Lycoptera is a genus of fish that lived from the late Jurassic to Cretaceous periods in present-day China, Korea, Mongolia and Siberia. It is known from abundant fossils representing sixteen species, which serve as important index fossil used to date geologic formations in China. Along with the genus Peipiaosteus, Lycoptera has been considered a defining member of the Jehol Biota, a prehistoric ecosystem famous for its early birds and feathered dinosaurs, which flourished for 20 million years during the Early Cretaceous.