This mask could be a very important artifact. Although it looks like a decidedly creepy prop from a horror film, this archaeological find is challenging what we thought we knew about the development of technology in pre-Columbian America.

Anthropologists from the University of Buenos Aires reveal the story of this relic in a new study published in the journal Antiquity. The mask, they explain, was found poking out the earth near the small village of La Quebrada in Catamarca Province of northern Argentina after the summer rainy season in 2005. The 18 by 15 centimeter (7 by 5.9 inch) rectangular mask features some unrefined anthropomorphic traits – a pair of eye holes, a nose hole, and a basic mouth hole – indicating it was consciously designed to look like a human.

Local residents alerted archaeologists, who quickly discovered it was buried alongside several bones belong to at least 14 people, including men, women, and children. A handful of the bones were stained with the characteristic green color of copper carbonate from the mask. This suggests the mask had some kind of funerary ritual purpose and was used to represent an ancestor.

"The Ancestor cult is a very ancient and widespread cosmology in the Andean region, with of course, local and historical variants," study author Leticia Inés Cortés told IFLScience. "There is also a number of evidence that shows that, at that time, mobile groups used to transport the bodies of their dead or parts of these bodies from place to place along with them." 

"In that sense, I argued that the mask – a recognizable “subject” within the undifferentiated bodies - acts as the synthesis of that community of men and women, children and adults," she added. "In other words, the humanity of the mask constitutes a metaphor of the community buried there, the ancestors."

The study notes the human remains date back to around 3,000 years ago. Since the mask was placed alongside the bodies around the time of the burial, it means the mask is the “oldest intentionally shaped copper object discovered in the Andes.”

Researchers analyzed the chemical composition of the mask to discover that the copper was sourced from ores also found in Catamarca Province, around 70 kilometers (44 miles) away. Archaeologists have previously discovered gold sheets shaped as beads from the northern Titicaca area of Peru made approximately 3,733 years ago. There are also reports of copper flecks that date from around 3,000 years in Mina Perdida, Peru. However, this still remains the first crafted piece of copper discovered in the Andes. 

The research was funded by Agencia Nacional de Promoción Científica y Tecnológica, Consejo Nacional de Investigaciones Científicas y Técnicas, and the Universidad Nacional de La Plata, Argentina.