With a length of 7.5 metres and a height of 2.5 metres, the Pentaceratops was the largest representative of Ceratopsidaes. Unlike the more familiar Triceratops, the Pentaceratops wore five horns on his impressive skull. All Ceratopsidae also possessed a powerful neck plate, which was probably less used for defence. The Pentaceratops probably had the largest known skull of all terrestrial animals. A real thick skull.