Largest extinct animals

The **largest extinct animals** known to date are listed here. They are arranged by their taxonomy (classification). The list only deals with individual animals; size of colonies (such as coral reefs) is not dealt with here.

### Fish

- Bony fish
The largest bony fish of all time was _Leedsichthys problematicus_ from the Middle Jurassic, at around  long. Earlier claims have been scaled down.
- Cartilaginous fish

The extinct megatoothed shark, _O. megalodon_ is by far the biggest and most powerful shark that ever lived. This giant shark reached a length of more than . Recent higher estimates place the largest individuals of Megalodon at 20.3 meters (66 ft), making it the largest fish of all time.

#### Turtles

The largest fossil turtle seems to be the freshwater turtle _Stupendemys_, with an estimated total carapace length of more than 11 feet (3.3 metres). A close contender is _Archelon ischyros_, a sea turtle, which reached a length of 16 feet (4.8 m) across the flippers and a weight of over 4,850 lb (2,200 kg). For comparison, the largest living turtle is the Leatherback Sea Turtle at a maximum 2000 lbs (900 kg).

#### Archosaurs

- Crocodiles
While often suggested to be the largest crocodilian, _Sarcosuchus imperator_ has been recently cut down to 4 tonnes in weight and 9 meters in length.   _Deinosuchus_, estimated at around , is a strong contender for the title.

#### Pterosaurs

The largest pterosaur was _Quetzalcoatlus northropi_, at 127 kg (280 lbs) and with a wingspan of 11 m (36 ft). Another close contender is _Hatzegopteryx_, also with a wingspan of 11 m (this estimate is based on a skull 3 m long (10 ft).

#### Dinosaurs

- **Sauropods**

Titanosaurs hold the world record for the size of a land animal. A recent discovery in the Argentine found _Dreadnoughtus_, an estimated length of 26 metres (85 feet) and weight of 59,291 kg (65.4 short tons). Its bones showed it was a sub-adult.

A notably large titanosaurid is _Argentinosaurus_, which is known from partially preserved remains. This sauropod has been estimated as  long and 73–99 metric tons in weight. The lack of skeletal material makes these estimates uncertain.

- **Ornithopods**

The very largest ornithopods, like _Shantungosaurus_ were as heavy as medium-sized sauropods at up to 23 metric tons _Lambeosaurus laticaudus_ appears to be close contender at around  in length.

- **Theropods**
The largest known theropod is _Tyrannosaurus rex_, with an exceptionally large specimen nicknamed_Scotty_ estimated at 13m (43ft) long and 8.8 metric tonnes in weight. _Tyrannosaurus Rex_ is also recognized as the largest terrestrial predator yet known.

A close contender in size is a giant theropod from South America, _Giganotosaurus carolinii_, whose holotype specimen is estimated at  in length, and another specimen is estimated at  in length. And _Spinosaurus aegyptiacus_ at 14m (46ft) long and 7.4 metric tonnes in weight. Some other notable giant theropods (e.g. _Carcharodontosaurus_, _Acrocanthosaurus_, and _Mapusaurus_) may also have rivaled these giant theropods in size. Another very large theropod was _Deinocheirus_, being  tall at hips,
and weighing up to 16,000 pounds. The largest dromaeosaurid is _Utahraptor_. In addition to being the largest known dromaeosaurid, it was also the largest known deinonychosaur and the largest known paravian.
- **Armoured dinosaurs**
The largest thyreophoran was _Ankylosaurus_ at  in length and 6.5 tons in weight. _Stegosaurus_ was also 9 meters (30 ft) long but around 5 tons in weight.
- **Ceratopsia**
The largest ceratopsian known is probably the newly discovered _Eotriceratops_ with a skull alone being  in length. Maximum size of this ceratopsian is suggested to be around  in length and 13 tonnes in weight.

#### Ichthyosaurs

The largest ichthyosaur was _Shonisaurus sikanniensis_ at ~21 metres (70 ft) in length. This would make it the largest extinct marine animal.

#### Plesiosaurs

- Long-necked plesiosauridae
The largest plesiosaur was _Mauisaurus haasti_, growing to about 20 metres (66 ft) in length. Next behind was _Elasmosaurus_ at 14 metres (46 ft) long.
- Pliosaurs
There is much controversy here. Fossil remains of a pliosaur nicknamed _Predator X_ were excavated from Norway in 2008. It was about  in length and 41 metric tons in weight. However, in 2002, a team of paleontologists in Mexico discovered the remains of a pliosaur _Monster of Aramberri_, which is also estimated at  in length. However, this specimen is thought to be a juvenile, with evidence that it had been attacked by an even larger pliosaur. Some media claimed that _Monster of Aramberri_ was a _Liopleurodon_ this is unconfirmed.

#### Squamata

- Snakes
The largest known prehistoric snake is _Titanoboa_, estimated at  in length and 1135 kg–1819 kg in weight. Another large fossil snake is _Gigantophis_, estimated at around  in length. Both these snakes lived in tropical rain forests. In third place is an aquatic snake,  _Palaeophis colossaeus_, which may have been around  in length.
- Mosasaurs
Giant mosasaurs are the largest animals in the Squamata. The largest known mosasaur is likely _Mosasaurus hoffmanni_, estimated at least  in length. A close contender in size is _Hainosaurus bernardi_, estimated at  in length. Another giant mosasaur is _Tylosaurus_, estimated at  in length.

### Birds

The largest birds of all time might have been the elephant birds of Madagascar. Of almost the same size was the Australian _Dromornis stirtoni_. Both were about 3 m tall (10 ft). The elephant birds were up to 400 kg and _Dromornis_ was up to 500 kg in weight. The tallest bird ever was the Giant Moa (_Dinornis maximus_) at 12 ft tall.

The largest flight-capable bird was _Argentavis magnificens_ which had a wingspan of 7 m (~23 ft), and a body weight of 110 kg (244 lb), or _Pelagornis sandersi_ with a wingspan of 6.4 to 7.4 metres.

#### Whales

_Basilosaurus_ was once recognized as one of the largest known extinct cetaceans at  in length.

The largest fossil toothed whale was the Miocene whale _Livyatan melvillei_ which was estimated to be  in length. One notable feature of _L. melvillei_ was its teeth which were 36 cm long and is unmatched by any other animal, extinct or alive.

However, the largest fossil whales were baleen whales (plankton feeders) from the Pliocene and Pleistocene Epochs. A notable example is the bones of a Pliocene age baleen whale, assigned the questionable name "_Balaenoptera sibbaldina_", which likely rivaled the modern blue whale in size.

#### Land mammals

The largest perissodactyl, and land mammal, of all time was _Palaeoloxodon namadicus_. It stood 5.5 m (18 ft) tall at the shoulder, with a total height of 8 m (27 ft). It was 12 m (40 ft) long and may have weighed 20 tonnes (22 tons), though mass estimates vary. Some prehistoric horned rhinos also grew to large sizes. The giant woolly rhino _Elasmotherium_ reached 20 ft long and 6.6 ft high.

#### Millipedes (Diplopoda)

The largest by far was the giant _Arthropleura_. Measuring 2.5 metres (8.2 ft) and 45 centimetres (18 in) wide, it was the largest terrestrial arthropod of all time.