Genus: Mei XU & NORELL, 2004
Etymology: Chinese, mei, meaning to sleep soundly.
Species: long XU & NORELL, 2004
Etymology: Chinese, long, 'dragon'; Sleeping dragon.
Holotype: IVPP V12733
Locality: Lujiatun, Shangyuan, Beipiao City, western Liaoning Province, China.
Horizon: Horizon 1, Lower part of the Yixian Formation, Jehol Group.
Biostratigraphy: Psittacosaurus Fauna, Confuciusornis Avifauna.
Age: Valanginian Stage, Upper Neocomian Subepoch, Early Early Cretaceous Epoch, Early Cretaceous.
Material: Nearly complete specimen.
Note: Has a furcula.
Note: Has its head burried below an arm, and body curled up, similar to modern birds sleeping.