Coca leaves found in three young llamas’ wool at a Peruvian Inca site are the first direct evidence of coca in a ritual at that site

Fragments of coca leaf were still caught in the wool of three young llamas that were sacrificed at Tambo Viejo, a fortified site in Peru’s Acarí Valley. The leaves, preserved for roughly 550 years, are the first direct evidence of coca used in a ritual at the site, and the llamas themselves were dressed for the occasion with tassels and red paint on their faces.

University of Calgary archaeologist Lidio Valdez, whose team has excavated at Tambo Viejo since 2018, reported the find with Katrina Bettcher and M. Soledad Gutiérrez in the journal Ñawpa Pacha. Radiocarbon dating places the offerings between AD 1450 and 1500.

Three of nine llamas in Structure 4

The leaves came from a deposit under the floor of Structure 4, which Valdez’s team excavated in 2024. According to Archaeology News, coca was caught in the wool of three of the nine young llamas in the deposit. The animals were arranged as a ceremonial offering, their legs folded and tied, then covered with river sand. Four guinea pigs were laid on top, a fire was lit, and the whole deposit was sealed under a clay floor.

According to the same report, the offerings predate the earliest buildings in that part of the settlement.

Gizmodo’s account of the paper adds that fragments also lay on the back necks of sacrificed llamas, that the animals show minimal signs of physical trauma, and that the team has so far found 14 llamas at the site. It reports that the evidence, which contradicts colonial-era descriptions of the Inca burning guinea pig offerings, suggests the animals were likely buried alive. On motive, Valdez was candid, saying the reasons for the sacrifices may never be known.

Nine of the 14 llamas found at the site were packed into one corner of Structure 4, the Gizmodo report says, and the same account notes that naturally mummified guinea pigs have turned up only at Tambo Viejo, with nothing similar reported from other Inca settlements. Separate guinea pig sacrifices lay with a hearth in Structure 1.

Priority claim: this site or any ritual

The priority claim depends on where the sentence stops. Earth.com’s report calls the leaves the first direct evidence of coca in a ritual at the site, and a Spanish-language report by Infobae, citing Phys.org, uses the same wording, with a photo caption crediting Valdez and colleagues that reads “the first direct evidence of this type identified at the site.”

Valdez himself is reported to go further. Archaeology Magazine says coca leaves and seeds had been unearthed before in storage areas at Peruvian archaeological sites, and quotes Valdez saying this is the first time they have been found in a ritual context. Earlier digs at Tambo Viejo had recovered coca seeds and a few leaves from a storage building, which implied the plant grew nearby but said nothing about ceremony.

Coca as a sacred plant, and a paper on Inka rituals

Colonial writers had already described coca in Inca ceremony, and Infobae notes that the Tambo Viejo leaves are presented as the first material record of that use. Until now the practice rested on written accounts alone. Valdez told Phys.org, as Earth.com quotes him, “Above all, coca was a sacred plant to the Inkas.” Spanish written records, he said, show it was used in almost every ritual activity, which is why he had been looking for it at the site for some time before it finally turned up. He is also skeptical of those colonial accounts, saying the chroniclers recorded only what they were told, and he doubted the Inca told them everything accurately, according to Infobae.

Valdez has imagined how the scene looked: the llamas paraded in procession through the main plaza, with ritual leaders giving speeches to those gathered. Archaeology Magazine presents that picture as his speculation, not a documented finding.

Bettcher and Gutiérrez are credited as co-authors alongside Valdez by Archaeology News. The paper is listed by the publisher as Coca Leaves in Inka Rituals in Tambo Viejo, Acarí Valley, Peru, in volume 46, issue 2 of Ñawpa Pacha.

An earlier set of llama offerings

Tambo Viejo has produced llama sacrifices before. A 2020 report on llama offerings excavated in 2018, published in Antiquity by Valdez and colleagues, described young llamas buried under the floors of two buildings, with decorated guinea pigs, feathers and food offerings alongside. Charcoal from those burials was radiocarbon dated to 1432 to 1459, which suggested the Inca took the Acarí Valley decades before the 1476 date previously believed.

The 2026 offerings, dated to AD 1450 to 1500, add a plant to that list for the first time at the site. None of the reports read says where the coca was grown or how long it was kept before it was placed on the animals, so its source remains an open question for the team.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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