Holotype:

Locality: Cedar Creek anticline, Harding County, South Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material: Trackway of a theropod with tracks directly under the body.

Note: Most probably from a Chirostenotes (8 feet tall at the hips).