Introduction to Jehol Fish Hall: Jehol Fish Hall displays many very precious fish fossils. Fish first appeared in the Cambrian period. From the Mesozoic era, bony fish gradually became more prosperous than cartilaginous fish until now. There are Chinese sturgeon, Chinese bowfin fish, scale-toothed fish, etc. There are also large fish plate fossils of more than 100,000 wolf-finned fishes.