Latitudinal range: 41.5° to 41.9°

Found in two samples

United States: Fossil Butte (FB-16) (Early Eocene), Cooper Creek (Early Eocene)

See also Esthonyx, Esthonyx acutidens, Esthonyx ancylion, Esthonyx grangeri, Esthonyx gunnelli, Esthonyx sp., Esthonyx spatularius