corythosaur vs hadrosaurus

corythosaur and hadrosaurus both are nouns.

Word	Noun	Adjective	Verb	Adverb
corythosaur	Yes	No	No	No
hadrosaurus	Yes	No	No	No

As nouns, hadrosaurus is a hypernym of corythosaur; that is, hadrosaurus is a word with a broader meaning than corythosaur:

corythosaur: duck-billed dinosaur with nasal passages that expand into a crest like a hollow helmet
hadrosaurus: any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; may have been partly aquatic

Other hypernyms of corythosaur include duck-billed dinosaur, hadrosaur.

corythosaur (noun)	hadrosaurus (noun)
duck-billed dinosaur with nasal passages that expand into a crest like a hollow helmet	any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; may have been partly aquatic