In a vacant corner of the cemetery, Davila is at work on another problem: the Huasteca's muddled chronology. Datable carbon has proven scarce in the Huasteca; the most authoritative timeline is almost seventy years old, a ceramic sequence completed by American archaeologist Gordon Ekholm. Davila is in pursuit of a more accurate history, built with both pot sherds and elusive carbon-14, that will help explain who lived here, and why and when they left.
He sits in a low chair, guiding laborers who dig a neat pit and tape-measure the dimensions of the exposed layers. “The dates of the early cultures of the Huasteca are terribly bad,” he says, so researchers lump disparate cultures together. “It's like if you say in the Valley of Mexico: the Aztecs for Cuicuilco, the Aztecs for Tlatilco, the Aztecs for Teotihuacán. It is the same for the Huastecs - many cultures are put in the same basket. Its not clear researchers understand the situation.”
The abrupt end of the area’s successive occupations might have been due to the Tampaón River's periodic floods, catastrophic inundations that turn the floodplain into a gigantic miles-wide lagoon that submerges today’s local towns to their rooflines. Changing climate, too, may have played a role. In the seventh century this region became part of a semi-desert that extended to present-day Texas. The locals moved northwest to the flourishing city of Teotihuacán or to El Tajín to the south where rain was plentiful. But after Teotihucán fell in about AD 750 and the weather improved, the Huasteca revived.
“The region attracted many people from many places,” Davila says. They included groups from the west and northwest; Maya-influenced Nahua who had first gone to the north of the Yucatan peninsula; and Maya who came north from the what is now the Chiapas-Guatemala border area, speaking a tongue that evolved into the language spoken today by their descendants, the Huasteca's Teenek people. The influx bequeathed the Huasteca a rich ethnic mix, but today's diversity is a shadow of the pre-Conquest population’s, when the Huasteca was home to as many as twelve distinct cultures.
Davila and Zaragoza know they have only begun to tell the region’s story. They've started crisscrossing the Huasteca, pushing into tangled scrub forests and tick-infested thickets in search of long lost settlements. Within sixty miles of the Tampaón they've found unexcavated sites that dwarf Tamohi, with monumental structures built in puzzling architectural styles found nowhere else. The pair think most date to after 1350. Shrouded in centuries of riotous growth, untouched by looters, they remain unexplored by archaeologists, save for Davila and Zaragoza, who lead the way.