Travel with us down the ancient trade route that once connected the capital city of Mexico to the Atlantic coast. Sixty miles down this busy highway, lies the scene of a massacre that occurred more than 500 years ago in Zultepec — an Aztec stronghold. The remains at the site suggest these people met a gruesome end at the hands of the Aztecs, who ruled Mesoamerica in the 14th through 16th centuries — a time when priests presided over ritual killings and human sacrifice.

Forensic archaeological investigations at this ancient site have uncovered four hundred skeletal remains buried in a mass grave. It was long thought that the Aztecs did not offer significant resistance to the Spanish Conquistadors, but recent excavations strongly suggest that major fighting occurred between Aztec and Spanish forces.

There were several analyses the anthropologists carried out to obtain the answers they were looking for, including close examinations of the skulls and a series of bone measurements. The anthropologists were also able to recreate the facial features of the skulls, and thus able to find out that some of the human remains found at Zultepec belonged to Spanish Conquistadors.

Archaeologist Elizabeth Baquedano and a team of highly trained scientists spent more than 15 years piecing together the clues from the Zultepec burial site, and now you can share in their remarkable discoveries.

The Clues Uncovered

Missing Bones: The mass grave contained dismembered bodies. Vertebrae were missing from the corpses along with pelvic bones and femur bones.

Explanation: Warriors hung body parts and bones outside of their homes to attest to their bravery and success on the battlefield.

Ritual Offerings: The greatest concentration of bones was found within the southern plaza of Zultepec. Some bones were carefully laid out, while others were grouped together in seemingly random piles. The majority of the bones were buried in shallow graves close to the large temple that had once stood as the centerpiece of the town.

Explanation: There was a major religious ceremony that was crucial to the Aztecs’ way of life in obtaining the gods’ approval. This ceremony included human sacrifices. Once victims were sacrificed, their heads were hung like trophies. In preparation for display, each head was punctured through the left and right temple. More than two-dozen of these pierced skulls were found at the Zultepec site.

Unearthed Skulls: Skulls were found that did not match the body type of indigenous local tribes members captured by the Aztecs. These skulls did not fit the projected profile of a broad forehead and wide cheekbones. Skulls were found with elongated heads, and others with rounded features.

Explanation: Many of the bodies could not have belonged to the Aztec or to other local tribes. Their facial characteristics point to an entirely different ethnic and geographic origin. At least forty of the skeletons found appeared to be of European origin. Some of the skulls were more feminine than masculine. At least ten of the skulls belonged to European females.

Hidden Wombs: Archeologists found what they believed to be remains of fetuses scattered around the site.

Explanation: While there is no hard evidence that babies were stabbed in their mothers’ wombs, the scientists studied the sacrificial rituals on codices and discovered that pregnant women were sacrificed to one of the Aztec gods — and the focus of the ritual was their belly.

Zultepec is the only site in Mexico where you can uncover physical evidence of an Aztec uprising. All of the findings from Zultepec prove without doubt that at least in this one case, the Aztecs did aggressively, and successfully, resist the Conquistadors. The evidence, taken together, led the scientists to conclude that not only did the Aztecs kill Spaniards, but also they may have even consumed their bodies as part of a ceremonial ritual.