The biggest dinosaur in history: Archaeologists reveal 122ft long PATAGOTITAN would have weighed the same as a Boeing 737 (and it wasn't even fully grown)

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A study proclaims a newly named species the heavyweight champion of all dinosaurs, making the Tyrannosaurus rex look like a munchkin.

At 76 tons (69 metric tons), the plant-eating behemoth was as heavy as a Boeing 737.

The researchers named the dinosaur Patagotitan mayorum after the Patagonia region where it was found and the Greek word titan, which means large. 

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A cast of the dinosaur's skeleton is already on display at the American Museum of Natural History. It's so big that the dinosaur's head sticks out into a hallway at the New York museum.

The dinosaur's fossils were found in southern Argentina in 2012. 

Researchers who examined and dated them said the long-necked creature was the biggest of a group of large dinosaurs called titanosaurs.

'There was one small part of the family that went crazy on size,' said Diego Pol of the Egidio Feruglio paleontology museum in Argentina, co-author of the study published Tuesday in the journal Proceedings of the Royal Society B.

The second name honors a ranch family that hosted the researchers.

Six fossils of the species were studied and dated to about 100 million years ago, based on ash found around them, Pol said. 

The dinosaur averaged 122 feet long (37 meters) and was nearly 20 feet high (6 meters) at the shoulder.

A cast of the dinosaur's skeleton is already on display at the American Museum of Natural History. 

This graphic shows the size and weight of the Patagotitan, which may have been the largest animal to ever walk the Earth

It is so big that the dinosaur's head sticks out into a hallway at the New York museum.

Legendary T. rex and other meat-eaters 'look like dwarfs when you put them against one of these giant titanosaurs,' Pol said. 

'It's like when you put an elephant by a lion.'

Scientists have known titanosaurs for a while, but this is a new species and even a new genus, which is a larger grouping, Pol said. 

Another titanosaur called Argentinosaurus was previously thought to be the largest.

'I don't think they were scary at all,' Pol said. 

'They were probably massive big slow-moving animals.'

A replica of the Titanosaur skeleton was installed at New York's Natural History Museum earlier this year 

A replica of a 122-foot-long dinosaur is displayed at the American Museum of Natural History in New York. A study proclaims a newly named species the heavyweight champion of all dinosaurs.

'Getting up. Walking around. Trying to run. It's really challenging for large animals,' he said.

The big question is how did these dinosaurs get so big, Pol said. 

Researchers are still studying it, but said it probably has to do with an explosion of flowering plants at the time. 

Scientists have known titanosaurs for a while, but Patagotitan mayorum is a new species and even a new genus, which is a larger grouping

Fossilised bones (pictured) of six young adult dinosaurs found in the same Patagonian quarry may have belonged to the biggest creature ever to have walked the Earth, say scientists

Along with a forest, it was like an all-you-can-eat buffet for these dinosaurs and they just got bigger.

'It's hard to argue this isn't a big deal when it concerns the (probable) largest land animal ever discovered,' University of Maryland paleontologist Thomas Holtz, who wasn't part of the study, said in an email.

Kristi Curry Rodgers, a paleontologist at Macalester College who wasn't part of the study, praised the work as important. 

Vertebrae and rib bones were among the finds recovered from the quarry (pictured) at La Flecha ranch, Chubut Province, Argentina, in 2013

She said the fact that Patagotitan's bones show signs that they haven't completed their growth 'means that there are even bigger dinosaurs out there to discover.' 

Vertebrae and rib bones were among the finds recovered from the quarry at La Flecha ranch, Chubut Province, Argentina, in 2013.

Scientists now think the fossils belonged to at least six different titanosaurs that died in a floodplain region before being preserved in mud.

A study of the remains suggests that the dinosaurs, dubbed 'Patagotitan mayorum', weighed around 62 tonnes and measured more than 115ft (35m) from nose to tail. 

Scientists now think the fossils belonged to at least six different individuals that died in a floodplain region before being preserved in mud

The titanosaur lived 100 million years ago during the Cretaceous period and was a sauropod, a huge plant-eater with a long tail and neck that stood on four legs. 

The discovery is the first indication that titanosaurs engaged in social activity.

Analysis showed that Patagotitan had a probable body mass of 69 tons (62 metric tonnes).

It was more than 15 per cent heavier than Dreadnoughtus, the largest titanosaur from which a femur (thigh bone) and humerus (forearm bone) have been preserved.

A titanosaur, a silhouette representing the size of a hatchling titanosaur, relationship to a human at birth, tiny titanosaur babies weigh about as much as average human babies, 6 to 8 pounds. But in just a few weeks, they're shedding the tiny descriptor and are at least the size of golden retrievers, weighing 70 pounds, knee-high to a person. And by age 20 or so, they're bigger than school buses

Although some estimates have given another Patagonian titanosaur, Argentinosaurus, the title of biggest land animal ever, with a body mass of more than 80 tonnes, these have not been based on limb measurements and may be unreliable.

Vertebrae from Argentinosaurus suggest it was 10 per cent smaller than Patagotitan, said the researchers led by Dr Jose Carballido, from the Museo Paleontologico Egidio Feruglio in Argentina.

They wrote in the journal Proceedings of the Royal Society B: 'The above-mentioned body mass estimates, as well as these vertebral comparisons, places Patagotitan as the largest known dinosaur species.'

Visitors to the American Museum of Natural History examining a replica of a 122-foot-long dinosaur on display at the American Museum of Natural History in New York.

Patagotitan weighed twice as much as several large sauropods from the earlier Jurassic era, a period when giant beasts such as Giraffatitan (formerly known as brachiosaurus) and Apatosaurus strode the Earth.

Sauropods were the largest land animals that ever lived, and of this group nothing matched the titanosaurs in size.

The scientists wrote: 'Here we describe a new giant titanosaur, which not only represents the largest sauropod described so far but also one of the most complete titanosaur taxa recovered to date.

Patagotitan mayorum (artist's impression) weighed around 62 tonnes and measured more than 115ft (35m) from nose to tail

'The new taxon is represented by at least six different specimens. 

'Based on the taphonomical, histological and ecological data available, we interpret this monospecific sauropod association as the first evidence of social behaviour among giant titanosaurs.'