Genus: Yamatosaurus KOBAYASHI, TAKASAKI, KUBOTA & FIORILLO, 2021
Etymology: In reference to the ancient name for a region of the Japanese archipelago, "Yamato", including the western half of the main island (Honshu Island), Shikoku Island, and the northern half of Kyushu Island, ruled by the Yamato Kingdom from the third to the seventh century, and Greek, sauros, "lizard."

Species: izanagii KOBAYASHI, TAKASAKI, KUBOTA & FIORILLO, 2021
Etymology: In reference to the Japanese mythology deity, which created eight countries of Yamato with another deity, Izanami, based on the oldest history book in Japan called "Kojiki (records of Ancient Matters)", published in 712 CE (Common Ear). The first country created was the Awaji Island, followed by the Shikoku, Oki, Kyushu, Iki, Tsushima, Sado, and Honshu Islands.

Holotype: MNHAH D1-033516

Locality: Locality Aw14 (Morozumi) of Yura Town, Sumoto City, Awaji Island, Hyogo Prefecture, Honshu Island, Japan.

Horizon: Kita-ama Formation, Izumi Group.

Biostratigraphy:

Age: Early Maastrichtian Stage, Late Senonian subepoch, Late Gulf epoch, Late Cretaceous.

Material: A right dentary, a right surangular, 12 isolated dentary teeth, 4 cervical vertebrae, a distal caudal vertebra, 3 cervical ribs, and a coracoid.