Genus: Amphidon SIMPSON, 1925
Etymology: Greek, amphi, “both, around, near”, and Greek, odon, “tooth”: Ambiguous tooth.

Species: superstes SIMPSON, 1925

Holotype: YPM 13638

Locality: Reeds YPM Quarry 9, (Mammal Quarry), T22N, R77W, Sec. 12, Como Bluff, Albany County, Wyoming.

Horizon: Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone 3.

Age: Upper Part, Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.

Material: Right mandibular ramus, alveoli for first three premolars, crowns of fourth premolar and of the four molars.