Originally Posted by kevin
I'm not sure how closely all the writers thought about those aspects. But yeah, no clue about ridges and what that was about.
Same reasons the Klingons got ridges in TMP, to give them more of an alien appearance. Actually Unification treated the ridges as if they don't exist, otherwise Spock could have been recognized as Vulcan.
So I'd say that TNG treated the ridges as icing on the cake or to be more precise as crunching in the crisp.