abstract_backgroundamargasaurusanthroayraorataobaryonyxbeakbone_frillbreastsceratopsianceratopsidchasmosaurineclawsdicraeosauriddinosaurdiplodocoidenglish_textfacial_hornfeatureless_breastsfeatureless_crotchfemalefrill_(anatomy)grouphand_on_shoulderhead_cresthi_reshornmalemarginocephalianmembrane_(anatomy)membranous_frillmusclegutmuscularnavelnose_hornornithischianpachycephalosauridpachycephalosaurusprehistoric_speciesregaliceratopsreptilesaurischiansauropodsauropodomorphscalesscaliespikesspinosauridstandingtexttheropod