This time frame is referred to as the Late Olmec Period of southern Mexico, which featured pyramids for the first time in ceremonial centers. La Venta, the 2nd major Olmec capital dates to this period. (aug 3, 900 BC – aug 3, 500 BC)
Added to timeline:
Date:
aug 3, 900 BC
aug 3, 500 BC
~ 400 years