (11.5 ft) and a body weight of 15 kg (33 lb). A pelecaniform of the last Miocene, Osteodontornis, was the largest-winged bird ever, after Argentavis, at up to 6 m (20 ft) across and 2.1 m (7 ft) long.
• Flamingos (Phoenicopteriformes). The largest flamingo is the Greater Flamingo (Phoenicopterus ruber), at up to 1.5 m (5 ft) tall and 4 kg (8.8 lb).
• Woodpeckers & allies (Piciformes). The largest species of this diverse order is the Toco Toucan (Ramphastos toco). The maximum size of this tropical forest bird is possibly as much as 1 kg (2.2 lb) and 75 cm (30 in).
• Grebes (Podicepiformes). The largest species of grebe is the Great Grebe (Podiceps major). It can reach a length of 80 cm (32 in) and a weigh of over 2 kg (4.4 lb).
• Tubenoses (Procellariiformes). The largest species is Wandering Albatross (Diomedea exulans), also the bird with the longest wingspan of any living bird. The maximum dimensions are a length of 1.44 m (4.6 ft) and a wingspan of 3.63 m (nearly 12 ft).^[12] Immatures have weighed as much as 13.8 kg (35 lb) at the time of their first flights. The largest-ever tubenose (though it is sometimes classified in the order Pelecaniformes) was the albatross-like Gigantornis eaglesomei, with a wingspan of about 6 m (20 ft).^[13]
• Parrots (Psittaciformes). The longest and largest overall parrot is the endangered Hyacinth Macaw (Anodorhynchus hyacinthinus), reaching nearly 56 m (4 ft) long and 2 kg (4.4 lb). However, the heaviest parrot is the nearly-extinct Kakapo (Strigops habroptilus), which can weigh over 32 kg (8.8 lb), but doesn't much exceed 60 cm (2 ft).
• 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).
• Penguins (Sphenisciformes). The largest species is easily the Emperor Penguin (Aptenodytes forsteri), with a maximum size of 1.35 m (4.3 ft) and 46 kg (102 lb). At one time, possibly to compete with the mammalian pinnipeds, a number of giant penguins existed. The largest is believed to be Anthropornis nordenskjoeldi, having reached a height of nearly 2 m (6.7 ft) and a weigh of up to 135 kg (300 lb).

• Owls (Strigiformes). Both the Eurasian Eagle Owl (Bubo bubo) and Blakiston's Fish Owl (Bubo blakistoni) reach very large sizes. Record-sized specimens of both species have weighed in the ballpark of 4.5 kg (10 lb) and measured over 80 cm (32 in) long. The largest owl known to have existed was Ornimegalonyx oteroi of Cuba, having measured over 1 m (3.3 ft) tall.
• Tinamous (Tinamiformes). The largest species of tinamou, a group of chunky, elusive ground-birds from tropical America, is the Grey Tinamou (Tinamus tao). 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) is much larger than most trogons. It often exceeds 225 g (8 oz) and is at least 35 cm (14 in) along the head-and-body, with the remarkable tail of the male adding 60 cm (2 ft) to the length.

Amphibians (Amphibia)

The largest living amphibian is the Chinese Giant Salamander (Andrias davidianus). The maximum size of this river-dweller is 64 kg (140 lb) and 1.83 m (6 ft). Before aminotes became the dominant tetrapods, several giant amphibian-like tetrapods existed. The largest known was the crocodile-like Prionosuchus, which reached a length of 9 m (30 ft).

• Frogs (Anura). Easily the largest member of the largest order of amphibians is the African Goliath frog (Conraua goliath). The maximum size of this species is a weight of 3.8 kg (8.4 lb) and a snout-to-vent length of 35 cm (14 in). The largest of the toads is the Cane Toad.
• Caecilian (Gymnophiana). The largest of the worm-like caecilians is the Thomson’s Caecilian (Caecilia thompsoni), which reaches a length of 1.5 m (5 ft) and can weigh up to about 1 kg (2.2 lb).

