'Piltdown' bird fake explained

Archaeoraptor: the tail was added on later

By BBC News Online's Helen Briggs

Forensic analysis of a forged fossil once hailed as a "missing link" between birds and dinosaurs has shed light on its murky origins.

Sadly, parts of at least two significant new specimens were combined in favour of the higher commercial value of the forgery, and both were nearly lost to science

Nature report

Scientists believe that the fake is a mosaic built from at least two, and possibly five, separate specimens.

Two significant fossils were almost lost to science while building the hoax, says an international team from the United States, Canada and China.

The specimen, known as Archaeoraptor, captured the attention of the scientific world when unveiled by the National Geographic Society, US, in October 1999.

It reportedly came from a site in China's Liaoning Province that has yielded a host of exquisitely preserved early birds.

A reconstruction of how the tiny feathered dinosaur might have looked

With its mix of dinosaur and bird-like features, many palaeontologists believed that Archaeoraptor captured the moment in evolution when dinosaurs were experimenting with flight.

But it later emerged that the tail had been glued on to increase the fossil's commercial value before being sold to a dealer.

The tail turned out to be from a new type of bird-like feathered dinosaur - Microraptor - the smallest, adult dinosaur yet discovered.

New bird fossil

Computed Tomography (CT), a technique more common in medical examination, was used to investigate how the forgery was put together.

The analysis was carried out at the University of Texas at Austin, US, in collaboration with experts in China and Canada.

Exposing the fraudsters (Image courtesy of the University of Texas High-Resolution X-ray CT Facility and Nature)

The results suggest that the fossil was built from the front part of the skeleton of an ancient bird, the first of its kind ever seen, cemented on to a slab.

What appear to be random bone fragments of unrelated fossils were stuck on to "complete" the skeleton, making a mosaic that fooled the scientific world.

Dr Timothy Rowe, of the University of Texas at Austin, told BBC News Online: "Now that we know which pieces really do go back together properly and which do not, we can see that there is a new species of extinct bird present in the forgery and that it definitely deserves to be studied and described.

"The tail came from a different animal altogether, and it has already been described and named Microraptor. We may never know where the legs came from."

Piltdown forgery

The Chinese fossil is one in a series of fakes that have fooled paleontologists in the past.

Piltdown man was exposed 40 years after its discovery and recently a dinosaur at the Museum of Wales was shown to be a Victorian hoax.

New forensic techniques, such as those carried out by the Texas team, are increasingly being used to check the authenticity of fossils, said Dr Rowe.

"I would think that insurance companies, auction houses, customs agents, the US Internal Revenue Service, private collectors of fossils, and others with financial stakes in objects like fossils will be concerned and interested in having forensic verification of any specimens that they buy/sell or insure," he told the BBC.