A staff member excavates fossils from a rock in the new dinosaur and fossil hall of the Smithsonian's National Museum of Natural History in Washington D.C., the United States, on June 4, 2019. The Smithsonian's National Museum of Natural History will reopen its dinosaur and fossil hall "The David H. Koch Hall of Fossils--Deep Time" on June 8. The 31,000-square-foot exhibition will feature an authentic Tyrannosaurus rex skeleton alongside more than 700 other fossil specimens, including mammals, reptiles, plants and insects. (Xinhua/Liu Jie)