Talk about thread drift. The OP asked a question that could have been answered with a post of 4 digits and we have moved into a linguistic "chicken or egg" dialogue
. I'm putting my money on David Wilson.
David, I have jealously acknowledged that you are a statistical "nerd" so I shouldn't be surprised that you are also an erudite etymologist. My Latin consisted of three years of Caesar's Gallic Wars in high school and a graduate level course in Medical Greek and Latin in college. (That last one has been surprisingly helpful throughout my career.) Regrettably, my formal Spanish education only consists of living in Texas for the better part of a century. No matter the original derivation, the meaning of the marking is one of those things that is intuitively known.
Bob
P. S.
Re: tongue. If you haven't tried it, you should. Don't be put off by the papilla. The surface is removed and the tongue is the strongest muscle in the body and very lean. Excellent texture and taste.
B.