China has uncovered the skeletal remains of a gigantic, surprisingly
bird-like dinosaur, which has been classed as a new species.
Eight metres (26 ft) long and standing at twice the height of a man at the
shoulder, the fossil of the feathered but flightless Gigantoraptor erlianensis
was found in the Erlian basin in Inner Mongolia, researchers wrote in the latest
issue of Nature.
The researchers said the dinosaur, discovered in April 2005, weighed about
1.4 tonnes and lived some 85 million years ago.
According to lines of arrested growth detected on its bones, it died as a
young adult in its 11th year of life.
What was particularly surprising was its sheer size and weight because most
theories point to carnivorous dinosaurs getting smaller as they got more
"It had no teeth and had a beak. Its forelimbs were very long and we believe
it had feathers," Xu Xing at the Chinese Academy of Sciences' Institute of
Vertebrate Paleontology & Paleonanthropology said in a telephone interview.
Through analysing its skeleton, the researchers believe the Gigantoraptor
shared the same ancestor and belonged to the same family as the Oviraptor.
With a beak and feathers, the Oviraptor is also bird-like and flightless, but
weighed a mere 1 to 2 kg, Xu said.
Other similar feathered dinosaurs rarely weighed over 40 kg, which means the
Gigantoraptor was about 35 times heavier.
The largest known feathered animal before the Chinese discovery was the
half-tonne Stirton's Thunder Bird, which lived in Australia more than six
million years ago.
"It's a giant dinosaur that looked very much like a bird ... whereas from
what we have known before, bird-like dinosaurs were very, very small. Large
dinosaurs are usually not bird-like. So this Gigantoraptor was an exception," Xu
If the Gigantoraptor had lived to a full-sized adult, it would have been a
lot larger, but Xu could not estimate what that would have been.
However, the researchers believe it had an accelerated growth rate that was
faster than the large North American tyrannosaurs.
The scientists had originally thought they had found tyrannosaur bones, as
they were so large.
"It was a very surprising discovery, not at all what we expected," Xu said
later at a news conference in Beijing. "So we spent a lot of time investigating
the fossils which is why it took us so long to announce the results."
The scientists showed off two huge fossilised bones from the animal, and a
model of its beaked head.
Its feathers were likely for show and for keeping its eggs warm, Xu added.
"We think it's the largest feathered animal ever to have been discovered," he
It had both herbivorous features -- a small head and long neck -- but also
carnivorous ones -- sharp claws for tearing meat -- and could likely run fast on
its long, powerful legs, the professor said.
"Of course, there's no way of knowing for sure," he added.
Its site of discovery, near Erenhot on the Chinese-Mongolian border, is known
for fossils and calls itself "dinosaur town".
The city of just 100,000 is hoping to leverage this fame to attract tourists,
said its Communist Party chief Zhang Guohua, and will spend more than 100
million yuan ($13.11 million) on a new dinosaur fossil museum this year.