Artist's conception of Qijianglong, chased by two carnivorous dinosaurs in southern China 160 million years ago. Lida Xing

A new dinosaur species that is half-neck has been discovered from a skeleton found in China.

The skeleton with its head intact is believed to belong to a 160 million year old new species that sported a neck almost seven metres long.

The dinosaur is about 15 metres in length and was found near Qijiang City.

Belonging to a group of dinosaurs called mamenchisaurids, known for their extremely long necks, the new species differs from most sauropods, or long-necked dinosaurs that have necks only one third the length of their bodies.

"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," explains student Tetsuto Miyashita from (Edmonton) University of Alberta.

The skeleton had neck vertebrae filled with air, rendering their long necks lightweight. Interlocking joints between the vertebrae also indicate a surprisingly stiff neck that was better at bending vertically than sideways.

"Qijianglong", as the skeleton has been named, shows that long-necked dinosaurs diversified in unique ways in Asia during Jurassic times. What kept the species in isolation from the rest of the world could hint at something special going on in the continent then, believes the team.

The fossil site was found by construction workers in 2006.

Mamenchisaurids are only found in Asia, but the discovery of Qijianglong reveals the diversity among mamenchisaurids, according to the paleontologists.

The Qijianglong skeleton is now housed in a local museum in Qijiang.

The findings have been published in a new paper in the Journal of Vertebrate Paleontology.