'Patagotitan mayorum' – Massive dinosaur replica goes on display in London

A cast of one of the largest dinosaurs ever to stride the Earth goes on display in London Friday, the first time the star exhibit has been seen in Europe since the original was discovered in Patagonia.

At 122 feet (37.2 metres) long, the titanosaur – named Patagotitan mayorum – only just fits into the exhibition hall at London's Natural History Museum.

With its neck extended upwards, it would have been tall enough to poke its head into a five-storey building, according to researchers.

Titanosaurs were the last remaining long-necked sauropod dinosaurs still thriving at the time the species went extinct.

Patagotitan will be a welcome replacement for the museum's longtime dinosaur attraction, the popular Diplodocus "Dippy" replica which was on display until 2017.

The new cast is a replica of one of six titanosaurs found after a farmer in Argentina spotted a giant thigh bone sticking out of the earth in 2010, leading to excavations over a number of years.

"They discovered a graveyard of these animals with six different individuals in the ground," Paul Barrett, the exhibition's science lead told AFP.

"Over about three years, they excavated all these bones... and were able to reveal that they had a new type of gigantic dinosaur... one of the largest animals that's ever walked the Earth," he added.

The titanosaurs lived in the forests of modern-day Patagonia 100 to 95 million years ago during the Late Cretaceous period.

Researchers estimate that in addition to its extraordinary length, it would also have weighed about 57 tonnes.

Mysterious demise

The recently discovered herbivore would have had four column-like legs, and an extremely long neck and tail.

To sustain itself, it would have needed to eat around 130 kilos (286 pounds) of vegetation every day.

All six dinosaurs, which were discovered at the same site, are believed to have died at the same time although the reason for their demise remains a mystery.

"We don't know why they died... It could be that they were taken out by a flood. It could be they were taken out by some other environmental problem like maybe a drought," Barrett said, adding that research was ongoing.

Following the discovery in Argentina, dinosaur experts did 3D scans of each individual bone to create replicas made out of polyester resin and fibreglass, which they mounted on a steel structure.

The giant cast took a firm in Canada more than six months to make, based on the scores of excavated fossil bones.

The real bones would have been far too heavy to put on display, but the fact that they are replicas means visitors are allowed to touch the exhibit.

The replica arrived in London in 32 separate crates meaning "each piece had to be put together like a giant jigsaw puzzle", said Sinead Marron of the Natural History Museum.

Marron said the wider aim of the exhibition was to "tell the story of how an animal like this grew up from an egg that's smaller than a football into this amazing 57-tonne giant."

Interactive games and touchable replicas help bring the story to life.

Visitors will be able to touch the teeth of one of the titanosaur's predators or even step inside its internal organs to see how its lungs, heart and gut all worked together, she added.