autochthonal vs autochthonic

autochthonal and autochthonic both are adjectives.

Word	Noun	Adjective	Verb	Adverb
autochthonal	No	Yes	No	No
autochthonic	No	Yes	No	No

As adjectives, autochthonal and autochthonic are synonyms defined as:

Other synonyms of autochthonal include autochthonous, endemic, indigenous.

autochthonal (adjective)	autochthonic (adjective)
originating where it is found	originating where it is found