scaphopod vs mollusk

scaphopod and mollusk both are nouns.

Word	Noun	Adjective	Verb	Adverb
scaphopod	Yes	No	No	No
mollusk	Yes	No	No	No

As nouns, mollusk is a hypernym of scaphopod; that is, mollusk is a word with a broader meaning than scaphopod:

scaphopod: burrowing marine mollusk
mollusk: invertebrate having a soft unsegmented body usually enclosed in a shell

Other hypernyms of scaphopod include mollusc, shellfish.

scaphopod (noun)	mollusk (noun)
burrowing marine mollusk	invertebrate having a soft unsegmented body usually enclosed in a shell