Genus: Nipponosaurus NAGAO, 1936
Etymology: In reference to Japan, from Nippon, and Greek, sauros, “lizard”: “Japanese lizard”.

Species: sachaliensis NAGAO, 1936
Etymology:

Holotype: Institute of Geology and Mineralogy, Hokkaido Imperial University, Regist, No. 6590

Locality: Sachalinskaya Oblast, Sachalin Island, Asian Russia (Old Kawakami Colliery, Toyohara-gun, Island north of Japan).

Horizon: Mh7 or Mh6 of Miho Group, Upper Ammonites Beds.

Biostratigraphy:

Age: Early Santonian or Late Coniacian Stage, Lower Senonian Subepoch, Lower Gulf Epoch, Upper Cretaceous.
Note: Upper Santonian-Lower Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous, MATSUKAWA & OBATA, 1994.

Material: Fragmentary skull and fragmentary skeleton.
Note: Paleopathology? MT III has an unusual development (BRETT-SURMAN, 1989)