My two oldest live about 45 minutes west of Savannah, both have boats for fishing but on family outings Shark Tooth island is always on the agenda. There are other islands / beaches that give up teeth, my grandkids love looking for them, even bought them a gold panning sifter to help. My grandson found what looks like half a Meg tooth, let me see if I can find a picture.
Nice find! Looks like most of them have been there for a very long time. Because from white it became gray, black and brown. Interesting to know that the sediment prevents oxygen and destructive bacteria from reaching the tooth, and it fossilizes it!