 Ceratopsia or Ceratopia ( / ˌsɛrəˈtɒpsiə / or / ˌsɛrəˈtoʊpiə / ; Greek : " horned faces " ) is a group of herbivorous , beaked dinosaurs that thrived in what are now North America , Europe , and Asia , during the Cretaceous Period , although ancestral forms lived earlier , in the Jurassic . The earliest known ceratopsian , Yinlong downsi , lived between 161 @.@ 2 and 155 @.@ 7 million years ago . The last ceratopsian species , Triceratops prorsus , became extinct during the Cretaceous – Paleogene extinction event , 66 million years ago . 
 Ceratopsia or Ceratopia ( / ˌsɛrəˈtɒpsiə / or / ˌsɛrəˈtoʊpiə / ; Greek : " horned faces " ) <a href='drop_aux' title='1'><mark>is</mark></a>a group of herbivorous , beaked dinosaurs <a href='null_relcl' title='2'><mark>that</mark></a>thrived in what are now North America , Europe , and Asia , during the Cretaceous Period , although ancestral forms lived earlier , in the Jurassic . The earliest known ceratopsian , Yinlong downsi ,<a href='been_done' title='3'><mark></mark></a> lived between 161 @.@ 2 and 155 @.@ 7 million years ago . The last ceratopsian species , Triceratops prorsus ,<a href='been_done' title='4'><mark></mark></a> became extinct during the Cretaceous – Paleogene extinction event , 66 million years ago . 
Ceratopsia or Ceratopia ( / ˌsɛrəˈtɒpsiə / or / ˌsɛrəˈtoʊpiə / ; Greek : " horned faces " ) a group of herbivorous , beaked dinosaurs thrived in what are now North America , Europe , and Asia , durin da Cretaceous Period , although ancestral forms lived earlier , in tdaJurassic . The earliest known ceratopsian , Yinlong downsi , been lived between 161 @.@ 2 and 155 @.@ 7 million years ago . The last ceratopsian species , Triceratops prorsus , been became extinct during thdaretaceous – Paleogene extinction event , 66 million years ago .