Meet Deinocheirus mirificus -- "unusual horrible hand"!!! Discovered in 1965 in Mongolia by a joint Polish-Mongolian team, this dinosaur was originally known only by its astoundingly long 7-foot, 9-inch long arms, its shoulders, and a few ribs and vertebrae. The team decided they had a new species on their hands, and called it Deinocheirus mirificus, meaning "unusual horrible hand". Just how the arms and shoulders fit with the rest of the body was pure conjecture. In 1970, one palaeontologist argued that Deinocheirus was a giant sloth. Another throught it swam in the river, and had a paddle for a tail. Others said it was like a giant ostrich.
But a South Korean team has unearthed two nearly complete 70 million-year-old Deinocheirus skeletons in Mongolia. They also retrieved a skull and hand that had been stolen from Mongolia and sold on the black market to private collectors.
Using these finds, the researchers built the first accurate reconstruction of the dinosaur. It stood tall on its back legs and had long, clawed forearms. Neural spines formed an sail on its back, and it had a long, toothless snout flared out to both sides like a duck-billed dinosaur. Blunt, flattened bones in its feet prevented it from sinking on wet ground. It had broad hips, which meant it probably was ungainly on land, and yet had a low center of gravity which made it hard to topple over. Deinocheirus was more than 34 feet long and weighed more than 6.6 tons.
Its mouth shape indicates that Deinocheirus likely fed on plants. Fossilized fish bones were found in its stomach, indicating it probably ate small fish and amphibians, too.