MEXICO CITY.- Ten years ago, archaeologists in Mexico City made a startling discovery: the Huei Tzompantli, a massive Aztec skull rack, buried beneath the modern capital. Now, a decade later, the skulls from this incredible find are revealing their secrets through cutting-edge science.

For the first time, researchers are using advanced techniques like stable isotope and ancient DNA analysis to understand the lives of the individuals whose remains were part of this sacred structure. Instead of just seeing the skulls as a macabre monument, scientists are approaching them as people—asking where they were born, what they ate, and what their genetic history was.

"We want to know where these people were born," explained anthropologist Jorge Gómez-Valdés, whose team is analyzing samples from 83 skulls at the University of Georgia in the United States. By studying isotopes in the teeth, which form in early childhood, they can pinpoint the geographic origins of the individuals, offering new clues about who the Aztecs chose for this ritualistic purpose.

The project, a joint effort by Mexico's National Institute of Anthropology and History (INAH) and international partners, is also sending samples to the renowned Max Planck Institute in Germany for DNA analysis. This work will help determine the sex of incomplete remains and shed light on ancient family lineages.

The discovery and preservation of the Huei Tzompantli has been a monumental undertaking. The structure, unlike any other found in Europe or elsewhere, was built with skulls as the primary construction material. Archaeologists and conservators have meticulously worked to stabilize the remains, documenting over 11,000 fragments and ensuring the fragile history is preserved for future generations.

The research has already yielded some surprising findings. The skulls are remarkably well-preserved, with no signs of animal interference. Initial analysis also shows a diverse population, with both men and women represented in the monumental skull tower—a detail that challenges some previous historical assumptions about the Aztec practice. This research is just the beginning, but it's already helping to transform our understanding of a powerful and complex ancient civilization.