It was preserved raising its beaked head, with feathered wings outstretched in the mud it was mired in when it died 72 million years ago.
The new creature has been named Tongtianlong limosus, "muddy dragon on the road to heaven".
The discovery is published in the journal Nature Scientific Reports.
"It was found at a construction site by workmen when they were dynamiting, so they nearly blasted this thing off the hillside," said University of Edinburgh palaeontologist Dr Stephen Brusatte.
"We almost never knew about this dinosaur."
A few small parts of the fossil were in fact blasted off, but considering the circumstances of its discovery, the fossil is remarkably complete.
"It's about the size of a sheep, and it's part of a group of very advanced bird-like, feathered dinosaurs called oviraptorosaurs," said Dr Brusatte.
"They were basically the last group of dinosaurs to blossom before the asteroid hit."
The specimen comes from rocks belonging to the Nanxiong Formation in Jiangxi Province, southern China.
The researchers, from China and the UK, say the fossil is particularly special for the insight it provides into the evolutionary transition from dinosaurs to birds.
"Modern birds came from dinosaurs," said Dr Brusatte, "and its dinosaurs like Tongtianlong that give us a glimpse of what the ancestors of modern birds would have looked like.
"Fossils like these capture evolution in action."
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A newly discovered species of dinosaur has been identified from an extraordinarily complete Chinese fossil almost destroyed by dynamite.