Largest and heaviest animals

The largest animal currently alive is the blue whale. The maximum recorded weight was 190 tonnes (209 US tons) for a specimen measuring 27.6 metres (91 ft), whereas longer ones, up to 33 metres (108 ft), have been recorded but not weighed. It is estimated that this individual could have a mass of 250 tonnes or more. The longest non-colonial animal is the lion's mane jellyfish (37 m, 120 ft).
In 2023, paleontologists estimated that the extinct whale Perucetus, discovered in Peru, may have outweighed the blue whale, with a mass of 85 to 340 t (94–375 short tons; 84–335 long tons). However, more recent studies suggest this whale was much smaller than previous estimates, putting its weight at 60 to 113 tonnes. While controversial, estimates for the weight of the sauropod Bruhathkayosaurus suggest it was around 110–170 tons, with the highest estimate being 240 tons, if scaled with Patagotitan, although actual fossil remains no longer exist, and that estimation is based on described dimensions in 1987. In April 2024, Ichthyotitan severnensis was established as a valid shastasaurid taxon and is considered both the largest marine reptile ever discovered and the largest macropredator ever discovered. The Lilstock specimen was estimated to be around 26 metres (85 ft) whilst the Aust specimen was an even more impressive 30 to 35 metres (98 to 115 ft) in length. While no weight estimates have been made as of yet, Ichthyotitan would have easily rivalled or surpassed the blue whale. The upper estimates of weight for these prehistoric animals would have easily rivaled or exceeded the largest rorquals and sauropods.
The African bush elephant (Loxodonta africana) is the largest living land animal. A native of various open habitats in sub-Saharan Africa, males weigh about 6.0 tonnes (13,200 lb) on average. The largest elephant ever recorded was shot in Angola in 1974. It was a male measuring 10.67 metres (35.0 ft) from trunk to tail and 4.17 metres (13.7 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 3.96 metres (13.0 ft). This male had a computed weight of 10.4 to 12.25 tonnes.
The heaviest living animals are all whales. Since no scale can accommodate the whole body of a large whale, most have been weighed by parts.
The heaviest land animals are all mammals. The African elephant is now listed as two species, the African bush elephant and the African forest elephant, as they are now generally considered to be two separate species.
The blue whale is the largest mammal of all time, with the longest known specimen being 33 m (108.3 ft) long and the heaviest weighted specimen being 190 tonnes. The extinct whale species Perucetus colossus was shorter than the blue whale, at 17.0–20.1 meters (55.8–65.9 ft) but it is estimated to have rivaled or surpassed it in weight, at 85–340 tonnes. At the highest estimates, this would make Perucetus the heaviest known animal in history.
The largest land mammal extant today is the African bush elephant. The largest extinct land mammal known was long considered to be Paraceratherium orgosensis, a rhinoceros relative thought to have stood up to 4.8 m (15.7 ft) tall, measured over 7.4 m (24.3 ft) long and may have weighed about 17 tonnes. In 2015, a study suggested that the extinct elephant Palaeoloxodon namadicus may have been the largest land mammal ever, based on a fragmentary femur estimated to belong to an individual with maximum weight of 22 tonnes. This author also suggested that the extinct mastodon "Mammut" borsoni may have rivalled P. namadicus in size.
The Late Triassic Lisowicia bojani, from what is now southern Poland, probably was the largest of all non-mammalian synapsids (most of which became extinct 250 million years ago), at 4.5 m (15 ft) in length, 2.6 m (8.5 ft) in height and 9 t (20,000 lb) in weight. However, one study suggested a more conservative weight of 4.87 tonnes to 7.02 tonnes for the adult taxon, with an average body mass of 5.88 tonnes. The largest carnivorous synapsid was Anteosaurus at 5–6 m (16–20 ft) and 500–600 kg (1,100–1,300 lb).
The largest living reptile, a representative of the order Crocodilia, is the saltwater crocodile (Crocodylus porosus) of Southern Asia and Australia, with adult males being typically 3.9–5.5 m (13–18 ft) long. The largest confirmed saltwater crocodile on record was 6.32 m (20.7 ft) long, and weighed about 1,360 kg (3,000 lb). 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. However, due to the difficulty of trapping and measuring a very large living crocodile, the accuracy of these dimensions has yet to be verified. A specimen named Lolong caught alive in the Philippines in 2011 (died February 2013) was found to have measured 6.17 m (20.2 ft) in length.
The Komodo dragon (Varanus komodoensis), also known as the "Komodo monitor", is a large species of lizard found in the Indonesian islands of Komodo, Rinca, Flores, Gili Motang, Nusa kode and Padar. A member of the monitor lizard family (Varanidae), it is the largest living species of lizard, growing to a maximum length of more than 3 metres (9.8 feet) in rare cases and weighing up to approximately 166 kilograms (366 pounds).
