HOHHOT -- China has listed the remains of a big, bird-like dinosaur as a national gem for top protection, said authorities in the northern Inner Mongolia autonomous region, where the fossil was found seven years ago.

The skeletal remains were accidentally discovered in the Erlian basin in Inner Mongolia in April 2005.

The feathered, but flightless "Gigantoraptor erlianensis" was eight meters long, over five meters tall and weighed about 1.4 tonnes.

Researchers said the dinosaur lived some 85 million years ago and died as a young adult in its 11th year, indicating it would have been much larger had it lived to a full-sized adult.

"National protection of the fossil is crucial to further research on the origin of life, biological evolution and climate changes," said a spokesman of the land and resources bureau in Erenhot city.

Meanwhile, he said the move would help improve public awareness of heritage protection and crack down upon unauthorized excavation and smuggling of fossils that were once rampant in Erenhot, a city on the Chinese-Mongolian border known as "dinosaur town."

The dinosaur fossil was among the first items included on Ministry of Land and Resources' list of fossils for protection, said Jia Yueming, curator of China geological museum.

The list will be expanded to eventually include 400 kinds of animal fossils, he said.