Source : Webster's Revised Unabridged Dictionary (1913)

Autochthonal \Au*toch"tho*nal\, Authochthonic
\Au`thoch*thon"ic\, Autochthonous \Au*toch"tho*nous\, a.
   Aboriginal; indigenous; native.

Source : WordNet®

autochthonous
     adj 1: of rocks, deposits, etc.; found where they and their
            constituents were formed [ant: {allochthonous}]
     2: originating where it is found; "the autochthonal fauna of
        Australia includes the kangaroo"; "autochthonous rocks and
        people and folktales"; "endemic folkways"; "the Ainu are
        indigenous to the northernmost islands of Japan" [syn: {autochthonal},
         {autochthonic}, {endemic}, {indigenous}]