Ray-finned bony fish (Actinopterygii)

The largest living bony fish is the ocean sunfish, a member of the order Tetraodontiformes. Sunfish have been recorded at sizes as large as a length of nearly 3.6 m (12 ft), a height of 4.5 m (15 ft) from fin to fin and a weight of about 2,273 kg (5,000 lb). Much larger bony fish existed prehistorically, the largest ever known having been Leedsichthys, of the Jurassic period. Estimates of the size of this fish range from 13.5 m (45 ft) to 30 m (100 ft), but a maximum size of 22 m (72 ft) seems most realistic.

• Sturgeons (Acipenseriformes). The largest species is the huge beluga sturgeon (Huso huso). The maximum recorded size of this endangered species is nearly 7.9 m (26 ft) and 2,075 kg (4,565 lb). The Kaluga or Great Siberian Sturgeon has been recorded at 1000 kg, making it the largest known freshwater fish.
• Eels (Anguilliformes). The largest species, if measured in weight and overall bulk, is the European conger (Conger conger). The maximum size of this species is 2.87 m (9.5 ft) and 111 kg (245 lb). Getting slightly longer, at up to 3 m (10 ft) but never exceeding 36 kg (80 lb), is the giant moray (Gymnothorax javanicus).
• Minnows & allies (Atheriniformes). An order best known for its small minnow respresentatives, the largest species is the jacksmelt (Atherinopsis californiensis). 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). Slender, with a huge, dramatic spine, these fish can reach 5.4 kg (12 lb) and 2.1 m (7 ft).
• Toadfish (Batrachoidiformes). The largest toadfish is the Pacuma toadfish (Batrachoides surinamensis), reaching a size of up to 2.27 kg (5 lb) and 58 cm (23 in).
• Flying-fish & 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 Agujon needlefish (Tylosurus acus), a slender fish at up to 1.5 m (5 ft) and a weight of 3.7 kg (8.2 lb).
• Squirrelfish (Beryciformes). Best known for their highly poisonous barbs, the squirrelfish largest respresentative is the giant squirrelfish (Sargocentron spiniferum), at up to 60 cm (24 in) and 3.5 kg (7.7 lb).
• Characins (Characiformes). The largest species is the giant tigerfish (Hydrocynus goliath). The top size of this fish is 1.5 m (5 ft) and 70.5 kg (155 lb).
• Herring (Clupeiformes). The largest herring is probably the Dorab wolf herring (Chirocentrus dorab). The maximum size of this species has been reported as much as 1.83 m (6 ft), but these slender fish have never been recorded as exceeding 3.4 kg (7.5 lb) in weight.
• Carp (Cypriniformes). The largest species today is probably the giant barb (Catlocarpio siamensis), which 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) was reported to reach similar or even larger proportions, but large specimens are quite rare recently.
• Killifish & allies (Cyprinodontiformes). The largest species is the Pacific four-eyed fish (Anableps dowei), reaching a size of 33 cm (13 in) and 588 g (1.3 lb).
• Cod (Gadiformes). The largest cod species, although it rarely reachs large sizes anymore due to heavy fishing, is the Atlantic cod (Gadus morhua). The maximum recorded size of this species is 2 m (6.7 ft) long and 96 kg (212 lb).
• Shellears & 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.
• Ribbonfish & allies (Lampriformes). The largest member of this small but fascinating order is the oarfish (Regalecus glesne), also the longest bony fish on earth. Slender and compressed, this fish averages over 6 m (20 ft) long and can weigh 275 kg (605 lb). One fish was 11.3 m (37.3 ft) long, but there is a possibility that the oarfish reaches 16 m (55 ft).
• Gars (Lepisosteiformes). The largest of the gar, and the largest entirely freshwater fish in North America, is the alligator gar (Atractosteus spatula), reaching a size of 3 m (10 ft) and 140 kg (310 lb).
• Anglerfish (Lophiiformes). The largest of this diverse order is the common goosefish (Lophius piscatorius). This big-mouthed fish can attain a size of 58 kg (127 lb) and a length of 1.9 m (6.2 ft).
• Lanternfish (Myctophiformes). The largest of the numerous but small lanternfish is Bolin's lanternfish (Gymnoscopelus bolini), at up to 249 g (8.8 oz) and 35 cm (14 in).

