fossil vs wormcast

fossil and wormcast both are nouns.

Word	Noun	Adjective	Verb	Adverb
fossil	Yes	Yes	No	No
wormcast	Yes	No	No	No

As nouns, wormcast is a hyponym of fossil; that is, wormcast is a word with a more specific, narrower meaning than fossil:

fossil: the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil
wormcast: fossil trail of a worm

Other hyponyms of fossil include fucoid, belemnite, ammonite, ammonoid, guide fossil, index fossil, microfossil.

fossil (noun)	wormcast (noun)
the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil	fossil trail of a worm
someone whose style is out of fashion	cylindrical mass of earth voided by a burrowing earthworm or lugworm

fossil (adjective)	wormcast (adjective)
characteristic of a fossil