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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. 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. The organism sizes listed are frequently considered "outsized" and are not in the normal size range for the respective species.
- 1 Plants
- 2 Animals
- 2.1 Vertebrates
- 2.2 Invertebrates
- 3 Fungi
- 4 Protists
- 5 Bacteria
- 6 Viruses
- 7 See also
- 8 References
The largest by wood volume and mass is the giant sequoia (Sequoiadendron giganteum), native to Sierra Nevada and California; it grows to an average height of 70–85 m (230–280 ft) and 5–7 m (16–23 ft) in diameter.
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 for a specimen measuring 30 metres (98 ft), while longer ones, up to 33.4 metres (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 kilograms (220 lb). The largest elephant ever recorded was shot in Angola in 1974. It was a male measuring 10.7 metres (35 ft) from trunk to tail and 4.2 metres (14 ft) lying on its side in a projected line from the highest point of the shoulder to the base of the forefoot, indicating a standing shoulder height of 4.0 metres (13.1 ft).
- Table of heaviest living animals
The heaviest living animals are all cetaceans, and thus also the largest living mammals. Since no scale can accommodate the whole body of a large whale, most whales have been weighed by parts.
|Average total length
|1||Blue whale||110||190||25.5 (84)|
|2||North Pacific right whale||60||120||15.5 (51)|
|3||Southern right whale||58||110||15.25 (50)|
|4||Fin whale||57||120||19.5 (64.3)|
|5||North Atlantic right whale||55||100||15 (49)|
|6||Bowhead whale||54.5||120||15 (49)|
|7||Sperm whale||31.25||57||13.25 (43.5)|
|8||Humpback whale||29||48||13.5 (44)|
|9||Sei whale||22.5||45||14.8 (49)|
|10||Gray whale||19.5||45||13.5 (44)|
- Table of heaviest terrestrial animals
The following is a list of the heaviest wild land animals, which are all mammals. 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.
|Average total length
|1||African bush elephant||4.9||12.7||6 (18): Height*|
|2||Asian elephant||4.15||8.0||6.8 (22)|
|3||African forest elephant||2.8||6.0||6.2 (20)|
|4||White rhinoceros[dubious ]||2.1||4.5||4.4 (14.5)|
|5||Indian rhinoceros||1.9||4.0||4.2 (13.9)|
|7||Javan rhinoceros||1.715||2.3||3.8 (12.5)|
|8||Black rhinoceros||1.1||2.9||4 (13.2)|
The largest extant mammal is the blue whale. The largest extant land mammal is the elephant.
The Permian era Cotylorhynchus, from what is now the southern United States, probably was the largest of all synapsids (most of which went extinct 250 million years ago), at 6 m (20 ft) and 2 tonnes. The largest carnivorous synapsid was Anteosaurus from what is now South Africa during Middle Permian era. Anteosaurus was 5–6 m (16–20 ft) long, and weighed about 500–600 kg (1,100–1,300 lb).
- The largest pelycosaur was the pre-mentioned Cotylorhynchus, and the largest predatory pelycosaurus was Dimetrodon grandis from what is now North America, with a length of 3.1 m (10 ft) and weight of 250 kg (550 lb).
- 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.
The largest living non-avian reptile, a representative of the order Crocodilia, is the saltwater crocodile (Crocodylus porosus) of Southern Asia and Australia, with adult males being typically 3.9–5.5 m (13–18 ft) long. The largest confirmed saltwater crocodile on record was 6.3 m (20.7 ft) 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. A specimen caught alive in the Philippines in 2011 (now enclosed at a zoo) was found to have measured 6.2 m (20.3 ft) in length.
- 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.
|Average total length
|1||Saltwater crocodile||454 (1,000)||2,000 (4,400)||4.5 (14.8)|
|2||Nile crocodile||410 (900)||1,360 (3,000)||4.2 (13.8)|
|3||Orinoco crocodile||380 (840)||1,100 (2,400)||4.1 (13.5)|
|4||Leatherback sea turtle||364 (800)||932 (2,050)||2.0 (6.6)|
|5||Black caiman||350 (770)||1,310 (2,900)||3.9 (12.8)|
|6||American crocodile||335 (739)||1,000 (2,200)||4.0 (13.1)|
|7||Gharial||250 (550)||977 (2,150)||4.5 (14.8)|
|8||American alligator||240 (530)||1,000 (2,200)||3.4 (11.2)|
|9||Mugger crocodile||225 (495)||600 (1,320)||3.3 (10.8)|
|10||Tomistoma||210 (460)||500 (1,100)||4.0 (13.1)|
|11||Aldabra giant tortoise||205 (450)||360 (790)||1.4 (4.6)|
|12||Slender-snouted crocodile||180 (400)||325 (720)||3.3 (10.8)|
|13||Galapagos tortoise||175 (390)||400 (880)||1.5 (4.9)|
- See also: Largest prehistoric animals
- Now extinct, except for theropod descendants, the Aves.
