I remember reading some time ago about the relation between these giant stone spheres and the giant heads of the olmecs. Supposedly the spheres were representative of the most popular sport at the time, a game that is still played in Mexico today...and the giants heads were those of revered ball players.As the game goes, the WINNER dies. Not much fun in that if you ask me.
The giant spheres are also representative of the small spheres found in Africa in 3 million-8 million year old strata. The smaller ones, like the much bigger ones, were rimmed around the circumference by a line, reminiscent of the 'wall' wrapped around the moon IAPETUS. Does this all tie in together? You never know.