If you look along the edge of the frill, they have these little triangular bones that actually grow big as triangles and then they flatten against the frill pretty much like the spikes do on the Pachycephalosaurs.
Si mirem al llarg de la vora del volant, tenen aquests petits ossos triangulars que creixen grans com a triangles i que acaben aplanant-se contra el volant més o menys com fan les punxes del Paquicefalosaure.