Species: simpsoni FOX, 1984
Etymology: In honor of George Gaylord Simpson, for the contributions to our
understanding of Mesozoic Mammals.
Holotype: UAMR-20
Locality: Verdigris Coulee, approximately 29 km (18 miles) east of the town Milk River, Warner County, Alberta Province, Canada.
Horizon: Upper Milk River Formation.
Biostratigraphy:
Age: Aquilian age, Lower Campanian Stage, Aquilian in age, Senonian subepoch, Upper Gulf epoch, Late Cretaceous.
Material: Upper left molar.