PALOS VERDES.- Archaeologists in the northern Mexican state of Sinaloa have made a significant discovery, unearthing two pre-Hispanic crematoria and an ossuary that are shedding new light on the ancient funerary practices of the Guasave people. The findings, made in the community of Palos Verdes, are part of the ongoing Guasave Archaeological Project.

Led by archaeologist Rodrigo Vivero Miranda and endorsed by Mexico's National Institute of Anthropology and History (INAH), the recent field season revealed funerary contexts unlike any previously documented in Sinaloa. The project, which ran from June 11 to July 11, 2025, received funding from the U.S. National Science Foundation and benefited from collaboration with the INAH Sinaloa Center and local residents.

Among the discoveries was a small crematorium, measuring 1.20 by 0.60 meters, with walls crafted from adobe and crushed shells. Inside, researchers found bone fragments, suggesting it was used for the cremation of infants. This points to a high infant mortality rate in pre-Hispanic times. Accompanying the remains were pieces of Aztatlán pottery, a ceramic type used between 600 and 1000 AD.

Just a week later, a larger crematorium, 2.50 by 1.40 meters, was uncovered. While it contained significant amounts of ash and charcoal, human bone remains were largely absent, indicating that ancient families likely removed most of the incinerated material.

"Just as they had spaces to process marine and river products, it's possible they also had this type of construction as a system for mortuary treatment," Vivero Miranda explained. "This could suggest social differentiation, at least in the funerary sphere."

While specific dating for these crematoria is still pending, archaeologists draw comparisons to smaller, individual crematoria found at the La Playa site in Sonora, dated between 200 and 400 AD. Similar contexts in Arizona, USA, date between 1100 and 1300 AD.

The team also uncovered an ossuary, or group burial, containing a cluster of long bones from at least four individuals. Two adult skulls with modified shapes were found atop the bones, with the remains of a teenager, estimated to be between 10 and 15 years old, beneath. This discovery echoes a similar burial reported by Gordon Ekholm in the late 1930s at Site 117 in Chorohui, belonging to the Huatabampo phase (650 to 1000 AD).

"We are obtaining novel information, data that had not been reported for Guasave, which helps us understand more about the ancient groups of this region," Vivero Miranda stated.

The archaeologist suggests that groups inhabiting the Sinaloa River's alluvial plain may have visited Macapule Island seasonally. Shell middens found there, up to 20 centimeters thick and containing burned bone fragments, suggest the transformation of the landscape. Vivero Miranda theorizes that these areas might have served as sites of worship for their ancestors, intentionally preserved against the elements for future visits.

The ongoing research continues to unlock the secrets of the Urvich fortress, offering invaluable insights into the pre-Hispanic past of the region.