Genus: Koshisaurus SHIBATA & AZUMA, 2015
Etymology: The generic name consists of 'Koshi', the name of the ancient state in the 7th centruy, 'Koshi no kuni', in the southern part of which is now the Fukui Prefecture, Japan and Greek, sauros, "lizard."

Species: katsuyama SHIBATA & AZUMA, 2015
Etymology: In reference to the Katsuyama city where the described material as found, Fukui Prefecture, Honshu Island, Japan.

Hootype: FPDM-V9079

Locality: Kitadani Locality (Dinosaur Quarry), on the Sugiyama River, northern part of the city of Katsuyama, 36°7’N, 136°33’E, Fukui Prefecture, Honshu Island, Japan.

Horizon: Kitadani Formation, Akaiwa Subgroup, Tetori Group.

Biostratigraphy:

Age: Barremianstage, Lower Gallic Subepoch, Early Cretaceous Epoch, Early Cretaceous.

Material: Right maxilla.

Referred material:

FPDM-V9077: Distal part of a left femur.

FPDM-V9078: Neural arch and axis.

FPDM-V9080: Proximal portion of left pubis.

FPDM-V9091: Centrum of the caudal-most dorsal vertebra.