• Pearlfish & allies (Ophidiiformes). The largest member of this order is the 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 (Arampaimas giga). This laterally compressed fish can reach a size of about 3 m and a weight of 202 kg (455 lb).
• Perches & allies (Perciformes). The title of the largest member of this order, the largest order of all vertebrates, is a matter of some debate. A large marlin is the biggest of these fishes, as they are known to exceed even the huge northern bluefin tuna (Thunnus thynnus) in size. The black marlin (Makaira indica), the Atlantic blue marlin (Makaira nigricans) and the Indo-Pacific blue marlin (Makaira mazara) all reach similar large sizes, at up to 900 kg (2,000 lb) and 4.7 m (15.5 ft).
• 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 2.67 m (8.8 ft), although fish even approaching this size would be extraordinary these days.

• Salmon & allies (Salmoniformes). The largest species is the Chinook salmon (Oncorhynchus tshawytscha). 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) is largest sculpin. The maximum size is 1.9 m (6.2 ft) and the weight can be 90 kg (200 lb).
• Catfish (Siluriformes). Most authorities now give the crown of the largest catfish to the Mekong giant catfish (Pangasianodon gigas). This huge fish has been recorded at a size of over 3 m (10 ft) and a weight of 356 kg (785 lb). However, the wels catfish (Silurus glanis) may possibly be longer. The largest wels scientifically recorded was 3 m (10 ft) and 220 kg (484 lb).
• Bristlemouths (Stomiiformes). The largest of the bristlemouths is the short-tailed barbeled dragonfish (Opostomias micripnus). The top size of a female of this species is probably over 452 g (1 lb) and 50 cm (20 in) long.
• Seahorses & allies (Syngnathiformes). The largest of this diverse order is the red cornetfish (Fistularia petimba), reaching a length of 2 m (6.6 ft) and weight of over 4.5 kg (10 lb).
• 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)

The largest living cartilaginous fish, of the order Orectolobiformes, is the whale shark, verified in size at up to 13.6 m (45 ft) long and 22 tons (44,000 lb). There are many accounts of larger whale sharks, but most are probably overestimated.

• Whaler sharks (Carcharhiniformes). The largest species of this order is the tiger shark (Galeocerdo cuvier). This species can attain a weight of at least 1527 kg (3,360 lb) and length of possibly as much as 6.4 m (21 ft).
• Mackerel sharks (Lamniformes). The largest living species is the basking shark (Cetorhinus maximus), also the second largest fish. The maximum, verified size for this shark is 12.4 m (41 ft) and weight is 16 tonnes (17.6 tons). An even larger lamnid, generally regarded as the largest predatory fish ever, is the Megalodon, a relative of the great white shark. The top size of this species has probably been exaggerated in the past, but a large Megalodon probably reached 16 m (52.8 ft) and weighed 36 tonnes (40 tons).

• Stingrays & allies (Myliobatiformes). Both the largest species of this order and the largest of the rays is the manta ray (Manta birostris). This peaceful leviathan can reach a size of 3 tonnes (3.3 tons), a "disk" width of 7.6 m (25 ft) and a length of 5 m (16.5 ft).
• Sawfish (Pristiniformes). These little known cartilaginous fish can often reach huge sizes. The largest bulk recorded for a sawfish is for the southern sawfish (Pristis perotteti), which weighed 2.4 tonnes (2.7 tons). At this weight, the sawfish must have measured nearly 9 m (30 ft).
• Skates (Rajiformes). The largest and most diverse order of rays' largest species is the giant guitarfish (Rhynchobatus djiddensis). The top size of the species is 250 kg (550 lbs) and 3.1 m (10.2 ft).
• Dogfish (Squaliformes). The largest member of this order is the Greenland shark (Somniosus microcephalus). This species probably reaches 7.2 m (24 ft) and large specimens weigh over 1,364 kg (3,000 lb).
• Angelsharks (Squatiniformes). The largest of the bottom-dwelling angelsharks is the monkfish (Squatina squatina), attaining a size of 100 kg (220 lb) and 2.42 m (8 ft).

