The holotype specimen, AMNH 3978, was described by paleontologist and naturalist Edward Drinker Cope, who interpreted it as the rostral bone and predentary of an "agathaumid" (ceratopsid)  dinosaur, which he said came from the Laramie Formation of Colorado. It was soon thought to be a hadrosaurid, though.
The holotype specimen, AMNH 3978, was described by paleontologist and naturalist Edward Drinker Cope, who interpreted it as the rostral bone and predentary of an "agathaumid" (ceratopsid) dinosaur, which he said came from the Laramie Formation of Colorado. It was soon thought to be a hadrosaurid, though.