Species: cretacea ESTES, 1969
Etymology: In reference to the Creaceous period.

Holotype: MCZ 3504

Locality: Bug Creek Anthills (BCA), 80 feet below the Tullock Formation in the west half of Section 9, T22N, R43E, McCone County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material: Vertebra.

Paratypes:

MCZ 3506-3509, 3627-3636: Vertebrae.

MCZ 3505, 3637: Atlantes.