Washington, Oct 23 : One of the oldest known dinosaur relatives of birds had "bizarre" anatomy, including long, ribbon-like tail feathers that suggest plumage may have first evolved for show rather than for flight.
According to a report in National Geographic News, farmers unearthed a fossil of the new dino species, dubbed Epidexipteryx hui, from the hills of Inner Mongolia in late 2007.
The remains date back to 152 million to 168 million years ago, making the newfound creature slightly older than Archaeopteryx, the most primitive known bird.
Like other avialans-birds and their closest dinosaur relatives-Epidexipteryx is a theropod, a group of two-legged animals that includes Tyrannosaurus rex.
Epidexipteryx lived in the mid- to late Jurassic period in a lush, well-vegetated area that was rich in salamanders and other possible prey.
Researchers think that the pigeon-size Epidexipteryx might have used its plumes as flashy ornaments, since it was mostly covered in short feathers that lack the structure necessary for flight.
"For example, the feathers could potentially have played a role in displays intended to attract a mate, scare off a rival, or send a warning signal to other individuals of the same species," said study co-author Fucheng Zhang, a paleontologist at the Chinese Academy of Sciences in Beijing.
"This is very exciting indeed, since it gives us a window into a stage of avialan history just preceding the appearance of the classic 'first bird'," Zhang said.
"It shows that the use of feathers for visual communication-as opposed to other functions such as insulation and flight-was a very early development," he added.
Epidexipteryx's anatomy seems to be a hodgepodge of features taken from a variety of animals.
For instance, its front limb bones and short, bony tail resemble those of living birds. But its short, high skull and large front teeth look like those of small theropods called oviraptors.
"It's not uncommon for features present in one group to appear independently in another," Zhang said of the newfound dino's "bizarre" anatomy.