hadrosaurus vs duck-billed dinosaur

hadrosaurus and duck-billed dinosaur both are nouns.

Word	Noun	Adjective	Verb	Adverb
hadrosaurus	Yes	No	No	No
duck-billed dinosaur	Yes	No	No	No

As nouns, hadrosaurus and duck-billed dinosaur are synonyms defined as:

hadrosaurus and duck-billed dinosaur: any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; may have been partly aquatic

Other synonyms of hadrosaurus include hadrosaur.

hadrosaurus (noun)	duck-billed dinosaur (noun)
any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; may have been partly aquatic	any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; may have been partly aquatic