CHIAPAS.- New research into an extraordinary collection of 165 human skulls discovered inside a cave in southern Mexico is shedding light on the ritual practices of ancient Maya communities, revealing a slightly greater presence of women than men and raising new questions about the spiritual significance of these unusual deposits.

The assemblage, known as the Frontera Comalapa tzompantli, was discovered in 2012 in the Mexican state of Chiapas. Although the sight of hundreds of skulls initially presented a startling archaeological mystery, years of scientific investigation by specialists from Mexico's National Institute of Anthropology and History (INAH) are beginning to reveal a more complex picture of the people whose remains were placed inside the cavern.

According to the latest findings, researchers have identified 83 female and 79 male individuals among the 165 skulls. The sex of three individuals remains undetermined because of the fragmentary condition of their remains.

The results are particularly significant because they suggest that women may have played a more substantial role in the ancient ritual activities associated with the site than previously understood.

"Although the sample shows an apparent balance between both sexes, osteological analysis allows us to reassess the role of women in ancient ritual practices," explained archaeologist Josuhé Lozada Toledo, a researcher with INAH's Directorate of Archaeological Studies assigned to the INAH Chiapas Center.

The investigation builds on initial studies conducted by physical anthropologist Javier Montes de Paz, followed by more detailed analyses undertaken by researchers Cristell Delesma Pérez and Abigail Reyes López.

Because the assemblage does not include pelvic bones, which are generally considered the most reliable skeletal indicators for estimating biological sex, specialists examined differences in cranial morphology. These included the shape of the lower jaw and the prominence of the brow ridges, anatomical characteristics that can help distinguish male and female skeletal remains.

The research has also identified 15 children's skulls among the remains, along with cut marks on the bones of three individuals and evidence that some of the remains were exposed to heat.

Additional clues have emerged from archival photographs showing soot deposits on the cave ceiling, suggesting that ancient visitors may have entered the cavern carrying torches and conducted ceremonies within its interior.

Researchers believe these discoveries could indicate that the cave functioned as a pilgrimage destination for Maya communities, potentially hosting rituals associated with rainfall, agricultural fertility, or other ceremonial purposes.

The cave's possible sacred function is particularly important in the context of ancient Mesoamerican beliefs, in which caves frequently occupied a symbolic position in relationships between the human world, supernatural forces, and the landscape.

Mexico's Secretary of Culture, Claudia Curiel de Icaza, emphasized the importance of reconstructing the site's history through scientific investigation.

She suggested that Frontera Comalapa may have been a place of pilgrimage and ritual activity for Maya populations, adding that research can transform the initial astonishment surrounding the discovery into a deeper understanding of Chiapas' cultural heritage.

Most of the individuals represented in the assemblage were young adults between 25 and 35 years old. However, researchers also identified two individuals believed to have been between 55 and 70 years old, an unusually advanced age in the demographic context described by the investigators for the Early Postclassic Maya period, approximately AD 900–1200.

The chronology of the Frontera Comalapa deposit makes it particularly noteworthy. According to Lozada Toledo, the site predates the monumental skull-display structures associated with major central Mexican cities such as Tenochtitlan during the Late Postclassic period, AD 1200–1521.

One of the best-known examples of such structures is the Huei Tzompantli of Tenochtitlan, situated within the city's Sacred Precinct. Archaeologists have interpreted these installations in relation to ritual activity, religious beliefs, and demonstrations of political authority.

However, the Chiapas discovery raises the possibility that some skull assemblages served different ceremonial functions, reflecting local religious traditions and concepts of the human body and the afterlife.

Lozada Toledo explained that several Mesoamerican belief systems associated different spiritual essences with particular parts of the body. The teyolía was linked to the heart, the ihíyotl to the liver, and the tonalli to the head, where an individual's vital essence was believed to reside.

From this perspective, he suggested, the accumulation of skulls inside a sacred cave may have represented a gathering of spiritual essences offered to supernatural beings rather than simply a display of human remains.

The condition of the archaeological material has also provided valuable opportunities for detailed scientific study. The assemblage, currently preserved at the Physical Anthropology Laboratory of the INAH Chiapas Center, includes 165 skulls and 51 long bones, many of which remain in relatively good condition.

One particularly exceptional discovery is the preservation of a malleus, one of the tiny bones of the middle ear, belonging to an individual represented in the assemblage. Measuring only eight or nine millimeters, this delicate anatomical element rarely survives in archaeological contexts.

Other characteristics identified among the skulls include widespread evidence of intentional cranial modification, especially the tabular erect form, produced by applying boards to an individual's head during childhood.

Such practices altered the shape of the developing skull and were part of broader cultural traditions of bodily modification in ancient Mesoamerica.

The researchers also observed that most skulls lacked their lower jaws and that teeth had been removed from the upper jaws.

These modifications, together with the cut marks and indications of heating, suggest that the remains may have undergone multiple episodes of manipulation and ceremonial treatment.

According to Lozada Toledo, the evidence points toward complex rituals involving the removal, reintroduction, and rearrangement of human bones for ceremonial purposes.

The precise meaning of these practices remains under investigation, and the researchers have not established a definitive explanation for the selection of individuals or the ceremonies conducted within the cave.

Nevertheless, the findings are gradually transforming interpretations of the site, shifting attention from the dramatic appearance of the skull assemblage toward the cultural and spiritual traditions that may explain its creation.

For INAH specialists, Frontera Comalapa represents an important opportunity to reconsider the diversity of ritual practices in pre-Hispanic Mesoamerica, particularly the participation of women and the symbolic importance attached to human remains.

More than fourteen years after the cave's discovery, the continuing investigation demonstrates how careful archaeological and osteological analysis can uncover new evidence about ancient communities whose beliefs and ceremonies remain only partially understood.

The research also underscores the importance of preserving archaeological collections for future study, as new analytical approaches continue to reveal information beyond the circumstances of their original discovery.