They address that part of the way down the article.
In an interview from the 1980s, Art mentioned that the University of Arizona called his find a “true American Melon” and that he had been told that it was perhaps an ancient cross of different cucurbits native to the U.S., much like the ancient cross of wild maize and teosinte that resulted in corn. This would mean that it is not a true watermelon from Africa, but a look-alike relative
I personally agree with you though. 500 plus years seems a bit too long to store viable watermelon seed, even in a dry clay jar. The seeds most likely originated from old world stock.
In an interview from the 1980s, Art mentioned that the University of Arizona called his find a “true American Melon” and that he had been told that it was perhaps an ancient cross of different cucurbits native to the U.S., much like the ancient cross of wild maize and teosinte that resulted in corn. This would mean that it is not a true watermelon from Africa, but a look-alike relative
I personally agree with you though. 500 plus years seems a bit too long to store viable watermelon seed, even in a dry clay jar. The seeds most likely originated from old world stock.