Tooth enamel from the skulls of 1000-year-old Mayan human sacrifices were isotopically analyzed with the goal of elucidating the provenance of the owners of those teeth. The study published in American Journal of Physical Anthropology Magazine in July of 2019 by T. Douglas Price et al. at the University of Wisconsin-Madison found that the birthplaces of the individuals varied from near their final resting places in the still waters of the Sacred Cenote (pronounced say-NO-tay) and from far across Mexico and beyond, indicating that the Mayan network extended across thousands of miles. The 60m wide natural limestone sinkhole at Chichén Itzá on the Yucatan Peninsula is a known Mayan repository for sacrifices, both human and otherwise. The historic and hallowed site was dredged at the turn of the 20th century, surrendering jade, copper, gold, textiles, pottery, weapons, other domestic objects, and the bones of over 200 men, women and children that had been offered up by the Postclassic Mayan occupants of the influential city.
The Postclassic period of Maya archeology, AD 900-1542, corresponds with a time of growth in Chichén, according to radiocarbon dating of hieroglyphics assemblages. The city likely attracted immigrants from across Mexico during its rise and period of regional dominance and may have reached a population of 50,000 inhabitants within its 300 hectare area. The city underwent regional and exotic influence as it grew in importance and size, evidenced by the architecture, ceramics, and inscriptions found at the site. Trade routes throughout the Yucatan expanded, presumably opening the city to influence from the central and southern lowlands of Mexico, parts of Central America, and along the Gulf Coast. Chichén Itzá remained a major cultural and economic center for over 200 years, after which the inhabitants seem to have disseminated, the reasons for which are unknown but conjectured to include conflict, European influence, or climate, according to previous historical studies on the area. During its fluorescence, the city was comprised of numerous temples, a marketplace called the “Court of the Thousand Columns,” two ceremonial platforms, carvings and sculptures, a major pyramid structure called “El Castillo,” and several ball courts. A raised walkway led directly, 300m (980 ft) almost due north, from El Castillo to the Sacred Cenote. Another natural sinkhole, Xtoloc Cenote, resembles an open well adjacent to the city, but did not contain offerings of any kind. It seems that all sinkholes were not created equally in the Mayan culture. Some were considered sacred, believed to be a passage to the underworld, and others were accessed for freshwater and civilian needs.
The Cenotes of the Yucatan Peninsula
The Yucatan is spotted with thousands of cenotes. The peninsula is a limestone shelf that was deposited under a rising sea. The catastrophic meteor that ended life on Earth as the dinosaurs knew it and marked the end of the Mesozoic Era reached ground zero at the northwest point of the modern day Yucatan Peninsula, very near Chichén Itzá. The Chicxulub crater is ultimately the physiographic record of the event that caused the warming trend and sea level rise over the subsequent millennia that submerged the region in a transgressive sea. The Yucatan began accumulating layers of marine limestone that culminated as one of the largest limestone platforms on Earth. The chemical composition of limestone renders it susceptible to dissolution, and when the sea level dropped again during the Ice Ages, the platform was aerially exposed. As fresh water flowed through the subsurface, it dissolved portions of the limestone, creating the cavernous cenotes, which can look like a pool, a cave, or an open well like the ones at Chichén Itzá. The cenotes are a vital lifeline to the arid region, providing freshwater to the occupants of the area where there are no above-ground rivers or lakes. Like the Mayans, modern day tourists and locals can enjoy the natural pools, explore the caves and seek spiritual enlightenment in the clear still waters and fossil-decorated limestone of the cenotes.
The Victims Preserved in the 14m Deep Waters of the Sacred Cenote Met a Grisly End
Of the 200 individuals that found their thousand-year residence in the Sacred Cenote, around half were children, the modal age being between the ages of 4 and 6. More adult males than females were found, and many subadult-aged individuals as well. The skulls and other skeletal remains were found with varying degrees of mutilation. Numerous studies have described the injuries inflicted on the people. Posthumous manipulation, disarticulation, and methods of public display have been observed. Additionally, flaying, impalement, skinning, and the like are thought to have been performed on the living individual, shortly before death. Many of the skeletons seem to have been weathered, as if displayed and exposed to the elements before cast into the waters of the sinkhole. A number of the skulls exhibited holes on either side near the temple and others with the foramen magnum enlarged at the base of the skull. The orifices were created by a percussive tool. The unnatural openings were made to display skulls on a rack of sorts that went through the sides of the heads, and others were secured at the base and openly exhibited on stakes. Whether or not these skulls were displayed as trophies, warnings, honored sacrifices or similar is up for debate, as is the frequency of the grisly practices. The remains and artifacts dredged from the Sacred Cenote are exhibited at the Peabody Museum at Harvard University and at the National Museum of Anthropology in Mexico City.
Isotopic Analysis of Tooth Enamel Elucidates the Origins of Human Sacrifices
Stable isotopic composition of strontium (Sr), oxygen (O), and carbon (C) were used to identify the birthplace of 40 individuals extracted from the Sacred Cenote. Each element, when sampled from the hydroxyapatite of tooth enamel, tells a different story about the individual, and the combined results can divulge a person’s provenance, where they were born and spent their early years. Because tooth enamel is formed during the early years of life, it records the isotopic signature found in the environment. In this study, the ratios 87Sr/86Sr, 18O/16O, and 13C/12C from the teeth were compared to the environmental data across Mexico, Honduras, and beyond. Strontium isotopes reflect regional geology and are incorporated into living organisms, local water supply and ultimately included in the cells and bones of the human body. The 87Sr/86Sr found in the carbonates of the northern lowlands near Chichén are distinguishable from the volcanics of the Guatemalan Highlands and Pacific Coast and from the metamorphic rocks of Belize and so on. Sr is an important signature in this study because it is affected by fewer processes than O and C and therefore more dependably represents provenance. O and C are both affected by numerous factors.
18O/16O is most broadly indicative of the drinking water source, with the isotopic composition being primarily controlled by temperature, the amount of precipitation, and evaporation. Here, the O isotopes primarily indicated whether the drinking water was sourced from the cold waters of the Pacific or the warmer waters of the Gulf or Caribbean Sea. 18O/16O also varied with elevation, producing a trend map across the study area that could be compared to oxygen composition of the carbonate compound in tooth enamel samples.
Lastly, 13C/12C from the apatite of tooth enamel was used as an indicator of dietary patterns of an individual’s early years. The C ratios did not vary significantly across the Mayan territory and signified the widespread reliance on maize in the population’s diet. The lack of variation therefore did not assist in specifying the birthplace of the individuals.
In conclusion, Price et al. found three main discernible locations from which the sacrifices hailed: Copan or western Honduras, Cholula or Tula of the Central Highlands in Mexico, locally across the Yucatan Peninsula. Copan was another advanced Mayan city, exhibiting the pyramidal Hieroglyphic Stairway among other elaborate Mayan sculptures and meticulously engineered structures. One adult male skull had fashionable artificial flattening on the top of his head, which, together with the isotopic data, placed him up the Gulf Coast in the lowlands or likely Veracruz, adding another locale to the map. The authors noted that there was no way to determine the timing of the sacrifices from the isotopes or other methods, so several hundred years of human offerings were treated as a single point in time. It is difficult to discern patterns in the movement of these populations, and slave-trade or capture of enemies, economic trade and voluntary migration for the religious or economic purposes are all plausible and demonstrable modes of movement at the turn of the millennium. This study lends credence to the theory that the Postclassic Mayans’ intracontinental influence reached far and wide throughout Mesoamerica.