London, Nov.22 : A forgotten museum fossil that had been gathering dust for more than a century is actually from a mysterious British dinosaur that represents an entirely new family, scientists have discovered.

The newly revealed herbivore was identified from a fragment of backbone stored at the Natural History Museum in London since the 1890s.

 The fossil laid unnoticed until 2006, when it was chanced upon by visiting dinosaur researcher Mike Taylor from the University of Portsmouth in England.

Having spent the previous five years "doing nothing but looking at sauropod vertebrae," Taylor immediately realized the half-complete fossil bone was "something strange," reports National Geographic.

"It was unmistakably a dorsal vertebra from a sauropod, but it didn't look like any dorsal vertebrae I'd ever seen before."

Investigation of the foot-tall (30-centimeter-tall) fossil subsequently revealed an unknown species that lived some 140 million years ago, according to findings published in the current issue of Palaeontology, the journal of Britain's Palaeontological Association.

The study was co-authored by University of Portsmouth paleontologist Darren Naish, who Taylor turned to for assistance in identifying his museum find.

"The fossil is not just a little bit different from the vertebrae of other types of sauropod—it's shockingly strange," Naish was quoted, as saying.

"Based on this one bone, Xenoposeidon has more unique features than do other sauropods that are known from almost complete skeletons. That's how strange it is," he added.

Getting an accurate picture of what Xenoposeidon looked like from a single piece of backbone is impossible, the researcher admitted.

If built like a brachiosaur, the dinosaur would have measured some 15 meters (50 feet) long and weighed 7.6 tons, the researchers estimated.

If instead it resembled more lightly framed diplodocoids, Xenoposeidon would have stretched 20 meters (66 feet) nose to tail and weighed about 2.8 tons, the study said.

Fossil collector Philip James Rufford originally discovered the odd vertebra in the early 1890s near Hastings in southeast England.

The fossil was briefly reviewed by paleontologists, then hidden away for 113 years at the Natural History Museum.

Researchers don't know whether other remains of the fossil creature survived, since the museum didn't keep a record of the exact location of the find.

That's not uncommon, Naish said. Hundreds of dinosaurs and other long-extinct animals are known from a single fossil specimen.

But attaching a name to the newly described sauropod bone should increase the chances of future Xenoposeidon discoveries, the researchers said. (ANI)