Deinocheirus mirificus, the largest known member of a group of bird-like dinosaurs, is shown in this reconstruction image released on October 21, 2014. Scientists said on Wednesday two almost complete skeletons of the bizarre 70-million-year-old creature, Deinocheirus mirificus (meaning "unusual horrible hand"), show it boasted a combination of unorthodox traits, including the famous arms, never before seen in a single dinosaur.Yuong-Nam Lee/Reuters
Nearly 50 years ago, fossil hunters unearthed the bones of two large, powerful dinosaur arms in Mongolia and figured they had discovered a fearsome critter with killer claws.
Now an international team of paleontologists has found the rest of the dinosaur and they have a new description for it: goofy and weird.
The beast probably lumbered along on two legs like a cross between an ostrich and Jar Jar Binks of Star Wars fame. It stood five metres tall with a duckbill on its head and a hump-like sail on its back. Throw in those killer claws, a few tufts of feathers and a toothless mouth that functioned like a giant vacuum cleaner – and try not to snicker.
That's Deinocheirus mirificus, which means "terrible hands that look peculiar." It is newly reimagined after a nearly full skeleton was found in Mongolia and described in a paper released Wednesday by the journal Nature.
"Deinocheirus turned out to be one the weirdest dinosaurs beyond our imagination," study lead author Young-nam Lee, director of the Geological Museum in Daejeon, South Korea, said in an e-mail.
When scientists in 1965 found the first forearm bones – more than two metres long – many of them envisioned a gigantic creature that would far outsize Tyrannosaurus rex. But with so little to go on, the true nature of the beast, which lived about 70 million years ago, remained a matter of speculation until now.
"We looked for years to find the quarry where the Deinocheirus came from," said Phil Currie, a paleontologist at the University of Alberta who participated in the discovery. "We had a map, but it was a hand-drawn map – so as you can imagine it was very difficult to find."
Originally, the team couldn't locate the dinosaur's skull because poachers had already been removed it from the Mongolian site. Then, Prof. Currie was contacted by a fossil dealer in Europe, which led to a recovery of the skull and other pieces on the private market.
The missing pieces were a perfect match with the Mongolian find, allowing researchers to reconstruct a nearly complete Deinocheirus skeleton. "I was just blown away by the specimen," Prof. Currie said.
The discovery offers a cautionary tale about jumping to conclusions without enough evidence, said University of Chicago dinosaur expert Paul Sereno, who was not involved in the find.
"This is evolution in a dinosaur – not a mammal – world," Prof. Sereno said. "The starting point is a two-legged animal looking somewhat like a fuzzy-feathered ostrich. Now you want to get really big and suck up lots of soft vegetation. In the end you look like a goofy Michelin ostrich with fuzz and a tail – not a cow."
Mr. Lee said the tilted wide hips and massive feet show that Deinocheirus was a slow mover and probably grew so big to escape from being regularly feasted on by bigger dinosaurs. It had a beak that could eat plants, but it also had a massive tongue that created suction for vacuuming up food from the bottoms of streams, lakes and ponds.
Some kids will soon adopt this dinosaur as their favourite, said Thomas Holtz Jr., a paleobiologist with the Smithsonian Institution in Washington. "And those are kids with a sense of humour," he added.
With files from The Associated Press
Ivan Semeniuk