Bird  or Feathered Dinosaur?  Scientists Err on Evolution
Archaeopteryx cast in the Australian Museum, Sydney Denise Chan

The Archaeopteryx, which was long considered the Earth's oldest and most primitive bird might have been a dinosaur after all, according to Chinese scientists.

If this controversial claim is confirmed, the Archaeopteryx can no longer perch at the top and hold the honor of being called the oldest known fossil of the bird species.

Archaeopteryx's fossils are about 150 million years old and were discovered in 1861 in Germany about two years after the publication of Darwin's Origin of Species. The spectacular find provided visual glimpse of evolution. The fossil found had the feathered wings of a bird but teeth and tail of a dinosaur, and throughout the years, theories about the evolution of the bird species heavily relied on Archaeopteryx.

A new report from paleontologist Xing Xu and his colleagues at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, detailed the finding of a similar species, called Xiaotingia zhengi, dating back 155 million years to the Jurassic Period.

The Los Angeles Times reported that the Xiaotingia is a two-pound creature with feathers, sharp claws, fewer than 10 teeth and a small shallow snout like Archaeopteryx, and may have lived in northeastern China's Liaoning province.

The latest report can be found in the journal Nature.

Xu and his team reconstructed a family tree and compared the newly discovered fossil with other similar dinosaurs and early birds, and now believe Archaeopteryx and Xiaotingia are feathery dinosaurs, and should no longer be considered as birds.

"There are many, many features that suggest that Xiaotingia and Archaeopteryx are a type of dinosaur called Deinonychosaurs rather than birds," Xu, told the BBC. "For example, both have a large hole in front of the eye; this big hole is only seen in these species and is not present in any other birds. Archaeopteryx and Xiaotingia are very, very similar to other Deinonychosaurs in having a quite interesting feature - the whole group is categorized by a highly specialized second pedo-digit which is highly extensible, and both Archaeopteryx and Xiaotingia show initial development of this feature."

The origins of the new fossil aren't fully known but it was purchased from a dealer, according to the BBC, which reported that Xu first saw the sample at the Shandong Tianyu Museum and knew it was special.

Should these findings be true, the Archaeopteryx would join another feathered dinosaur named Anchiornis, recently discovered and unearthed by Xu and his team. It is reported to be the oldest feather-bearing animal, even older than the Archaeopteryx by 11 million years.

"If you just looked at Xiaotingia, you'd say, 'Oh, boy, another little feathered dinosaur from China,'" Thomas Holtz, a paleontologist at the University of Maryland at College Park who reviewed the study for Nature, said in Cosmic Log on MSNBC. "In and of itself, it is not a particularly unusual animal. But the combination of traits, at least in their analysis, pulls Archaeopteryx over to the deinonychosaur side of things."

With the Archaeopteryx possibly being dethroned, there may be opportunities for other species such as the Sapeornis and Epidexipteryx to shed light as the oldest bird in the family tree.