After more than three decades, researchers have discovered two well-preserved specimens of a dinosaur previously known only for its eight-foot arms and hands containing three elongated tree claws, according to research published Wednesday in the Journal Nature.
The armor, hands and shoulder girdle of the creature, known as the Deinocheirus mirificus (Greek for “terrible hand” and “wonderful”), were recovered during the 1965 Polish-Mongolian Paleontological Expedition at Altan Uul III in the southern part of Mongolia’s Gobi Desert and detailed in the Polish Academy of Sciences monograph series Palaeontologia Polonica four years later.

Several years passed and new fossils belonging to the creature were discovered, and as a result, paleontologists were left to speculate over what the creature actually looked like. Many believed that, due to the size of its limbs, the Deinocheirus would be a massive theropod Rex.

However, as Nature’s Sid Perkins explained, a newly analyzed set of bones discovered at a quarry at Bugiin Tsav in 2009 have shed the most revelatory light, revealing that the dinosaur was 11 meters long, weighed 6.3 metric tons and had both a large beak and a large, leaf-shaped tongue.

It also had a skull that was more than a meter long, lacked teeth and had a keratinous beak used to eate vegetation.

Furthermore, the Huffington Post noted that the creature stood 16 feet tall and would most likely have scattered fruits of feathers. The dinosaur also likely had dorsal spines, and used its “disproportionately large forearms” for digging, gathering plants and/or fishing, said researchers from the University of Alberta who were involved in the study.

“A deep lower jaw probably housed an immense tongue that could have helped to suck up plants from the bottoms of rivers and lakes. Stomach contents preserved in the fossil, including fish vertebrae and scales, suggest that Deinocheirus also consumed large quantities of aquatic prey,” Perkins noted. “As well as its wide hips and broad toes, which helped to prevent it from sinking into soft sediments while foraging.”

“The dinosaur’s arms really stole the show in terms of peculiar bone structures,” said Phil Currie, professor and Canada Research Chair in Dinosaur Paleobiology at the University of Alberta’s Faculty of Science.

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

The remains were discovered by a team of paleontologists led by Yuong-Nam Lee from the Korea Institute of Geoscience and Mineral Resources, and the 70 million-year-old fossils were recovered from sites close to where the original Deinocheirus bones were found. The newly found remains, combined with some bones that were recovered by poachers, accounted for approximately 95 percent of the creature’s skeleton, the study said.

“These new specimens really solve the mystery of what Deinocheirus looked like in its entirety after being known only from just two gigantic arms for the past 50 years,” added Darla Zelenitsky from the University of Calgary. “It’s also sad in a way. As a kid, your imagination would run wild about the nature of these massive arms. That mystery is gone.”