triceratops horridus skeleton. triceratops is an extinct genus of herbivorous ceratopsid dinosaur which lived during the late maastrichtian stage of the late cretaceous period, around 68 to 65 million years ago in what is now north america. bearing a large bony frill and three horns on its large four-legged body, triceratops is one of the most recognizable of all dinosaurs. royal tyrrell museum, alta, canada