Photo taken on Oct. 20, 2016 shows a Tyrannosaurus Rex skeleton displayed during an exhibition at the Naturalis Biodiversity Centre in Leiden, the Netherlands. The Tyrannosaurus Rex skeleton is more than 13 meters long and 6,000 kilograms in weight. (Xinhua/Sylvia Lederer)

Photo taken on Oct. 20, 2016 shows a Tyrannosaurus Rex skeleton displayed during an exhibition at the Naturalis Biodiversity Centre in Leiden, the Netherlands. The Tyrannosaurus Rex skeleton is more than 13 meters long and 6,000 kilograms in weight. (Xinhua/Sylvia Lederer)