Female Skeletons Identified as Nobles found in Cahokia's 'Beaded Burial' Mound 72.

From about 800 to 1350 AD, Cahokia was apparently one of the biggest cities in the world. At its height, it had 20,000 residents. The complex society at Cahokia, part of the Mississippian Culture, prospered in the fertile lands off of the Mississippi Valley across the river from modern St. Louis, Missouri.

In the ruins of the ancient city of Cahokia, which flourished hundreds of years ago, there is a burial mound with the remains of a royal or noble couple. Buried around them in the mound are the skeletons of many people who were brutally chopped up, strangled or bled to death in apparent sacrifices.

Burial Mound 72 is called the “beaded burial” because two of the bodies at the center of the grave contained two bodies on a bed of luxurious beads, but it was previously thought to contain the bodies of six highly important men. A new study concludes that some of the 12—not six—high-status skeletons include women and one child. Buried at the very center of this central beaded burial feature is the couple—that is, a man and woman. The burial mound was used from about 1000 to 1200 AD.

“The fact that these high-status burials included women changes the meaning of the beaded burial feature,” archaeologist Thomas Emerson of the Illinois State Archaeological Survey said. “Now, we realize, we don’t have a system in which males are these dominant figures and females are playing bit parts. And so, what we have at Cahokia is very much a nobility. It’s not a male nobility. It’s males and females, and their relationships are very important.”

Inside the burial mound, rediscovered in 1967 by archaeologist Melvin Fowler, were five mass graves with between 20 to more than 50 bodies. Many of them were sacrificed.

This graphic shows the arrangement of the beaded burial, which had a man and woman, not just two men as was previously believed.

Mound 72 burials are some of the most significant burials ever excavated in North America from this time period. Fowler’s and others’ interpretation of these mounds became the model that everybody was looking at in terms of understanding status and gender roles and symbolism among the indigenous people groups in the 1960s era.

Recent research says that Fowler and other researchers erroneously concluded the beaded burial was of two high-status men who were buried with their servants. They thought the beaded cape or blanket was in the shape of a bird, which are symbolic to warrior societies and mythology in the Indian culture. So Fowler concluded that the beaded burial was of two male warrior chiefs. Researchers extrapolated these conclusions to surmise that Cahokia had a “male-dominated hierarchy.”

A fresh look at the early archaeologists’ maps, notes and reports, and the skeletal remains told a new and surprising story. First, the researchers found that there were 12 bodies associated with the beaded burial – not six, as had been previously reported. And independent skeletal analyses revealed that the two central bodies in the beaded burial were actually male and female. Further analyses revealed other male-female pairs on top of, and near, the beaded area. Some were laid out as fully articulated bodies. Others were disarticulated bodies, the bones of which had been gathered and bundled for burial near these important couples. The researchers also discovered the remains of a child.

Mound 72 at Cahokia held several mass graves but also burials of high-status individuals, some of which included items like these artifacts. Pictured here are chunky stones likely used in games, Cahokia-style tri-notched projectile points, and marine shell disc beads like those used in the beaded burial at Cahokia.

Researchers had speculated that victims of human sacrifice found at Cahokia were brought in from outside the area, perhaps as a tribute. But an analysis of the element strontium (is a trace element found in seawater and soil and is similar to calcium, with the symbol Sr and atomic number 38, its an alkaline earth metal) in the victims’ teeth shows they were mainly local -- especially the 39 people brutally killed and unceremoniously dumped in a mass grave.

Strontium is absorbed into the human body from the underlying bedrock through the consumption of local animals and plants. Since the levels of strontium vary across the midcontinent depending on the local geology the level of strontium absorbed by individuals also varies. Investigations of the strontium levels of the remains of individuals who died at Cahokia between 900 AD and 1350 AD indicate that fully one-third of these people were foreigners from outside the immediate vicinity of Cahokia. This suggests that Cahokia could not rely on traditional kin-based political and social models but likely had to “invent” new ways of social and political control and population management.

Mound 72 had groups of people, some of the victims of sacrifice, buried in large pits. Many were laid out in neat rows and had little sign of trauma. Researchers speculate they died of strangulation or blood-letting.

Compiled by Neil Gale, Ph.D. 

Did Megafloods spell the end of the Ancient City of Cahokia?

The mysterious demise of the ancient city of Cahokia has long remained unexplained. Still, recent research suggests catastrophic megafloods may have devastated crops and food stores and forced residents to suddenly abandon their city some 700 years ago.

A reconstruction of Cahokia with Monks Mound in the distance.

Once North America's largest and most sophisticated cultural center north of Mexico, the ancient city of Cahokia, located in present-day Southern Illinois, was an economic powerhouse at its height from about 1000 to 1150 AD. Its sphere of political and religious influence extended from the Great Lakes to the Gulf of Mexico. The city was home to approximately 20,000 people, and it sprawled over 6 square miles, boasting 120 man-made mounds — the largest of which was 10 stories or 100 feet in height, and its footprint covered 14 acres or 610,000 square feet. Known as Monks Mound, it was the largest prehistoric earthwork in the Americas. The building of the mound was a massive undertaking, requiring an estimated 79,000 square feet of earth. 

Samuel Munoz, a geographer at the University of Wisconsin-Madison, has spent several years researching how Cahokia's residents shaped the local landscape, such as how farming affected the region. During this research, he discovered the buried remains of a massive flood dated that likely destroyed the crops and houses of more than 15,000 people. Evidence for the flood is a silty deep core sediment layer nearly 8 inches thick, dated to 1200 AD, +/- 80 years. Although Cahokia wasn't completely abandoned until 1350 AD, Munoz had been able to show that the area experienced periods of severe flooding as the climate changed over the centuries. The catastrophic flood would have shaken the city's confidence, eventually leading them to decide to move on, and the inhabitants never returned.

Beginning of the End
The exact reasons behind the city's decline have long been debated by scientists. Various theories include political battles, crop failures, climate change, and an epic fire. However, Munoz and colleagues established the timing and severity of the historical flood patterns in the area.

A display depicting everyday life in the once-thriving ancient metropolis at the Interpretive Center at Cahokia Mounds.

Cahokia's decline coincided with a major Mississippi River surge around 1200 AD. The sediment core samples contained almost no charcoal, pollen, or plant matter fossils and were made of silty clay, much like floodwater sediments. This indicated a period of flooding. However, the layers above and below the clay contained telltale markers of aridity, such as plant material and charcoal. Researchers were able to date the various samples and create a timeline of events.

Megafloods
Munoz described the cycle that doomed the city of Cahokia: "Beginning around 600 AD, high-magnitude floods became less frequent, and indigenous peoples moved into the floodplain and began to farm more intensively and increased their numbers."

Around 1200 AD, +/- 80 years, the North American climate became wetter, and the waters rose, flooding the area with severe and frequent deluges. Crops would have suffered, food stores were probably ruined, and the population would have had to relocate or starve. Floodwaters thought to have risen 33 feet above base elevation, would have jarred a population unprepared for such environmental challenges. After hundreds of years without large floods, it would have had a particularly destabilizing effect.

Archaeologist George Milner at Pennsylvania State University found the analysis convincing but suggested that megafloods might have been only one of many catastrophes that eventually led to Cahokia's downfall, including droughts, fires, cold and hot years -- all leading to social instability. The real problem starts when indigenous people experience back-to-back failures.

The findings by Munoz and colleagues may have finally solved the mystery of the abandoned city of Cahokia and potentially given us a glimpse into what the future might hold for the flood-prone Mississippi Valley region.

Compiled by Dr. Neil Gale, Ph.D.