Introduction to the Liaoxi Fossil Exhibition Hall: The Mesozoic "Rehe Biota" animal and plant fossils produced in western Liaoning, China, cover almost all terrestrial biological categories of the Mesozoic, especially mammals, ancient birds, and hairy dinosaurs. , frogs and angiosperm fossils, etc., have helped mankind solve many unresolved problems in the history of biological evolution. One of the nests of Psittacosaurus fossils is by far the only, largest, most complete, and shocking national treasure fossil specimen in the world. It can be called a national treasure.