Species: mirificus OSMOLSKA & RONIEWICZ, 1970
Etymology: Latin, mirificus, 'unusual, peculiar'; in reference to the unsual structure of the fore limb.

Holotype: ZPAL MgD-I/6

Locality: Altan Ula III, Nemegt Basin, Ömnögov (South Gobi), Mongolia.

Horizon: Upper Nemegt Formation.

Biostratigraphy: Tarbosaurus bataar, Saurolophus angustirsotris and Dyoplosaurus giganteus Zone.

Age: Late Campanian or Early Maastrichtian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material: Shoulder girdle and fore limbs, fragmentary vertebrae and ribs.
Note: Palaeopathologies, left manual phalanges III-1 and III-2 bear pits, presumably from an injury to the joint between them.

Note: Tooth marks were found on the bones of Deinocheirus (BELL, CURRIE, & LEE, 2013)