- Sauropods (Sauropoda)
- The largest dinosaurs, and the largest animals to ever live on land, were the plant-eating, long-necked Sauropoda. The tallest and heaviest sauropod known from a complete skeleton is an specimen of an immature Giraffatitan discovered in Tanzania between 1907 and 1912, now mounted in the Humboldt Museum of Berlin. It is 12 m (40 ft) tall and weighed 23–37 tonnes. The longest is a 25 m (82 ft) long specimen of Diplodocus 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 Argentinosaurus, which may have weighed 73 tonnes; Supersaurus which might have reached 35 m (112 ft) in length and Sauroposeidon which might have been 18 m (60 ft) tall. Two other such sauropods include Bruhathkayosaurus and Amphicoelias fragillimus. Both are known only from fragments. Bruhathkayosaurus might have been between 40–44 m (130–145 ft) in length and 175–220 tons in weight according to some estimates. A. fragillimus might have been approximately 58 m long and 122.4 metric tons in weight.
- Theropods (Theropoda)
- The largest theropod is arguably Spinosaurus of the mid-Cretaceous, the largest terrestrial predator known to exist (Although recent evidence suggests that spinosaurs spent a lot of time in the water filling a niche similar to modern day crocodiles and polar bears). Size estimates range from 12.6 to 18 m (41 to 59 ft) long and 7 to 21 tonnes for the largest individual found. The lack of agreement lies in the lack of a complete skeleton, the unknown proportion of the head to the body and the unknown function of the massive sail.
- The largest theropod known from a complete skeleton is the Tyrannosaurus specimen nicknamed "Sue", discovered in South Dakota in 1990 and now mounted in the Field Museum of Chicago. It was 12.3 m (40 ft) long, and weighted 6.8 to 9.1 tonnes depending of the methods used.
- Armored Dinosaurs (Thyreophora)
- The largest thyreophorans were Ankylosaurus and Stegosaurus, from the Late Cretaceous and Late Jurassic periods (respectively) of what is now North America, both measuring up to 9 m (30 ft) in length and estimated to weigh up to 6 tonnes.
- Ornithopods (Ornithopoda)
- The largest ornithopods, were the hadrosaurids Shantungosaurus, a late Cretaceous dinosaur found in the Shandong Peninsula of China, and Magnapaulia from the late Cretaceous of North America. Both species are known from fragmentary remains but are estimated to have reached over 15 m (50 ft) in length and were likely the heaviest non-sauropod dinosaurs, estimated at over 23 tonnes.
- Ceratopsians (Ceratopsia)
- The largest ceratopsians were Triceratops and its ancestor Eotriceratops from the late Cretaceous of North America. Both estimated to have reached about 9 m (30 ft) in length and weighed 12 tonnes.
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 weigh 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 around 1500 ACE. This particular species of 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, the largest member of the now extinct family Teratornithidae, found in Miocene-aged fossil beds of Argentina, 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 (176 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.
|Average total length
|1||Ostrich||104 (230)||156.8 (346)||210 (6.9)|
|2||Southern Cassowary||45 (99)||85 (190)||155 (5.1)|
|3||Northern Cassowary||44 (97)||75 (170)||149 (4.9)|
|4||Emu||33 (73)||70 (150)||153 (5)|
|5||Emperor Penguin||31.5 (69)||46 (100)||114 (3.7)|
|6||Greater Rhea||23 (51)||40 (88)||134 (4.4)|
|7||Dwarf Cassowary||19.7 (43)||34 (75)||105 (3.4)|
|8||Lesser Rhea||19.6 (43)||28.6 (63)||96 (3.2)|
|9||King Penguin||13.6 (30)||20 (44)||92 (3)|
|10||Kori Bustard (male)||14 to 19 kg (31 to 42 lb)||20 kg (44 lb)|
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 proto-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 family Leptodactylidae, one of the most diverse anuran families, also has some very large members. The largest 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). While not quite as large as Ceratophrys cornuta, Leptodactylus pentadactylus is often heavier; it can reach 18.5 cm (7.3 in) long and weigh 0.60 kilograms (1.3 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).