Invertebrates

Sponges (Porifera)

Arguably the most primitive form of "animals" in existence, the largest species of sponge is the barrel sponge (Xestospongia muta). These massively-built sponges can reach 2.42 m (8 ft) in height and can be of about the same number of feet across the thickest part of the "body".

• 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)

The lion's mane jellyfish is the largest cnidaria species, of the class Scyphozoa. The largest specimens of this giant can attain a bell diameter of 2.5 m (8 ft), a weight of 150 kg (330 lbs.) and can possess tentacles as long as 40 m (120 ft) or more.

• 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, which can attain a mass of 6 kg (13.2 lb in weight), 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.

Flatworms (Platyhelminthes)

The largest terrestrial species of this phylum of mostly parasites, called flatworms in common language, is the greenhouse planarian (Bipalium kewense), of the class Turbellaria. 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 attacking humans and livestock. One of these flukes can be up to 7.5 cm (3 in) long and 2 cm (0.8 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 20 m (66 ft) in the internal organs of a human, and a length of 30 m in other hosts.

Roundworms (Nematoda)

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

Segmented worms (Annelida)

The largest of the segmented worms is the African giant earthworm (Microchaetus rappi). This huge worm can reach a length of as much as 6.7 m (22 ft)^[14] and can weigh over 1.5 kg (3.1 lb). 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 starfish species, Thromidia catalai, of the class Asteroidea, which reaches a weight of over 6 kg (13.2 lb). However, at a maximum span of 63 cm (25 in), it is quite a bit shorter than some other enchinoderms. The longest-bodied enchinoderm is the brisingid starfish Midgardia xandaros, reaching a span of 1.4 m (4.5 ft), despite being quite slender.

• 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). In the past, crinoids grew much larger, and stalk lengths up to 40 m (130 ft) have been found in the fossil record. ^[15]
• Sea-urchins & 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.
• Brittle stars (Ophiuroidea). The largest known specimen of brittle star is Gorgonocephalus stimpsoni. This species can measure 70 cm (28 in) in arm length and has a disk diameter of about 14.3 cm (5.63 in).

Ribbon worms (Nemertea)

The largest nemertean, and the longest extant 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).^[16]

Mollusks (Mollusca)

Both the largest mollusk and the largest of all invertebrates is believed to be the Colossal Squid (Mesonychoteuthis hamiltoni). Current estimates put its maximum size at 12–14 metres (39–46 feet) long, based on analysis of smaller specimens. On February 22, 2007, authorities in New Zealand announced the capture of the largest colossal squid seen. It was later measured at 10 meters (33 feet) long and 494 kilograms (1,098 lb) in weight.^[17]

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. The giant squid can measure up to 13 m (43 ft) or more from tentacle tip to tail tip, or 2.25 m (7.4 ft) in mantle length, and can weigh up to 275 kg (600 lb).^[18]

• 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).
• 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 is 273 kg (600 lb), 1.16 m (3.85 ft) in length and 76 cm (30 in) wide. The largest bivalve ever was Platyceramus platinus, a Cretaceous giant that reached an axial length of up to 3 m (nearly 10 feet).^[19]
• Gastropods (Gastropoda). The largest of this most diverse and successful mollusk class is the Trumpet or Baler Conch (Syrinx aruanus), reaching a size of 16.4 kg (36 lb), a length of 70 cm (28 in) and a width of 96 cm (38 in). The largest of the terrestrial snails is the Giant African Snail (Achatina fulica), 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 North Pacific Giant Octopus (Enteroctopus dofleini), can be very large. The largest confirmed weight of a giant octopus is 71 kg,^[20] with a 23 ft (7 m) arm span.^[21]

Arthropods (Arthropoda)

The Japanese spider crab (Macrocheira kaempferi), a crustacean of the class Malacostraca, is the largest arthropod in the world in overall size, weighing up to 20 kg (44 lb), having a body up to 60 cm (2 ft) long and having a leg span of almost 4 m (13 ft). It is indisputably the largest member of Brachyura (crabs).

