Child sacrifices at famed Maya site were all boys, many closely related microbiologystudy

DNA from 64 remains in the chamber pegs the bodies as males, challenging an earlier idea that females sacrificed in fertility rites were interred there, archaeogeneticist Rodrigo Barquera and colleagues report June 12 in Nature.

Boys identified in the new study ranged in age from 3 to 6, based on their tooth development. Around one-quarter had a brother or other close relative among those with analyzed DNA. Chemical analyses of diet-related substances in bones found that closely related boys had consumed similar types and proportions of foods, a sign of having grown up in the same households. Related children included two sets of identical twins.

“This is the first evidence of Maya sacrifices involving twins, which were important for Maya [beliefs about the universe],” says Barquera, of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

The sacrifices may have been for maize or rain

Reasons for the fatal ritual are unclear. But the new findings fit with prior suggestions that the underground space contains children sacrificed to ensure the growth of maize crops or to appease the Maya rain deity Chaac, the researchers say.

While Barquera and colleagues regard the burial chamber as a repurposed underground cistern for storing water, archaeologist James Brady of California State University, Los Angeles says it was constructed as an artificial cave. Ancient Maya people created large numbers of artificial caves for a range of spiritual purposes, Brady notes; he examined the chamber in 2017 and 2018 (SN: 5/15/02).

Barquera’s team suspects that closely related boys were chosen for ritual sacrifices as stand-ins for powerful mythological figures known as the Hero Twins. A Maya document written in the 1550s, the Popol Vuh, recounts tales of the Hero Twins avenging the murders of their father and uncle (also twins) by underworld gods. After a series of sacrificial deaths, the Hero Twins came back to life to outwit those same deities.

Radiocarbon dating of bones from the underground chamber indicates that boys were ritually interred from around 500 A.D. to 900 A.D., Barquera’s group reports. The team cannot say for certain whether the ancient Maya placed bodies there one at a time over decades and centuries, or if sacrificed children were buried in pairs or larger sets.

There are echoes of modern rain rituals

Barquera’s findings “bring to mind ancestral Yucatec rain invocation ceremonies that are still practiced among traditional Maya communities, especially during times of drought,” says Vera Tiesler, a bioarchaeologist at the Autonomous University of Yucatán in Mérida, Mexico, who did not participate in the new study. In that context, Barquera’s scenario of agriculturally related sacrifices of closely related boys associated with the Hero Twins is plausible, she says.

But too little is known about ancient Maya rituals at Chichén Itzá to conclude that sacrificed male twins had anything to do with the Hero Twins story, says bioanthropologist Cristina Verdugo of the University of California, Santa Cruz.

During modern Cha-Chaac rites, boys sit beneath or are tied to an altar adorned with vegetation. The youngsters, no longer ritually sacrificed, imitate sounds of the four winds, frogs or other noises linked to first rains, aiming to invoke the cooperation of the rain god Chaac.

Previous Chichén Itzá researchers described a type of flute called an ocarina that lay among human remains in the underground chamber, Tiesler says. That instrument could have been used to produce rain-relevant sounds, she speculates.

The sex of the deity may determine the sex of those sacrificed

The DNA findings at Chichén Itzá fit with emerging evidence that, at least at some ancient Mexican and Central American sites, the sex of the deity to whom sacrifices were made determined the sex of those chosen as offerings, Verdugo says. The male rain god Chaac possibly motivated sacrifices of young boys at Chichén Itzá.

At an Aztec site in Mexico, other researchers have reported that a temple dedicated to the male rain god Tlaloc contained a burial place for ritually sacrificed boys. And preliminary genetic investigations, directed by Verdugo, at Midnight Terror Cave in Belize have found that four sacrificed youngsters assessed so far — out of at least 55 interred there between around A.D. 550 and A.D. 900 — are female (SN: 4/19/16).

Those four are not a lot to go on, but historical accounts describe Maya sacrifices of females divided into young and middle-aged groups meant to represent goddesses in those two age groups, Verdugo says. Further DNA work at the Belize cave will test whether sacrificed children and at least 12 adults found there represent two groups of females.

What is clear, Barquera says, is that ritual sacrifices differed in various ways across many ancient Maya sites and even within the same sites.

Aside from the sacrificial burial chamber at Chichén Itzá, more than 200 sacrificed individuals found in a large sinkhole known as the Sacred Cenote included males and females ranging in age from children to adults. Tiesler and colleagues have reported that many of those people came from as far away as Central Mexico and Central America, perhaps as part of groups involved in long-distance trading.

Reliefs and murals in the Sacred Cenote, as well as skeletal evidence, indicate that sacrificial rituals included removing heads and other body parts for public display, Tiesler says.