- 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.
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.
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) tentacles can attain a length of up to 50 m (170 ft).
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 the whale tapeworm, Polygonoporus giganticus, which can grow to over 30 m (98 ft).
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 weigh over 1.5 kg (3.3 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.
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 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 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 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).
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).
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 m (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 (60 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 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).
- Bivalves (Bivalvia)
- The largest of the bivalve mollusks is the giant clam, Tridacna gigas. Although even larger sizes have been reported for this 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), a weight of 18 kg (40 lb) 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 (160 lb), with a 7 m (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 (280 lb) but are unverified.
The largest arthropod known to have existed is the eurypterid (sea scorpion) Jaekelopterus, reaching up to 2.5 m (8.2 ft) in body length, followed by the millipede relative Arthropleura at around 2.1 m (7 ft) in length. Among living arthropods, the Japanese spider crab (Macrocheira kaempferi) is the largest in overall size, the record specimen, caught in 1921, had an extended arm span of 3.8 m (12.5 ft) and weighed about 19 kg (41 lb). The heaviest is the American lobster (Homarus americanus), the largest verified specimen, caught in 1977 off of Nova Scotia weighed 20 kg (44 lbs) and its body length was 1.1 m (3.5 ft). The largest land arthropod and the largest land invertebrate is the coconut crab (Birgus latro), 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 ft).
- 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 largest spider by leg-span. 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) 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) and weigh around 60 g (2.1 oz). Another extremely large scorpion is the African Imperial scorpion (Pandinus imperator), which can weigh 57 g (2 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 weight of 15 kg (33 lb), and the aquatic Brontoscorpio, at up to 1 m (3.3 ft) and a similar weight.
- 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 Scolopendra gigantea of the neotropics, reaching a 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.
- 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, with females measuring up to 60 cm (2 ft) in length and 5 kg (11 lb) in weight. 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).
- 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 an 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, a class of Arthropoda, are easily the most numerous class of organisms, with over one million identified species, and probably more undescribed species. The heaviest insect is almost certainly a species of beetle, which incidentally is the most species-rich order of organisms. 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).
Some moths and butterflies have much larger areas than the heaviest beetles, but weigh a fraction as much.
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 yet known to have existed. These creatures had a wingspan of some 75 cm (30 in) and a mass of over 1 lb (450 g), making them about the size of a crow.
- 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 (0.6 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.
- True flies (Diptera)
- The largest species of this 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).
- True bugs (Hemiptera)
- The largest species of this diverse 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).
- 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) and a weight of 8.5 g (0.3 oz). 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.
- 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. Although the White Witch 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.
- 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 at up to 7 g (0.25 oz). The largest species of dragonfly ever is the extinct aforementioned Meganeura, although it is not certain to be included in the modern dragonfly order.
- 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).
- 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.
- Lice (Phthiraptera)
- These insects, which live parasitically on other animals, are as a rule quite small. The largest known species is the hog louse, Haematopinus suis, a sucking louse that lives on large livestock like pigs and cattle. It can range up to 6 mm (0.24 in) in length.
- 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 inch) 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.
- 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.
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 weight of the colony may be as much as 605 tons[vague]. 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 Phellinus ellipsoideus (formerly Fomitiporia ellipsoidea) found on Hainan Island. The fruiting body masses up to 500 kg (1100 lb).
Until F. ellipsoidea replaced it, the largest individual fruit body came from Rigidoporus ulmarius. R. ulmarius can grow up to 284 kg (630 lb), 1.66 m (5.4 ft) tall, 1.46 m (4.8 ft) across, and has a circumference of up to 4.9 m (16 ft).
(Note: the group Protista is not used in current taxonomy.)
- 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). These organisms are unicellular, but they are multinucleate.
- 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).
- The largest stramenopiles are giant kelp from the northwestern Pacific. The floating stem of Macrocystis pyrifera can grow to a height of over 45 m (150 ft).
- Macrocystis also qualifies as the largest brown alga, the largest chromist, and the largest protist generally.
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.
In July 2013, however, a team of French scientists announced the discovery of the peculiar Pandoravirus genus of viruses, which have a size of approximately 1 micron and whose genome contains 1,900,000 to 2,500,000 base pairs of DNA.
- Charismatic megafauna
- Deep-sea gigantism
- Genome size
- Giant animal
- Island gigantism
- Largest body part
- Largest prehistoric animals
- List of long-living organisms
- Lists of organisms by population
- Smallest organisms
- All masses in this article are given in metric tons (that is tonnes).
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