Species: bullatus OSMOLSKA, RONIEWICZ, & BARSBOLD, 1972
Etymology:

Locality: Tsagan Khushu, Nemegt Basin, Ömnögov (South Gobi), Mongolia.

Horizon: Upper Nemegt Beds.

Biostratigraphy: Tarbosaurus bataar (MALEEV), Saurolophus angustirostris RHOZHDESTVENSKY and Dyoplosaurus giganteus MALEYEV zone.

Age: Lower Maastrichtian Stage, Uppermost Senonian, Uppermost Gulf Epoch, Late Cretaceous.

Referred material:

NORELL, MAKOVICKY & CURRIE, 2001

IGM 100/1133: Nearly complete but crushed skull.
Note: Interior surface of a rhamphotheca on the beek.