Genus: Hyphalosaurus GAO, TANG & WANG, 1999
Species: baitaigouensis JI, JI, CHENG, YOU, LÜ & YUAN, 2004
Etymology:
Locality: Baitaigou village, northwest of the Yizhou town, Yixian County, Liaoning Province, China.
Horizon: Yixian Formation, Jehol Group.
Biostratigraphy: Psittacosaurus Fauna, Confuciusornis Avifauna.
Age: Valanginian Stage, Upper Neocomian Subepoch, Early Early Cretaceous Epoch, Early Cretaceous.
Referred material:
JI, WU & CHENG, 2010
CAGS-IB-06131: Nearly complete specimen.
Note: Has 18 embryos in the body cavity.