 Corythosaurus was an ornithopod , and therefore a herbivore . Benson et al . ( 2012 ) realized that the beak of Corythosaurus was shallow and delicate , and concluded that it must have been used to feed upon soft vegetation . Based on the climate of the Late Cretaceous , they guessed that Corythosaurus would have been a selective <unk> , eating only the <unk> fruits and youngest leaves . Corythosaurus specimens have been preserved with its last meal in its chest cavity . Inside the cavity were remains of conifer needles , seeds , twigs , and fruits , meaning that Corythosaurus probably fed on all of these . 
