Species: ? alticornis (MARSH, 1887) HATCHER vide LULL, 1905/MARSH, HATCHER & LULL, 1907 (nomen dubium)
Etymology: Latin, alti, "tall, high" and Latin, cornus, "horn."
= Bison alticornis MARSH, 1887 (nomen dubium)
= Polyonax alticornis (MARSH, 1887) COPE, 1889 (nomen dubium)
= Ceratops alticornis (MARSH, 1887) MARSH, 1889 (nomen dubium)

Holotype: USNM 1817E (4739 MERRELL, 1907, USNM 4739 CARPENTER & YOUNG, 2002)

Locality: Unknown (locality 29 of CARPENTER & YOUNG, 2002), Lakewood Gulch (old Green Mountain Creek, CARPENTER, 2006), near Denver, Denver County, Colorado.

Horizon: Denver Formation.

Biostratigraphy:

Age: Lancian age, Late Maastrichtian Stage, Upper Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Horn cores.
Note: These horn cores were under Marsh's instructions to be broken and replastered to resemble those of a bison.

_____________________________________________________________________________________

Species: galeus MARSH, 1889 (nomen dubium)
Etymology: Latin, galea, "helmet."

Holotype: USNM 2410

Locality: Localty 11 of CARPENTER & YOUNG, 2002, near Brighton, Colorado.

Horizon: Arapahoe Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, Upper Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Nasal horn core.

_____________________________________________________________________________________

Species: ? eurycephalus SCHLAIKJER, 1935 (nomen dubium)
Etymology:

Holotype: MCZ 1102

Locality: Horse Creek, Goshen County, NE 1/4, sec. 4, T22N, R61W, Wyoming.

Horizon: Torrington Member, Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Fragmentary skull and fragmentary dentary and parts of skeleton.

_____________________________________________________________________________________

Species: olsoni (COBABE & FASTOVSKY, 1987) FOSTER, 1993 (nomen dubium)
Etymology: In honor of Norman Olson, on whose ranch the specimen was found.
= Ugrosaurus olsoni COBABE & FASTOVSKY, 1987 (nomen dubium)

Holotype: UCMP 128561

Locality: UCMP V83224, Norman Olson Ranch, sec. 2, T20N, R37E, Maloney Hill, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: A partial snout, including rostral pit, nasal boss, and maxillary process of the premaxillary, edentulous jaw material, an isolated vertebra; and unidentified ?skull and frill fragments.