This article is more than 1 year old

Long armof of the saur: Brachially gifted dino bone conundrum solved

Deinocheirus mirificus was a bit of a knuckle dragger

The secrets of a long-armed, “totally bizarre” dinosaur have finally been plumbed after bone-boffins unearthed a much fuller specimen of the odd creature.

Deinocheirus mirificus

Since 1965, when scientists in Mongolia dug up two huge dino forearms measuring 2.4m, baffled boffins have wondered what kind of giant lizard they could belong to. Researchers haven’t uncovered any new fossils of the creature, dubbed Deinocheirus mirificus, which means “unique and fearsome hands” in Greek, for over 50 years, until now.

That left scholars guessing at what the dinosaur might be like, with some suggesting that its enormous limbs meant it was likely to be a carnivorous dinosaur bigger and more ferocious than Tyrannosaurus rex.

“We looked for years to find the quarry where the Deinocheirus came from,” said Phil Currie, professor and Canada Research Chair in Dinosaur Paleobiology at the University of Alberta’s Faculty of Science. “We had a map, but it was a hand-drawn, so as you can imagine it was very difficult to find.”

Finally, in 2009, Currie and a group of international researchers called the Korea-Mongolia International Dinosaur Project, discovered an incomplete skeleton from exposed bones in a quarry at Bugiin Tsav that looked like it had been scavenged by poachers.

Artist's impression of Deinocheirus mirificus

“The fossils in the quarry were in bad shape,” said Currie. “The poachers knew what they had, but they only took certain more-saleable parts.”

Luckily, they did leave behind one very recognisable part of a Deinocheirus – a huge left forearm. The remaining bones were enough for the team to establish that they had quite a weird-looking beast on their hands.

Deinocheirus is a totally bizarre dinosaur,” said Currie. “Although the arms have been known since 1965 and have always aroused speculation because of their enormous size and sharp and recurving claws, but we were completely unprepared for how strange this dinosaur looks.

“It almost appears to be a chimera, with its ornithomimid-like arms, its tyrannosaurid-like legs, its Spinosaurus-like vertebral spines, its sauropod-like hips, and its hadrosaur-like duckbill, and foot-hooves.”

At 11m long with a weight of around 6.4 tonnes, it’s a behemoth, but hardly the giant tyrannosaur boffins were expecting. It now looks like the disproportionately large arms were used for digging and gathering plants in freshwater habitats, or for fishing.

“The study of this specimen has shown that even in dinosaurs like Deinocheirus, an animal that has been known for almost half a century, we can still learn surprising things about their anatomy,” said Currie.

“Furthermore, it underlines the fact that even today, dinosaurs are still relatively poorly known. The fact that Deinocheirus is from the Nemegt Formation of Mongolia, one of the richest and most diverse dinosaur faunas known, hints that there are probably thousands of dinosaurs that we still do not know about from the majority of dinosaur localities in the world.” ®

More about

TIP US OFF

Send us news


Other stories you might like