Deinocheirus Arms at AMNH

The first parts of the dinosaur Deinocheirus to be found were a pair of long clawed arms dug out of the Nemegt Formation in Mongolia, lending the dinosaur its name, Greek for "terrible hand."  Until more fossils were found, scientists could not accurately classify Deinocheirus, but it is now considered a large ornithomimosaur with two relatives, Garudamimus and Beishanlong.  This cast of the arms of Deinocheirus is displayed at the American Museum of Natural History.