A new genus and species, Hsiufua chaoi Zhang et Wang, is established based on a forewing from the Middle Jurassic Haifanggou Formation in Inner Mongolia, China and attributed to Campterophlebiidae, Isophlebioidea, Odonata. It is the largest odonate known in China and the fourth in the world in terms of forewing length. The maximum size (based on forewing length) of Odonata is smaller in the Permian than in the Mesozoic which is probably due to competition for prey between Odonata and Protodonata in the Permian. The reason that the maximum size of Jurassic odonates is larger than that of their extant relatives is most probably less competition and lower predation pressure from contemporary aerial vertebrates.
ZHANG HaiChunZHENG DaRanWANG BoFANG YanJARZEMBOWSKI Edmund A
