Researchers have found a new species of long-necked dinosaur that once walked the Earth in what is now China.

The newly-discovered dinosaur, dubbed Qijianglong, was about 50 feet long and is believed to have lived about 160 million years ago in the late Jurassic, the University of Alberta reported. The skeleton of the Qijianglong was discovered by construction workers back in 2006, and was surprisingly complete.

"It is rare to find a head and neck of a long-necked dinosaur together because the head is so small and easily detached after the animal dies," said PhD student Tetsuto Miyashita.

The dinosaur belongs to species belongs to a group called mamenchisaurids, which are known for their unusually long necks. Qijianglong had unique neck vertebrae that were filled with air, making their giant necks extremely lightweight. Interlocking joints in the neck also suggest the appendage was surprisingly stiff and was most flexible when bent vertically.

"Qijianglong shows that long-necked dinosaurs diversified in unique ways in Asia during Jurassic times--something very special was going on in that continent," Miyashita said. "Nowhere else we can find dinosaurs with longer necks than those in China. The new dinosaur tells us that these extreme species thrived in isolation from the rest of the world."

The researchers believe mamenchisaurids evolved into a variety of forms after going extinct in Asia.

"It is still a mystery why mamenchisaurids did not migrate to other continents," Miyashita said.

The researchers suggest the dinosaurs may have been isolated by surrounding seas, but lost the competition with other creatures or succumbed to predators when land bridges appeared in the region.

"China is home to the ancient myths of dragons. I wonder if the ancient Chinese stumbled upon a skeleton of a long-necked dinosaur like Qijianglong and pictured that mythical creature," Miyashita concluded.

The findings were published in a recent edition of the Journal of Vertebrate Paleontology.