The tower is believed to form part of the Huey Tzompantli, a massive array of skulls that struck fear into the hearts of Spanish conquistadores when they invaded the city under Hernan Cortes in the 16th century. The severed heads of defeated warriors adorned tzompantli, or skull racks, found in a number of Mesoamerican cultures before the Spanish conquest.
What surprised the archaeologists is that the skulls forming the structure included those of women and children. This casts doubt on everything historians thought they knew about Aztec traditions.
"We were expecting just men, obviously young men, as warriors would be, and the thing about the women and children is that you'd think they wouldn't be going to war," said Rodrigo Bolanos, a biological anthropologist investigating the find.
"Something is happening that we have no record of, and this is really new, a first in the Huey Tzompantli."
The Aztecs and other Mesoamerican peoples performed ritualistic human sacrifices as offerings to the sun. Huey Tzompantli, about 6 meters in diameter, is positioned near the chapel of Huitzilopochtli, the Aztec god of the sun and war.
