Photo taken on Aug. 27, 2019 shows a storage room at Naturalis Biodiversity Center in Leiden, the Netherlands. Naturalis Biodiversity Center, a renowned national museum and research institution on biodiveristy, will reopen to the public from Aug. 31, 2019 following two years of renovation and the completion of a new museum. Based in Leiden, the Netherlands, the center boasts a collection of 42 million plants, animals, fossils and rocks. (Photo by Sylvia Lederer/Xinhua)

Photo taken on Aug. 27, 2019 shows animal skeletons and other exhibits at Nauralis Biodiversity Center in Leiden, the Netherlands. Naturalis Biodiversity Center, a renowned national museum and research institution on biodiveristy, will reopen to the public from Aug. 31, 2019 following two years of renovation and the completion of a new museum. Based in Leiden, the Netherlands, the center boasts a collection of 42 million plants, animals, fossils and rocks. (Photo by Sylvia Lederer/Xinhua)

A Tyrannosaurus Rex skeleton is on display at Naturalis Biodiversity Center in Leiden, the Netherlands, Aug. 27, 2019. Naturalis Biodiversity Center, a renowned national museum and research institution on biodiveristy, will reopen to the public from Aug. 31, 2019 following two years of renovation and the completion of a new museum. Based in Leiden, the Netherlands, the center boasts a collection of 42 million plants, animals, fossils and rocks. (Photo by Sylvia Lederer/Xinhua)

Photo taken on Aug. 27, 2019 shows a new museum of Naturalis Biodiversity Center in Leiden, the Netherlands. Naturalis Biodiversity Center, a renowned national museum and research institution on biodiveristy, will reopen to the public from Aug. 31, 2019 following two years of renovation and the completion of a new museum. Based in Leiden, the Netherlands, the center boasts a collection of 42 million plants, animals, fossils and rocks. (Photo by Sylvia Lederer/Xinhua)

Visitors view exhibits at Naturalis Biodiversity Center in Leiden, the Netherlands, Aug. 27, 2019. Naturalis Biodiversity Center, a renowned national museum and research institution on biodiveristy, will reopen to the public from Aug. 31, 2019 following two years of renovation and the completion of a new museum. Based in Leiden, the Netherlands, the center boasts a collection of 42 million plants, animals, fossils and rocks. (Photo by Sylvia Lederer/Xinhua)

Visitors view dinosaur skeletons on display at Naturalis Biodiversity Center in Leiden, the Netherlands, Aug. 27, 2019. Naturalis Biodiversity Center, a renowned national museum and research institution on biodiveristy, will reopen to the public from Aug. 31, 2019 following two years of renovation and the completion of a new museum. Based in Leiden, the Netherlands, the center boasts a collection of 42 million plants, animals, fossils and rocks. (Photo by Sylvia Lederer/Xinhua)