Researcher Sun Dingwen checks dinosaur fossil samples on display at an exhibition hall of the Chongqing Museum of Natural History in Chongqing, southwest China, April 25, 2016. Dinosaur fossil researchers in Chongqing Museum of Natural History, studying in ancient vertebrate and ancient human-being, are engaged in discovering, researching on, repairing dinosaur fossils for display. (Photo: Xinhua/Qin Tingfu)