Nevertheless, current extant reptiles are still dwarfed by their prehistoric ancestors. The largest non-dinosaurian terrestrial reptile to have ever lived were crocodilomorphs such as Deinosuchus, Sarcosuchus and Purussaurus, each have weight varying between 5-10 metric tons. The largest snake to have ever lived was Titanoboa which could grow up to 12.8–14.3 m (42–47 ft) and weigh up to 730–1,135 kg (1,609–2,502 lb). Prehistoric marine reptiles from the Mesozoic were even larger. Archelon was the largest testudines, being around 4.6 m (15 ft) long from head to tail and 2.2–3.2 t (2.4–3.5 short tons) in weight. Mosasaurus hoffmanni was the largest squamate lizard to have ever lived, with a length of 11 meters (36 ft) and a body mass of 10 metric tons (11 short tons) However, the largest reptiles, period, were the shastasaurids, specifically Ichthyotitan, which approached lengths rivalling to exceeding those of a blue whale, at around 26–35 m (85–115 ft) in length.
The following is a list of the largest living reptile species ranked by average weight, which is dominated by the crocodilians. Unlike mammals, birds, or fish, the mass of large reptiles is frequently poorly documented and many are subject to conjecture and estimation.
Dinosaurs are now extinct, except for birds, which are theropods.
The largest living bird, a member of the Struthioniformes, is the common ostrich (Struthio camelus), from the plains of Africa. A large male ostrich can reach a height of 2.8 m (9.2 ft) and weigh over 156 kg (344 lb). A mass of 200 kg (440 lb) has been cited for the common ostrich but no wild ostriches of this weight have been verified. Eggs laid by the ostrich can weigh 1.4 kg (3.1 lb) and are the largest eggs in the world today.
The largest bird in the fossil record may be the extinct elephant birds (Aepyornithidae) of Madagascar, which were related to the kiwis. Aepyornis exceeded 3 m (9.8 ft) in height and 500 kg (1,100 lb), while Vorombe could reach a similar height and a mass of 732 kg (1,614 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 carnivorous bird was Kelenken, which could reach 3 to 3.2 meters in height and 220 to 250 kilograms. The tallest bird ever was the giant moa (Dinornis maximus), part of the moa family of New Zealand that went extinct around 1500 AD. 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 heaviest 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 5.5 m (18 ft), a length of up to 1.25 m (4.1 ft), a height on the ground of up to 1.75 m (5.7 ft) and a body weight of at least 71 kg (157 lb). Pelagornis sandersi is thought to have had an even larger wingspan of about 6.1–7.4 m (20–24 ft), but is only about 22–40 kg (49–88 lb), half the mass of the former.
The following is a list of the heaviest living bird species based on maximum reported or reliable mass, but average weight is also given for comparison. 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.
The largest living amphibian is the South China giant salamander (Andrias sligoi). Formerly considered conspecific with the Chinese giant salamander (A. davidianus), the maximum size of this nearly human-sized river-dweller is 64 kg (141 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).
The largest tunicate is Synoicum pulmonaria, found at depths of 20 and 40 metres (66 and 131 ft), and are up to 14 centimetres (5.5 in) in diameter. It is also present in the northwestern Atlantic Ocean, around the coasts of Greenland and Newfoundland, but is less common here than in the east, and occurs only at depths between 10 and 13 metres (33 and 43 ft).
The largest thaliacean, Pyrosoma atlanticum, is cylindrical and can grow up to 60 centimetres (2.0 feet) long and 4–6 cm wide. The constituent zooids form a rigid tube, which may be pale pink, yellowish, or bluish. One end of the tube is narrower and is closed, while the other is open and has a strong diaphragm. The outer surface or test is gelatinised and dimpled with backward-pointing, blunt processes. The individual zooids are up to 8.5 mm (0.33 in) long and have a broad, rounded branchial sac with gill slits. Along the side of the branchial sac runs the endostyle, which produces mucus filters. Water is moved through the gill slits into the centre of the cylinder by cilia pulsating rhythmically. Plankton and other food particles are caught in mucus filters in the processes as the colony is propelled through the water. P. atlanticum is bioluminescent and can generate a brilliant blue-green light when stimulated.
The largest lancelet is the European lancelet (Branchiostoma lanceolatum) "primitive fish". It can grow up to 6 cm (2.4 in) long.
The largest species of echinoderm in terms of bulk is probably the starfish species Thromidia gigas, of the class Asteroidea, which reaches a weight of over 6 kg (13 lb), but it might be beaten by some giant sea cucumbers such as Thelenota anax. However, at a maximum span of 63 cm (25 in), Thromidia gigas is quite a bit shorter than some other echinoderms. The longest echinoderm known is the conspicuous sea cucumber Synapta maculata, with a slender body that can extend up to 3 m (9.8 ft). In comparison, the biggest sea star is the brisingid sea star Midgardia xandaros, reaching a span of 1.4 m (4.6 ft), despite being quite slender. Evasterias echinosoma is another giant echinoderm and can measure up to 1 m (3.3 ft) across and weigh 5.1 kg (11 lb).
