The latest excavation revealed a cross-shaped pit, called a cruciform, that held a cache of ceremonial artifacts, which provide unprecedented information on early Maya rituals.

The new findings were published in the journal Science Advances.

The study, Inomata said, is further evidence opposing the long-held belief that Mesoamerican cultures grew gradually, building increasingly larger settlements, such as Tikal in Guatemala and Teotihuacan in central Mexico, whose pyramid monuments are icons for Mesoamerica today. Aguada Fénix predates the heydays of those cities by nearly a thousand years—and is as large or larger than all of them.

“What we are finding is that there was a ‘big bang’ of construction at the beginning of 1,000 B.C., which really nobody knew about,” said Inomata, a researcher in the School of Anthropology, in the College of Social and Behavioral Sciences. “Huge planning and construction really happened at the very beginning.”