Species: ? bexelli (BOHLIN, 1953) OLSHEVSKY, 1978 (nomen dubium)
Etymology:
= Troodon bexelli BOHLIN, 1953 (nomen dubium)
= Stegoceras bexelli (BOHLIN, 1953) KUHN, 1964 (nomen dubium)

Holotype:

Locality: Tsondolein-khuduk, Ordos (Shaan-Gan-Ning) Basin, Inner Mongolia (Nei Mongolia), China.

Horizon: Tsondolein Khuduk Beds.

Biostratigraphy:

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

Material: Fragmentary parietal.

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Species: gilmorei MARYANSKA & OSMOLSKA, 1974
Etymology: In honor of Charles W. Gilmore, who first gave the detailed description of a pachycephalosaurid species.

Holotype: Z. Pal. No. MgD-I/105

Locality: Khulsan, Nemegt basin, Ömnögov (South Gobi), Mongolia.

Horizon: Barun Goyot Formation.

Biostratigraphy: Djadochtatherium catopsaloides KIELAN-JAWOROWSKA, Nemegtbaatar gobiensis KIELAN-JAWOROWSKA, and Chulsanbaatar vulgairs KIELAN-JAWOROWSKA Zone.

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

Material: Damaged skull with several maxillary teeth, lacking braincase, palate and anterior portion of snout, mandible with several mandibular teeth, lacking anterior portion of dentary, as well as articular and prearticular.