Fundamental features of Central American civilisation first appeared between 1200 and 150 BC: stelae and monuments commemorating rulers and their reighn, the hieroglyphic writing system, a complex notation of calendrical calculations, and the ritual ball game, were all established.
Towns and cities grew, outstripping earlier farming villages. The city of Monte Albán in Oaxaca had a population of up to 16,000 in 200 BC. Such cities were governed by elite groups capable of organising huge labour forces to construct temples, palaces and pyramids.
The most famous culture of the Early-Middle-Formative period (1200 – 300 BC) in Central America is the Olmec, whose homeland lay in the wet tropical jungles of coastal Veracruz and Tabasco. The Olmec are known chiefly from their art carved in stone; few settlements have been discovered though recent excavations at Teopantecuanitlan (Tlacozotitlán), Guerrero, have revealed remains of the house belonging to the middle status family as well as preciously unknown ceremonial centre on the fringe of the Olmec world. Information comes principally from ceremonial centres such as San Lorenzo, La Venta and Tres Zapotes, where monumental basalt sculptures and small, exquisite hard stone carvings have been found in situ.
The powerful art style of the Olmecs gives a glimpse of their religion, such was dominated by a pantheon of fearsome supernatural beings, part human, part animal. The animals, which are the prototype of later Central American deities, come from the fauna of the swampy forest and coast: harpy eagles, caimans, snakes and sharks. The most frequently represented god was a were-jaguar, conceived, according to a relief at Potrero Nuevo, when a woman copulated with a jaguar. The result of this union has puffy, infantile features and a snarling mouth with downturned corners, thick lips and fangs.
The Olmec homeland was an area measuring only 200 by 50 kilometres. San Lorenzo is the oldest known Olmec centre; it flourished from 1200 BC until 900 BC, when it was destroyed. Its leading role was taken over by La Venta, located on a small island in coastal swamps.Here, a 34-metres-high clay pyramid, possibly in the shape of a fluted volcanic cone, was built, taking an estimated 800,000 working days to complete. Two plazas extended northwards from it, and rows of 3-metres-high basalt columns flanked one plaza.
The layout of the ceremonial precinct has been interpreted as a massive stylised jaguar mask, and within its limits have been found three rectangular pavements each of approximately serpentine blocks arranged to form jaguar masks. These pavements are one example of a dedicatory offering or ‘cache’ which are characteristic finds at Olmec sites.
Although the Olmecs were not a peaceful group, to judge from armed figures shown on some monuments, they were not empire builders. They established trade networks to obtain exotic raw materials such as basalt, obsidian, cinnabar, serpentine, jade and iron ore. Chalcatzingo in Morelos was probably a frontier trading station where the local populace were introduced to Olmec religion through the didactic rock-cut relief scenes. Olmec cultural influence was felt far afield – possibly even reaching Monte Albán in the Valley of Oaxaca where the Zapotecs had developed their own distinctive cultural identity and a characteristic style of monumental stone building. In Oaxaca or the Valley of Mexico Olmec influence may have been spread as much by diplomacy and marriage links as by trade, possibly strengthened by missionary activity. However, despite such evidence for widespread Olmec influence, recent archeological research indicates that the development of complex towns and ceremonialism occurred in Oaxaca, at San José Mogote, and Morelos, at Chalcatzingo, as early as and relatively independently of Olmec growth in the Gulf coast lowlands.
Like San Lorenzo five centuries before, La Venta was defaced and abandoned in 400 300 BC, and the great days of the Olmec were over. At Tres Zapotes occupation continued, but as a derivative shadow. The site has, however, produced a stela with one of the oldest dates known in the New World, a Lound Count (calendrical) inscription corresponding to 3 September 32 BC. The Gulf coast nurtured the seedlings of Mexican and Maya civilisations, establishing patterns of culture which endured for more than 2500 years.