Largest and heaviest animals
[11][12] The upper estimates of weight for these prehistoric animals would have easily rivaled or exceeded the largest rorquals and sauropods.
[62][63] 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.
[67] 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.
[1] Unconfirmed reports of much larger crocodiles exist, but examinations of incomplete remains have never suggested a length greater than 7 m (23 ft).
[76] 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 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 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.
Unlike mammals, birds, or fish, the mass of large reptiles is frequently poorly documented and many are subject to conjecture and estimation.
[citation needed] The largest living bird, a member of the Struthioniformes, is the common ostrich (Struthio camelus), from the plains of Africa.
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.
This particular species of moa stood up to 3.7 m (12 ft) tall,[172] but weighed about half as much as a large elephant bird or mihirung due to its comparatively slender frame.
[179][178] 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.
[citation needed] 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).
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).
[1] 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).
[241] Current estimates put its maximum size at 12 to 14 m (39 to 46 ft) long and 750 kg (1,650 lb),[242] based on analysis of smaller specimens.
[1][245][246] 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.
[247] The largest roundworm, Placentonema gigantissima,[255] is a parasite found in the placentas of sperm whales which can reach up to 9 m (30 ft) in length.
[258] 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).
[1] 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 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).
[268] 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.
[274] The largest of the sea spiders is the deep-sea species Colossendeis colossea, attaining a leg span of nearly 60 cm (2.0 ft).
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.
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.
The largest known specimen of this giant, found washed up on the shore of Massachusetts Bay in 1870,[320][321] had a bell diameter of 2.5 m (8.2 ft), a weight of 150 kg (330 lb).
[1] 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.
