saurischian vs dinosaur

saurischian and dinosaur both are nouns.

Word	Noun	Adjective	Verb	Adverb
saurischian	Yes	No	No	No
dinosaur	Yes	No	No	No

As nouns, dinosaur is a hypernym of saurischian; that is, dinosaur is a word with a broader meaning than saurischian:

saurischian: herbivorous or carnivorous dinosaur having a three-pronged pelvis like that of a crocodile
dinosaur: any of numerous extinct terrestrial reptiles of the Mesozoic era

saurischian (noun)	dinosaur (noun)
herbivorous or carnivorous dinosaur having a three-pronged pelvis like that of a crocodile	any of numerous extinct terrestrial reptiles of the Mesozoic era