The largest of the segmented worms (including earthworms, leeches, and polychaetes) 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, including the notorious Eunice aphroditois, reach nearly comparable sizes, reaching 4 and 3.6 m (13 and 12 ft), respectively.
The largest nemertean 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 (in terms of mass) 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 to 46 ft) long and 750 kg (1,650 lb), based on analysis of smaller specimens. In 2007, authorities in New Zealand announced the capture of the largest known colossal squid specimen. It was initially thought to be 10 m (33 ft) and 450 kg (990 lb). It was later measured at 4.2 m (14 ft) long and 495 kg (1,091 lb) in weight. The mantle was 2.5 m (8.2 ft) long when measured.
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 16.8 m (55 ft) in total length (from the tip of the mantle to the end of the long tentacles), head and body length 6.1 m (20 ft), 4.6 m (15 ft) in circumference 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.
The largest roundworm, Placentonema gigantissima, is a parasite found in the placentas of sperm whales which can reach up to 9 m (30 ft) in length.
The largest velvet worm known is Solórzano's velvet worm (Peripatus solorzanoi). An adult female was recorded to have a body length of 22 cm (approximately 8.7 in).
The largest tardigrade is Echiniscoides sigismundi, which is less than 2 mm (0.079 in) long. Typical tardigrades are about 0.5 mm (0.020 in) long. Only the larger tardigrades are visible to the naked eye, but since they're also transparent, magnification is needed to see them.
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 (6.9 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 ft) and weighed about 19 kg (42 lb). The heaviest is the American lobster (Homarus americanus), the largest verified specimen, caught in 1977 off of Nova Scotia weighed 20 kg (44 lb) and its body length was 1.1 m (3.6 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 (3.3 ft).
Both spiders and scorpions include contenders for the largest arachnids.
The largest known thecostracan Facetotecta y-larvae are Hansenocaris cristalabri, about 0.5 millimeters long
The largest crustacean is the Tasmanian giant crab (Pseudocarcinus gigas), with a weight of 13 kilograms (29 lb) and a carapace width of up to 46 centimetres (18 in). It is the only species in the genus Pseudocarcinus. Males reach more than twice the size of females. At a length of up to 40 centimetres (16 in), Lysiosquillina maculata is the largest mantis shrimp in the world. Tasmanian giant freshwater crayfish (Astacopsis gouldi) 5 kilograms (11 lb) in weight and over 80 centimetres (31 in) long have been known in the past, but now, even individuals over 2 kilograms (4.4 lb) are rare. The species is only found in Tasmanian rivers flowing north into the Bass Strait below 400 metres (1,300 ft) above sea level, and is listed as an endangered species on the IUCN Red List.
The four modern horseshoe crabs are of roughly the same sizes, with females measuring up to 60 cm (2.0 ft) in length and 5 kg (11 lb) in weight.
The largest of the sea spiders is the deep-sea species Colossendeis colossea, attaining a leg span of nearly 60 cm (2.0 ft).
Some of these extinct marine arthropods exceeded 60 cm (24 in) in length. A nearly complete specimen of Isotelus rex from Manitoba attained a length over 70 cm (28 in), and an Ogyginus forteyi from Portugal was almost as long. Fragments of trilobites suggest even larger record sizes. An isolated pygidium of Hungioides bohemicus implies that the full animal was 90 cm (35 in) long.
Insects, a class of Arthropoda, are easily the most numerous class of organisms, with over one million identified species, and probably many 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 rainforest or the Goliath beetles, (Goliathus goliatus) and (G. regius), of Africa's rainforest are thought 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 and 15.2 cm (5.2 and 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 Meganisoptera, 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 known to have existed. These creatures had a wingspan of some 75 cm (30 in) and a mass of over 1 pound (450 g), making them about the size of a crow.
The lion's mane jellyfish (Cyanea capillata) is the largest cnidarian 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 (8.2 ft), a weight of 150 kg (330 lb). The tentacles of this specimen 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.
Communities of coral can be truly massive, a single colony of the genus Porites can be over 10 m (33 ft), even though the individual polyps are quite small. In 2024, the largest ever was found off Malaulalo island in the Solomon Islands, a clonal colony of Pavona clavus over 32 by 34 meters — the size of two basketball courts.
The largest known species of sea sponge is the giant barrel sponge, Xestospongia muta. These massively built sponges can reach 2.4 m (8 ft) in height and can be about the same thickness at the thickest part of the "body". Some of these creatures have been estimated to be over 2,400 years of age.