Teotihuacan's Pyramid of the Sun as seen from the Pyramid of the Moon. Image credit: Aude, Wikimedia Commons // CC BY-SA 3.0

When you see a lion, a tiger or a bear in a zoo, it’s easy to forget that people haven’t always so easily controlled big carnivores and other dangerous animals. For a long time, people were simply prey, but almost every civilization around the world has taken the upper hand over predators at some point, exploiting them for food, entertainment, and ritual uses. In ancient Egypt, crocodiles were sacrificed and mummified. On the other side of the Mediterranean, the Romans used various carnivores in gladiatorial battles and horrific "halftime" displays.

In the New World, that point has usually been fixed sometime in the 16th century, when the Aztec ruler Montezuma established a zoo in the city of Tenochtitlan. Multiple buildings and hundreds of workers were dedicated to importing, breeding, and caring for animals like wolves, jaguars, foxes, rattlesnakes, and birds of prey that served as offerings to the gods at the city’s Great Temple.

Now, a recent study published in PLOS One suggests that long before the rise of the Aztec Empire, Mesoamericans were capturing and breeding some of the region’s most intimidating predators and using them as both sacrifices and displays of power. Archaeological findings from the city of Teotihuacan push the earliest example of people keeping captive carnivores in the New World back by 1000 years.

Located 30 miles northeast of modern day Mexico City, Teotihuacan was one of Mesoamerica’s largest pre-colonial cities, home to perhaps 125,000–200,000 people. It was an important political and religious center, and the site of three large temples: the Temple of Quezalcoatl, the Pyramid of the Sun, and the Pyramid of the Moon.

During excavations of the latter two, researchers found caches of ritual offerings throughout the buildings. Among them were carved obsidian, shell and stone crafts, human sacrifices, and the remains of nearly 200 carnivorous animals, including golden eagles, pumas, jaguars, wolves, and rattlesnakes.

Sugiyama et al. in PLOS One

To learn more about the relationship between these beasts and the people who apparently kept, cared for, and ultimately killed them, a team of anthropologists led by Nawa Sugiyama of the National Museum of Natural History looked for clues about the lives of the animals in their bones. They examined 66 complete skeletons and more than 100 loose bones and found evidence that many of the animals lived in captivity. Several of the eagle skeletons, for example, all showed the same signs of stress on the inner parts of the legs, likely from being tethered to perches. Many eagle, puma, and wolf skeletons displayed fractures and bone diseases that suggested infection and injury from being kept in confined spaces and roughly handled. Some of the skeletons also had bones from other animals inside their rib cages. These turned out to belong to rabbits and hares, and many were burnt, suggesting they’d been cooked and fed to the carnivores. 

Rabbits weren’t the only thing the animals were eating. A chemical analysis of the bones revealed high levels of carbon isotopes that reflect a diet heavy in plants like maize, which these animals normally wouldn’t consume in the wild. More than half of one eagle’s diet appears to have been made up of maize and other plants.

The team also found nitrogen levels in some of the bones that reveal a grisly detail of the animals’ lives and the rituals that took place at Teotihuacan. A few of the pumas' skeletons had “exceptionally high” levels of a certain nitrogen isotope that points to the cats eating not only plants and plant-eating herbivores, but omnivores higher up on the food chain.

Line drawing of puma devouring hearts from the Tetitla apartment compound, Portico 13, Mural 3. Image credit: Sugiyama in PLOS One

These pumas, the researchers think, may have been fed meat from dogs or even humans. These meats might not have just been supplementary protein, but part of a ritual. In Teotihuacan, the researchers note there are numerous depictions of carnivores eating human hearts and even taking part in human sacrifices, dressed in military clothing and holding knives. There’s similar art at other Mesoamerican sites, and some Spanish conquistadors described the carnivores housed in Montezuma’s zoo being fed the remains of humans used in sacrificial rites.

Keeping dangerous predators as both sacrifices and as means to sacrifice humans—and being the first to do so in Mesoamerica—would have been an incredible display of power and “premier expression of state ideology and militarism” for the rulers of Teotihuacan, the researchers say. But their finds make it clear that pioneering a shift in human-predator dynamics wasn’t easy on the animals or the people.

“Specimens like the eagle attest to the hardships in learning to manipulate highly specialized carnivores,” the team writes. “Caring for and manipulating the region’s most dangerous apex predators sometimes required the use of brute force as evidenced by an unnaturally high frequency of healed fractures, violent injuries, bone deformity and disease.”