Picture a giant, duck-billed, camel-backed, feathery omnivore that weighs a massive 7 tons.
It may sound like a hybrid creation straight out of the Jurassic World franchise — but this creature actually roamed the Earth some 70 to 66 million years ago, during the Late Cretaceous period.
“Deinocheirus was a peculiar, humpbacked dinosaur with a duckbill-like skull that grew to Tyrannosaurus size,” says Yuong-Nam Lee, a professor at Seoul National University who helped describe new research on this quirky creature back in 2014.
Prior to the 2014 study, Deinocheirus was known from only two long arms, discovered in Mongolia; this led to its name, which means “terrible hand.” The fossils were uncovered in 1965, but for decades a lack of other finds meant this species remained a mystery.
Paleontologists, including Lee, turned to detective work to uncover more information.
In 2006 and 2009, the Korea-Mongolian International Dinosaur Expedition tracked down fossil specimens that had been poached from excavation sites — a Deinocheirus skull and a pair of feet had made their way from Mongolia to Japan, and finally to Germany.
“We persuaded a private collector that they are important for science,” Lee says. “Finally, I could study almost all elements of Deinocheirus skeletons and know how it looked, how big it was, what it ate.”
These details revealed a dinosaur like no other.
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In general, ornithomimosaurs were ostrich-like dinosaurs that varied widely in size; but Deinocheirus was the biggest of the lot. Lee’s team also found that though the species was a theropod — a group of bipedal, largely meat-eating dinosaurs — this lumbering giant was almost certainly an omnivore.
An analysis of the fossilized stomach remains revealed its diet consisted of fish. But couple this with its weak bite force and indications of a large tongue, it’s quite possible that Deinocheirus also grazed heavily on vegetation as well.
The long forearms, equipped with massive claws, “may have been used for digging and gathering herbaceous plants in freshwater habitats,” Lee says.
With heavily built legs, it was most likely a slow mover. Its large, specifically adapted feet, meanwhile, could have helped it walk through muddy waters as it foraged for food.
Similar to smaller, related dinosaurs, Deinocheirus likely had feathers, too; they may have come in the form of a tail fan, used for display, according to Lee. In sum, “Deinocheirus is one of the weirdest ornithomimosaur dinosaurs beyond our imagination,” he says.
Despite the wealth of information gleaned from the recovered fossil specimens, however, many questions remain about the species.
“There is a rumor that a Deinocheirus juvenile skull was also poached and is present somewhere,” Lee says.
If true, finding and studying it could provide insights into the species’ development and evolution. Perhaps more weird details remain to be learned about this fascinating creature.