Natural History Museum's famous dinosaur skeleton, nicknamed Dippy the Diplodocus, is being retired - because he is no longer deemed "relevant".
The plaster dinosaur skeleton, which has inspired generations of schoolchildren at the London museum for 109 years, is being taken down from summer 2017. He he will be replaced by the 83 foot long (25.2 metres) real skeleton of a blue whale, suspended and "diving" from the ceiling of the Hintze Hall.
The whale, previously the centrepiece of the Mammal Hall, is said to serve as a potent symbol of both environmental destruction and hope for the future.
Meanwhile, there are plans to preserve Dippy at least for a while, possibly by sending him on a tour of the UK.
Despite his realistic appearance, Dippy is a fake - an exact plaster cast copy of an 85 foot long (26 metres) diplodocus, a giant four-legged sauropod dinosaur that lived in North America 150 million years ago.
Originally installed in the Reptile Gallery in 1905, he was taken apart and stored in the Natural History Museum's basement to avoid damage during the Blitz.
In 1979, he was rebuilt and given pride of place in the central hall.
For the last 35 years, Dippy has greeted visitors filing through the museum's main entrance.
The change is part of a "decade of transformation" planned at the museum by its director, Sir Michael Dixon.
Explaining the decision, Sir Michael said: "As the largest known animal to have ever lived on Earth, the story of the blue whale reminds us of the scale of our responsibility to the planet.
"This makes it the perfect choice of specimen to welcome and capture the imagination of our visitors, as well as marking a major transformation of the Museum.
"This is an important and necessary change.
"As guardians of one of the world's greatest scientific resources, our purpose is to challenge the way people think about the natural world, and that goal has never been more urgent.
"The very resources on which modern society relies are under threat.
"Species and ecosystems are being destroyed faster than we can describe them or even understand their significance.
"The blue whale serves as a poignant reminder that while abundance is no guarantee of survival, through our choices, we can make a real difference.
"There is hope."
The female blue whale has been a resident at the Natural History Museum for longer than Dippy, arriving in 1891, just 10 years after the museum opened.
It was found beached at the mouth of Wexford Habour on March 25 1891, after being injured by a whaler.
In the same year, the skeleton was bought for £250 from a Wexford merchant, to become part of the museum collection.
But the specimen only went on public display in 1938 with the opening of the Mammal Hall, where it is currently suspended over a life-size blue whale model.
Blue whales were hunted to near extinction for their oil, meat and body parts before starting to recover their numbers after being granted protected status.
The blue whale, Balaenoptera musculus, is the biggest animal ever to have lived on Earth.
Weighing up to 160 tonnes, it out-sizes even the largest dinosaur, the 70 tonne Argentinasaurus.
The Natural History Museum welcomes more than five million visitors a year.
It also operates as a world-leading research centre.
Dippy was unveiled at a special ceremony at the museum at 1pm on May 12 1905.
He was donated to the Museum by Scottish-born American millionaire and philanthropist Andrew Carnegie after King Edward VII saw an illustration of the original skeleton and asked for a copy.
The skeleton, which contains 356 plaster cast bones, was constructed over a period of 18 months and shipped to England in 36 crates.
It is a replica of a near-complete Diplodocus skeleton unearthed in Wyoming, US, in 1898 and housed at the Carnegie Museum of Natural History in Pittsburgh.
Sir Michael told the Press Association that Dippy could end up as an additional exhibit in one of the museum's galleries.
Another possibility was laser-scanning his plaster bones to create another replica made of more durable material.
The "new" Dippy would be able to brave the elements outside in the museum grounds.
Sir Michael said: "We've just launched our new five-year plan for the museum, much of which is about what makes a museum special and different.
"The fundamental thing is our fantastic collection of real objects from the natural world. We're focusing on the real and authentic. Much loved as Dippy is, he's a plaster cast replica of a diplodocus, and one of a number around the world.
"We think this is a once-in-a-generation opportunity to re-imagine the main hall.
"This is not about saying Dippy is of no value - he's an icon of the museum - but the new exhibit will allow us to tell a range of stories about the museum and its purpose. One is about the evolution of mammals, which is one of the big narratives the museum likes to talk about. Then we can tell a story about man's exploitation of the natural world. Finally, we can tell the story since 1967 over which time the blue whale population recovered tenfold."
A tour would allow many more people around the UK to see Dippy, said Sir Michael.
"One thing we have to consider is whether a plaster cast over 100 years old is actually durable enough to stand the shock," he added.
Eventually he thought it likely that Dippy would find a place alongside other dinosaurs in the museum.