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 dimension. This lobster has been recorded at heavier weights, up to 22 kg (48.4 lb), and can measure 1.18 m (3.9 ft) along the body.

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). Its legs may span 1 m (3.25 ft).

The largest arthropod ever known to exist was the Pterygotus, an aquatic eurypterid that was up to 2.3 meters (7.5 feet) in length. The closest living relatives of Eurypterida are the arachnids, horseshoe crabs, and sea spiders.

• Arachnids (Arachnida). The largest species of arachnid is probably the Goliath birdeater (Theraphosa blondi). However, of very comparable dimensions and possibly even greater mass, are the Chaco golden knee (Grammostola aureostriata) and the Brazilian salmon pink (Lasiodora parahybana). Any of these huge New World "tarantulas" have been recorded as reaching a leg width of 28 cm (11 in), a body length over 9 cm (3.5 in) and a body weight exceeding 85 g (3 oz), making them dinner plate-sized spiders. The largest of the scorpions is the species Heterometrus swammerdami. The overall length of this predator can reach 29 cm (11.5 in) long and a weight of up to 57 g (2 oz).
• Branchiopods (Branchiopoda). The largest of these primarily freshwater crustaceans is probably Branchinecta gigas, which can reach a length 10 cm (3.9 in).
• Centipedes (Chilopoda). The biggest of the centipedes is the Amazonian giant centipede (Scolopendra gigantean), reaching a relatively enormous length of 33 cm (13 in).
• Millipedes (Diplopoda). Two species of millipede both reach a very large size Graphidostreptus gigas and Scaphistostreptus seychellarum. Both of these species can slightly exceed a length of 28 cm (11 in). 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 & allies (Maxillopoda). The largest species is a copepod (Pennella balaenopterae), known exclusively as a parasite from the backs of Fin Whales. 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 of these small and little-known but numerous crustaceans is the species Gigantocypris agassizii, reaching a maximum length of 3 cm (1.3 in).
• Amphipods, Isopods, and allies (Peracarida). The largest species is the giant isopod, 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).

Insects (Insecta)

Insects, which are a type of arthropod, are easily the most numerous group of organisms on the planet, with about a million species identified so far. The title of heaviest insect in the world has many rivals, the most frequently-crowned of which is the larval stage of the goliath beetle (Goliathus goliatus), the top size of which is at least 115 g (4.1 oz) and 11.5 cm (4.5 in).^[22] The largest confirmed weight of an adult insect is 71 grams for a giant weta (Deinacrida heteracantha),^[23] although it is likely one of the elephant beetles (Megasoma elephas & Megasoma actaeon) or goliath beetles, both of which can commonly exceed 50 g (3 oz) and 10 cm (4 in), can reach a higher weight.

The longest insects are the stick insects, see below.

Representatives of the extinct dragonfly-like order Protodonata such as the Carboniferous Meganeura monyi and the Permian Meganeuropsis permiana are the largest insect species ever known. These creatures had a wingspan of some 70 cm (28 in) and a body weight of over 452 g (1 lb), making them about the size of a crow.

