Holotype:

Locality: Dinosaur National Monument, Uintah County, Utah.

Horizon: Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone ?

Age: Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.

Material: A small nearly complete skull, and a larger partial postcranial skeleton showing paired ventral osteoscutes.