Holotype:

Locality: Bone Cabin Quarry, 8 miles north of Como, Medicine Bow Anticline (also called Flat top Anticline), Albany County, Wyoming.

Horizon: Salt Wash Member, Morrison Formation.

Biostratigraphy: Zone 2.

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

Material: Skull and fragmentary skeleton.