• Cockroaches (Blattodea). The largest cockroach is the 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).
• Beetles (Coleoptera). The beetles are the largest order of organisms on earth, with about 350,000 species so far identified. The true largest species are the Goliathus, Megasoma and Titanus beetles already mentioned. However, the longest-bodied species is the Hercules beetle (Dynastes hercules), reaching a maximum size of at least 19 cm (7.5 in). Much of the length is comprised of the antennae, and the top weight is 85 g (3 oz), about an ounce less than the bulkier beetles.
• Earwigs (Dermaptera). The largest of the earwigs is the St. Helena earwig (Labidura herculeana), which is up to 8.4 cm (3.3 in) in length.
• True flies (Diptera). The largest species of this huge order is the species Mydas heroes, which can reach a length of 6 cm (2.4 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 are handily outweighed by Mydas.
• Mayflies (Ephemeroptera). The largest mayflies are members of the Proboscidoplocia genus from Madagascar. These insects can reach a length of 5 cm (2 in).
• True bugs (Hemiptera). The largest species of this diverse, huge order is the giant water bug (Lethocerus maximus). This species can attain a size of 11.6 cm (4.6 in), although it is more slender and thus less heavy than most other insects who reach such a size (principally the huge beetles).
• Ants & allies (Hymenoptera). The absolute largest of the ants, and the heaviest species of the order, is the females of Dorylus helvolus, reaching a size of 5 cm (2 in). The ant that averages the largest for the mean size of the whole colony is Dinoponera gigantea, averaging up to 3.3 cm (1.3 in). The largest of the bee species, also in the Hymenoptera order, is Megachile pluto, the females of which can be 3.8 cm (1.5 in) long, with a 6.3 cm (2.5 in) wingspan. Meanwhile, the largest of the wasp is probably the so-called tarantula hawk species Pepsis pulszkyi, at up to 6.8 cm (2.8 in) long and an 11.6 cm (4.6 in) wingspan, although many other Pepsis approach a similar size.
• Termites (Isoptera). The largest of the termites is the African species Macrotermes bellicosus. The huge larvae of this species can attain a size of 10.6 cm (4.2 in) and 5.5 cm (2.2 in) wide; the adults, on the other hand, don't exceed about a third of the size of the larvae.

• Moths & allies (Lepidoptera). The largest species is probably either the Queen Alexandra's birdwing (Ornithoptera alexandrae), a butterfly, or the Atlas moth (Attacus atlas), a moth. Both of these species can exceed a length of 8 cm (3.2 in), a wingspan of 28 cm (11 in) and a weight of 12 g. Their larvae can weigh up to 58 g (1.9 oz). However, the White Witch (Thysania agrippina) has the longest recorded wingspan of the order, and indeed of any living insect, at up to at least 30 cm (12 in). The white witch is exceeded in surface area and mass by both Ornithoptera and Attacus.
• Praying mantises (Mantodea). The largest species of this order is the Chinese mantis (Tenodera aridifolia). The females of this species can attain a length of up to 10.6 cm (4.2 in).
• Dragonflies (Odonata). The largest living species of dragonfly is Megaloprepus caeruleata, 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).
• Grasshoppers & allies (Orthoptera). The largest of this widespread, varied complex of insects is the giant weta (Deinacrida heteracantha) of New Zealand. This formidable insect can weigh over 75 g (2.6 oz) and measure up to nearly 10 cm (4 in), rivaling the huge beetles in size.
• Stick insects (Phasmatodea). The largest stick insect and the longest-bodied insect in the world is the giant stick insect (Phobaeticus kirbyi). The body alone measures up to 30 cm (12 in), while the overall length (from the hind to the front legs) is up to 51 cm (20 in), and the body weight is up to 72 g (2.5 oz).
• Stoneflies (Plecoptera). The largest species of stonefly is Pteronarcys californica, a species favored by fishermen for use. This species can attain a length of 5 cm (2 in) and a wingspan of nearly 7.5 cm (3 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 (0.4 in).
• Fleas (Siphonaptera). The largest species of flea is Hystrichopsylla schefferi. This parasite is known exclusively from the fur of the Mountain Beaver and can reach a length of 1.2 cm (0.5 in).
• Thrips (Thysanoptera). Members of the genus Phasmothrips are the largest kinds of thrips. The maximum size of these species is approximately 1.3 cm (0.5 in).

Plants

The largest single-stem plants are all members of the conifer division. By volume and mass, the largest tree is the Giant Sequoia (Sequoiadendron giganteum). They grow to an average height of 70 – 85 m (230 – 280 ft) and 5 – 7 m (16 – 23 ft) in diameter. Specimens have been recorded to be up to 93.6 m (307 ft) in height and (not the same individual) 8.85 m (29 ft) in diameter; the largest individual is the General Sherman tree, with a volume of 1,489 m³. Although not so large in volume, the closely related Coast Redwood (Sequoia sempervirens) is taller, reaching a maximum height of 115.25 m (380.3 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.

