 Also the parietals are probably lacking "fenestrae" which are typical of many other genera except "Triceratops", resulting in a solid frill, although damage to the holotype allows for a small opening to be present.The first remains of "Avaceratops" were found by fossil dealer Eddie Cole in the Judith River Formation of Montana, in 1981, on land of the Careless Creek Ranch, owned by rancher Arthur J. Lammers.They were preserved scattered throughout the remains of a prehistoric stream bed.