The colorful pottery created by the ancient Paracas culture, which depicts a variety of abstract forms, people, and animals, would have perked up their drab surroundings on the southern Peruvian coastal desert more than 2,000 years ago. Now, researchers are discovering that these painted pots are also providing important—and surprising—information on the unique science behind the pigments and how connections between the Paracas culture (900-100 B.C.) and other ancient Andean cultures changed over time.

In a paper published today in the journal Antiquity, conservator Dawn Kriss worked with other experts to analyze 14 colorful Paracas ceramics from the collections of the American Museum of Natural History and the Metropolitan Museum of Art. While the time and location in which the different painted vessels were manufactured—and even the colors themselves— varied, the researchers were intrigued to learn that one constant almost always stayed the same: The plant-based binder, or the substance that held the paints together.

“We had a continuous binder being used, which means there’s a shared technology across this region and over time,” says Kriss.

While the scientists are still unable to determine what plant created the binder, they came across an unexpected and unusual ingredient in some of the pigments—reptile urine.

View Images While colors and designs in Paracas pottery varied depending on when and where it was made, researchers discovered that the binder—the substance that held the paint together—stayed consistent over time. Photographs by Dawn Kriss, courtesy of American Museum of Natural History

Tests on two light blue and white painted pottery sherds from the site of Cahuachi revealed that their pigments were completely different than those used on any of the other artifacts analyzed, and contained high amounts of uric acid.

Yes, these Paracas pigments seem to have been made with pee. And not just any old waste—when the team went looking for chemicals like the ones used on the Cahuachi sherds, they found similarities to a snake urine-based pigment used in African rock art. The Paracas team then used a sample of dried chameleon urine to verify that the Cahuachi sherds were likely intentionally mixed with reptile excrement. “That also was completely unexpected,” says Kriss.

It’s unclear how Paracas’ pottery makers enlisted reptiles in the creation of their colorful ceramics. The amount of urine production varies from reptile to reptile, and depends on a variety of factors. Some reptiles, like chameleons, produce very small amounts of urine that’s usually in semi-solid form, says Christopher V. Anderson, an assistant professor in the University of South Dakota’s department of biology and a member of the International Union for Conservation of Nature’s chameleon specialist group.

It’s also not clear if the use of reptile urine had a particular significance to the Paracas people. Kriss points out that snake motifs and even designs that may depict salamanders or chameleons can be found on some of the culture’s ceramics. “I think it’s possible it has some greater significance,” she says. But a better understanding of the role reptiles and their by-products may have played in Paracas ceramics and culture will take more investigation.

Replacing colors, changing connections

Meanwhile, the researchers also discovered that the kinds of substances used to create colors on the pots correlated with theories about the Paracas culture’s interaction with nearby civilizations. The Paracas are thought to have been influenced by the Chavín civilization (900-200 B.C.), which lived north and inland of the Paracas. Older pottery shows the use of cinnabar, a substance mined by the Chavín, but over time, cinnabar was replaced by red ochre as a pot pigment. This tracks with what historians and archaeologists think was an eventual decline of Chavín influence in Paracas culture.

View Images While up to 15 different colors can appear on Paracas ceramics, most feature a combination of four or five colors. Photographs by Dawn Kriss, courtesy of American Museum of Natural History

“We saw that shift in a variety of different pigments,” says Kriss. “It tells us a lot about the trade and interaction in this area.”

“This is very exciting research,” says Ann H. Peters, a Paracas expert and consulting scholar at the University of Pennsylvania Museum of Archaeology and Anthropology. The variability in colors, she says, also shows that Paracas potters were open to experimentation.

For now, says Kriss, she’s more interested in what the ceramics reveal about trade and cultural connections than the subtleties of reptile urine. “We still don’t know exactly what that plant binder is,” she says. “We really racked our brains. We were focusing on desert plans, but maybe it isn’t from the desert.”

If the plant binder were from an area not local to the Paracas, Kriss says, it could point to previously unknown cultural connections.

No matter what the binder, the vivid pigments of the ceramics say a lot about the Paracas, who inhabited a dull coastal desert, says Peters.

“The Paracas people learned how to create richly colored designs on their serving vessels and finest clothing” she says. “I think those colors—as well as those designs—had ritual and social power. When people gathered, they created a nucleus of brilliant color amid the drab expanses of sand.”