• Algae. 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 60 m (200 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 largest moss is Dawsonia superba, of New Zealand. This species can be 50 cm (20 in) tall.^[24]
• Horsetails (Equisetophyta). The largest of horsetails 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 (Pteridophyta). The largest species of fern is the majestic King Fern (Angiopteris evecta), of the Australasian area. A single frond of this plant can exceed 5 m (16.5 ft) in height.
• Conifers (Pinophyta). Besides the giant Sequoiadendron and Sequoia already mentioned, 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 35.87 m (118.3 ft) and a diameter of 11.42 m (37.5 ft) at 1.5 m (5 ft) above ground level.
• 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 17 m (56 ft) tall and have had a diameter of over 50 cm (20 in).
• Flowering plants (Magnoliophyta). This is the most diverse and numerous division of plants, with upwards of 400,000 species. Typically the largest flowering plant (angiosperm) has been considered Eucalyptus regnans, which can reach heights of 92 m (304 ft)http://www.forestrytas.com.au/forestrytas/tasfor/tasforests_12/tasfor_12_09.pdf.

Stands of trees connected to a single root system (a single organism genetically) may be considered the largest organisms, and the largest flowering plants. The largest known such colony is a male Aspen in Utah, nicknamed Pando (Populus tremuloides), which is estimated to weigh in at approximately 6,000 tonnes (6,615 tons).^[4]

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 Sea near the Balearic Islands, Spain. Its length is about 8 km (4.3 miles). Although this plant has not yet proved itself to be a single organism, all the samples do have the same DNA. It is also thought to be the oldest living organism in the world since its estimated age is about 100,000 years.

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 (10 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.

Fungi

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 (2200 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 whether it is a truly single organism with all parts of the mycelium connected. In this Armillaria each individual mushroom has only a 5 cm (2 inch) stem and a bell of up to 12.5 cm (5 in) across. There are many other fungi of a larger individual size, the largest being Rigidoporus ulmarius. Rigidoporus is up to 284 kg (626 lb), 1.66 m (5 ft 6 in) tall, 1.46 m (4 ft 10 in) across, and has a circumference of 4.9 m (16 ft 2 in).

Other kingdoms

Among the organisms that are not multicellular, the largest are the slime moulds, such as Physarum polycephalum, some of which can cover an area more than 1,000 cm² (1 sq. foot). The largest species traditionally considered protozoa are giant amoeboids like foraminiferans. One such species, the xenophyophore syringammina fragillissima, can attain a size of 20 cm (8 in).

The largest species of bacterium ever discovered 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. The largest known virus is the mimivirus (Acanthamoeba polyphaga), with mature particles of 400 nm in diameter (icosahedral capsid), 800,000 bases and 900 genes. Later research suggested that it could be up to 800 nm long, 1.2 Mbp and 1,260 genes.

See also

• Smallest organisms
• Deep-sea gigantism
• Giant animal
• Largest body part
• List of "largest" articles

Notes

References

• Wood, The Guinness Book of Animal Facts and Feats. Sterling Pub Co Inc (1983), ISBN 978-0851122359
• ^  The General Sherman Tree, Sequoia National Park at the National Park Service. Accessed 20 August 2005.
• ^  The Humongous Fungus--Ten Years Later at the University of Wisconsin, Department of Botany. Accessed 20 August 2005.

External links

• BBC News report about the largest Armillaria in the world
• Mycologist's site about giant Armillaria in Michigan's Upper Peninsula
• ^  Beale, Bob. 10 April 2003. Humungous fungus: world's largest organism? at Environment & Nature News, ABC Online. Accessed 20 August 2005.
• ^  Amos, Jonathan 8 September 2005. Flying reptiles just got bigger at BBC News, Science/Nature. Accessed 26 March 2007.