noun. Any of various herbivorous ornithischian dinosaurs of the family Hadrosauridae of the Cretaceous Period, having a broad toothless beak, numerous teeth in the back of the jaw, a stiff tail, and sometimes a crest on the head.

noun. One of the Hadrosauridæ.

noun. Any of the family Hadrosauridae of duck-billed dinosaurs; a hadrosaur.

"In the photo above, Luis is holding a caudal vertebra from a hadrosaurid that bears a deep score mark across its surface."