Hans Sues, chair of the Department of Paleobiology at the Smithsonian's National Museum of Natural History, holds up a claw of a new dinosaur, Timurlengia euotica, at a news conference in Washington D.C., the United States, March 14, 2016. Scientists said Monday they have discovered the fossilized remains of a new horse-sized dinosaur that revealed how Tyrannosaurus rex (T. rex) became one of Earth's top predators about 70 to 80 million years ago. (Xinhua/Yin Bogu)