Deinocheirus, meaning “terrible hand”, is a genus of theropod dinosaur from the Late Cretaceous Period that lived in what is now southern Mongolia. It was named by Halszka OsmÃ³lska and Ewa Roniewicz in 1970. The only species known is D. mirificus. Replicas of the fossilized arms are on display in museums in Oslo, Norway, and in New York, and Utah, United States.
The only remains recovered are a single pair of massive forelimbs that measure 8 feet long, with 10 inch claws. A few ribs and vertebrae were also found. Based on the size of the arms, it is estimated that the animal would have weighed as much as 10 tons (20,000 pounds), making it one of the largest theropods to have ever lived.
It is assumed it would have used its long, massive forelimbs for tearing apart dead prey. The clawed hands could have been deadly weapons for attacking dinosaurs of almost any size, and easily being able to rip open the soft bellies of sauropods. Others disagree, stating that the claws were too blunt to be effective killing weapons, but may have been better used for defense. Other studies suggest that the claws were used as special tools for climbing, and that it fed mostly on fruit, leaves, eggs, and possibly smaller animals found in trees. Most scientists disregard the theory that Deinocheirus was a climbing dinosaur based on its huge size.