A rare well-preserved hadrosaur fossil unearthed in North China's Inner Mongolia autonomous region. [Photo/provided to chinadaily.com.cn]

A rare well-preserved hadrosaur fossil has been unearthed in North China's Inner Mongolia autonomous region and is expected to be of huge value for research into how the species evolved, said Chinese archeologists.

More than 90 percent of the bones of the large hadrosaur were intact, including the head, cervical vertebra, limbs and a complete tail bone. It is the most complete dinosaur fossil unearthed in Inner Mongolia in 20 years.

The fossil was first discovered in 2012 in Urad Back Banner, in the northwest of the region and excavation started in June 2013.

More than 300 fossil bone pieces were excavated at the site, weighing a ton in total, said Tan Lin, an engineer with the Longhao Geological Institute of Paleontology in Inner Mongolia.

Chinese researchers said that the fossil structure of the hadrosaur was about eight meters long, one meter wide and five meters tall. It was a mature dinosaur which lived 80 million years ago.

A rare well-preserved hadrosaur fossil unearthed in Inner Mongolia autonomous region. [Photo/provided to chinadaily.com.cn]

Ten workers are restoring the fossil in a storehouse in Chengguan Town, Bayannur city. The work began in May this year and will end in October.

Such a complete dinosaur fossil is a very rare find, said Xu Xing, a researcher with the Institute of Vertebrate Paleontology and Paleoanthropology under the Chinese Academy of Sciences.

It will greatly inform research into the evolution of the hadrosaur species and biology in the Rehe area, he added.

Archeologists also found fossils of other plants and living organisms in the Rehe area, which will prove invaluable in researching the area.

Many dinosaur fossils have been excavated in Inner Mongolia in recent years.