In 1862 a colossal stone head was discovered in the state of Veracruz along the steaming Gulf Coast of Mexico. In the years to come, artifacts from the culture later termed "Olmec" turned up at widespread sites in Mexico and adjacent Central America, with the greatest number of characteristic themes being present in the region of the original discovery. For decades these findings were misinterpreted. The Maya were thought of as the "mother culture" of Mexico, and therefore the Olmecs were either insignificant or Mayan themselves, and in any case later in development.
Then in 1939 a carving was discovered near the gigantic head with a characteristic Olmec design on one side and a date symbol on the other. This revealed a shocking truth: the Olmecs had a far greater right to be considered the mother culture. Hundreds of years earlier than anyone had imagined, simple villages had given way to a complex society governed by kings and priests, with impressive ceremonial centers and artworks. Today many find the term "mother culture" misleading, but clearly the Olmecs came first.
Other megalithic heads were discovered in the intervening years, all with "African" facial features. This is not necessarily to suggest that the founders or leaders of Olmec civilization came directly from Africa, since many original populations of countries like Cambodia and the Philippines have similar characteristics. These might have been brought along when the first humans entered the Americas from Asia.
A characteristic motif of Olmec art is a human face with a jaguar mouth, sometimes called a "were-jaguar" (as in werewolf). This suggests a derivation of Olmec religion from shamanistic shape-shifting. There is evidence that the Olmecs practiced human sacrifice, including that of infants.
[Based on The Ancient Kingdoms of Mexico., by Nigel Davies, published by Penguin Books. Available in paperback and highly recommended. Also highly recommended is Michael D. Coe's paperback The Maya., published by Thames and Hudson. Coe makes the point that whether or not the Olmec is properly viewed as the "mother culture", the Maya and many other civilizations were clearly dependent on Olmec achievements.]