I have yet to find any writings on it tho'....and very few will discuss it. It was implied once that, that is where the saying, "black like a Mexican" was in reference to...the african heritage.
when reading up on the olmecs, while the documention says the sculptures left behind have african characteristics...they are quick to say that it does not mean it was african in origin but that asians from islands like the phillipines have similiar characteristics.
also, when searchin on the net for black sailors/explorers/seamen.....i find info dating back to the civil war.
nothing on the africans living on the coasts of the continent.