Genus: Sinornithosaurus XU, WANG & WU, 1999
Etymology: Sinornithosaurus derived from Sin-Ornitho-Saurus, meaning
a bird-like dinosaur form China.
Species: millenii XU, WANG & WU, 1999
Etymology: Millenii derived from Millennium, Latin for one-thousand years,
referring to its discovery near the end of the twentieth century.
Holotype: IVPP V12811
Locality: Sihetun, Shangyuan, Beipaio City, Western Liaoning Province, China.
Horizon: Layer 6, Horizon 1, Lower part of the (Chaomidianzi) Yixian Formation, Jehol Group.
Biostratigraphy: Psittacosaurus Fauna, Confuciusornis Avifauna.
Age: Valanginian Stage, Upper Neocomian Subepoch, Early Early Cretaceous Epoch, Early Cretaceous.
Material: Crushed skull and fragmentary skeleton.
Note: Filamentous integument (Feathers?)
Note: Has furcula.