Genus: Deltatheroides GREGORY & SIMPSON, 1926
Etymology: Greek, delta, triangular letter “d” and Greek, oides, : Delta (toothed) mammal-like one.

Species: cretacicus GREGORY & SIMPSON, 1926
Etymology:

Holotype: AMNH 21700

Locality: Bayan Zag (= Bayn Dzak, Shabarakh Usu GILMORE, 1943), Ömnögov (South Gobi), Mongolia.

Horizon: Djadochta Formation.

Biostratigraphy:

Age: Middle Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material: Anterior part of skull with C-M3, badly worn and broken.

Referred material:

KIELNA-JAWOROWSKA, 1975

ZPal MgM-I/29: Fragmentary left mandible with roots of canine and P1 and some what damaged P1-M4.