The Duchess of Cambridge will today open a new gallery at the Natural History Museum.
Kate Middleton will officially open the Treasures gallery, which will house 22 of the most extraordinary specimens to have ever been displayed at the London museum.
She was supposed to have been joined by Sir David Attenborough, but the Natural History Museum said he had to pull out of the event due to unforeseen circumstances.
Michael Dixon, director of the Natural History Museum, said: "We are thrilled Her Royal Highness will join Sir David in helping us celebrate the opening of Treasures.
"We hope that she will be the first of many visitors to discover everything the museum represents in this special gallery."
Showcased in the gallery are rare first editions of Charles Darwin's On the Origin of Species and Audubon's Birds of America.
There will also be the Archaeopteryx fossil, which shows that modern birds are the descedents of meat-eating dinosaurs.
These former missing links lived during the late Jurassic period, around 150 million years ago. The first skeleton was discovered in 1861 in Germany and was later sold to the Natural History Museum.
Another exhibit is a collection of glass models of marine life known as Blaschka models, created by father and son Leopold and Rudolf between 1876 and 1880. The models were based on illustrations from scientific books from the time.
Other features include dinosaur teeth, the lion skull discovered in the Tower of London, a Dodo skeleton and a Neanderthal skull.
The specimens in the Treasures gallery were chosen from 70 million objects from the museum's collections. They span 4.5 billion years.
The Treasures gallery will be a permanent feature at the museum and is free to visit. It officially opens on 30 November.
Dixon added: "The opening of Treasures represents an exciting future for the Natural History Museum. By inviting the world to explore the highlights of our world famous collection in this permanent gallery, many generations of visitors will capture their own unique insight into our natural world."
The Natural History Museum is a familiar landmark to the royal family. In 2009, Prince William was joined by Attenborough to open the Darwin Centre.
At the opening ceremony, Attenborough said: "Never has it been so important to understand the diversity of life on Earth and how it is changing, if we are to tackle many of the issues that humans face today.
"The Darwin Centre will inspire the next generation of naturalists and scientists through its combination of scientific expertise, specimens, public dialogue, film and interactive media. It will enable all of us to explore the wonders of our world and investigate its secrets."