In 2016, a rancher living about 300 miles south of the Texas border was doing construction on his property. His goal was to level a cave, so he brought in some workers and a bulldozer to help with the project. Little did they know they were about to unearth an archaeological gold mine.

As they were plowing through Avendaños Cave, the workers started turning up some strange artifacts on the San Francisco de Borja property, located in the northern Mexican state of Chihuahua. The rancher halted construction, took a picture of the finds, and sent them to archaeologist Emiliano Gallaga, the director of the School of Anthropology North of Mexico at the National Institute of Anthropology and History.

"The first [thing] we noticed was the head of the macaw in perfect condition," Gallaga says.

After being lost to the world for thousands of years, a naturally mummified prehistoric macaw head had emerged. The vibrant green of its plumes is still bright, and its keratin beak is intact. The bird is a military macaw, a medium-sized macaw that is extant today. Now, two years since being found, the mummified macaw has been dated to be 800 years older than other specimens in the region, pointing to clues about trade and religion in Late Archaic society.

Found Feathers

Along with the bird head, the archaeologists found the skeleton of an infant human and the lower half of a man with his legs tied together. Also found was a sea of stone points, textiles, and other artifacts dating back thousands of years. (See photos of extraordinary mummies, including a crocodile and a pet gazelle.)

View Images The head of the mummified macaw is still covered in bright green feathers. Photograph by Emiliano Gallaga, EAHNM-INAH

To date, 670 macaw remains dated around 1,200 AD have been found in the Southwest U.S. and Northwest Mexico. But the Avendaños Cave macaw is the first in northern Mexico outside of the prehistoric archaeological site of Paquimé. What's more, the mummy is about 2,000 years old, making it the oldest known specimen to date. (Related: "Look Inside an Ancient Egyptian Bird Mummy")

"One of the reasons Gallaga's find is really, really exciting is because of the early date," says Abigail Holeman, a University of Virginia administrator who has written on the religious significance of macaws in Paquimé, Chihuahua. "It does speak to the antiquity of their ritual importance."

For the Birds

Thousands of years ago, scarlet and military macaws were not native to current-day Paquimé, although their ancient remains are found throughout the region today. Military macaws like the mummified green one at Avendaños Cave could have been found south of the site, but they still weren't local. (Related: "Mummy Birds Recovered From Egypt Factory")

"It's still 400 kilometers [250 miles] that someone has to take it and bring it to this site," Gallaga says. "Not everybody can afford to bring a macaw from far away."

Many archaeologists think the birds were exotic pets owned by high-ranking members of society, like elites, shamans, and traders, and that they had economic importance. Like corn and buffalo hides, macaws were likely sold to coastal traders in exchange for sea shells and fish. (Read about why birds matter and are worth protecting.)

With the finding that the mummy macaw is 2,000 years old, Gallaga says locals were using and trading these birds earlier than originally thought. Some interpretations also say macaws had religious significance and were seen as winged intermediaries between Earth and the divine. (Read: "5 Facts About the Surprisingly Wide World of Animal Mummies")

"Those two interpretations don't preclude each other. They're not mutually exclusive," Holeman says, meaning the birds could have had religious and economic significance. "It's the early date that is really going to have a huge impact."

Since the cave hasn't been excavated before, more needs to be done for the archaeologists to learn about society in the Late Archaic period, and the role of macaws in it.

"We don't have information about these early settlements in this area," Gallaga says. "The next step is just to continue doing research in the area."