MEXICO CITY.- A 17th-century codex, known as the Popotla Map, is set to undergo unprecedented scientific examination as researchers aim to unlock its secrets, including its exact origins, colonial context, and profound connections to the sacred landscape of the ancient Mexica people. This marks the first time the enigmatic document will be subjected to such rigorous analysis.

The ambitious interinstitutional and multidisciplinary project is spearheaded by anthropologist Isabel Bueno Bravo from the Center for Research and Practice in Cultural Continuity at the University of Warsaw, Poland. She is collaborating with specialists from Mexico's National Institute of Anthropology and History (INAH) and the National Autonomous University of Mexico (UNAM). The research is expected to conclude in early 2026.

Currently, the primary information available on the parchment, housed in the National Anthropology and History Library, stems from an article published in 1947 by archaeologist Alfonso Caso. The current study aims to move beyond historical analysis by employing advanced scientific and ethnohistorical techniques.

"The objective is to propose a hypothesis about its historical context, which will be confirmed or re-evaluated based on the results of the material analysis," explained Bueno Bravo. This analysis will involve micro-samples, less than five millimeters in size, taken under strict conservation protocols.

Initial insights are already emerging. María Susana Xelhuantzi López, a biologist with INAH's Archaeobotany Laboratory, noted that microscopic examination of the map's support reveals morphological characteristics consistent with goat epidermis, tentatively placing its creation in the colonial era. This hypothesis will be further tested through proteomic analyses conducted by UNAM researcher Abel Moreno Cárcamo.

Meanwhile, Alba Azucena Barrios Ruíz from INAH's Geology Laboratory, responsible for obtaining the micro-samples, observed that the pigments used on the map differ in texture from those found in pre-Hispanic codices like the Maya of Mexico. This suggests the use of industrially produced dyes rather than traditional artisanal methods. The colors identified include blue, dark green, yellow, reddish-brown, black, and light pink, and their precise nature will be investigated using various microscopy and vibrational techniques.

The document, measuring 72 by 83 centimeters, is believed by Bueno Bravo to potentially originate from a "primordial title," a legal document used by inhabitants of "Popotla" (meaning "place of the straws") to assert land rights. Its iconography, particularly the representation of caciques (chiefs), bears similarities to late 17th-century Techialoyan codices, yet much of it retains indigenous stylistic traditions. This blend suggests it could represent the early period of Spanish contact, with information possibly added at different times.

Adding to the complexity, researchers have located four copies of the map. Two are in the National Library of Austria in Vienna (both on animal skin), and two more are at the BNAH: a translucent paper tracing from 1720, known as the "Gómez de Orozco Tracing," and another on plant-based paper, possibly commissioned by Alfonso Caso in the mid-20th century.

One of the remaining enigmas to decipher is a tzompantli (skull rack) depicted in the center of the map. Bueno Bravo suggests this feature "reinforces the hypothesis that Popotla was relevant in the Mexica era, not only as one of the first settlements prior to the founding of Tenochtitlan but also as part of the empire's sacred and ceremonial landscape."

The project's ultimate goal is to establish a precise date for the map's creation, including determining the exact time of the animal's death from which the skin originated. This crucial dating will be performed by UNAM researchers Miguel Martínez Carrillo, Corina Solís Rosales, and María Rodríguez Ceja, promising to further illuminate the map's place in history.