Genus: Metanothosaurus YABE & SHIKAMA, 1948 (nomen dubium)
Etymology: Greek, meta, “between, near, over” + Nothosaurus: Near Nothosaurus.

Species: nipponicus YABE & SHIKAMA, 1948 (nomen dubium)
Etymology: In reference to Japan.

Holotype:

Locality: Ishihu, near Yanaizu, Fukushima Prefecture, Honshu Island, Northeastern Japan.

Horizon: Onaqawa sandy slate.

Biostratigraphy:

Age: Spathian Stage, Upper Scythian Epoch, to lower Anisian Stage, Lower Mid Triassic Epoch, Middle Triassic.

Material: Fragmentary skeleton.