Researchers used 3D scanning technology to reveal what they say is the largest collection of cave art drawings ever found in North America.
Among the glyphs discovered on the ceiling of a cave in Alabama is a serpent-shaped figure that measures about 11 feet, scientists reported in research published Wednesday in the peer-reviewed journal Antiquity.
The five examples of Native American cave art documented in the study were the largest found and estimated to be 1,000 to 1,800 years old, said co-author Jan Simek, an archaeologist and professor of anthropology at the University of Tennessee. But the process used to create a photorealistic, virtual 3D model of the cave actually revealed "thousands of additional glyphs and images," according to a story documenting the research in the Ancient Art Archive.
"It was surprising to see them, but it wasn't surprising they were there," Simek told USA TODAY.
That's because archaeologists have found many examples of open-air rock art created before Spanish explorers arrived in North America. But much of that has been found by archaeologists exploring burial sites.
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These new revelations come after Simek – a board member of the non-profit archive – and study co-author Alan Cressler first published findings in 1999 about the cave, identified as "19th Unnamed Cave" to protect its location from looters. After Cressler subsequently noticed some additional faint mud drawings in the cave's ceiling, they decided to explore further.
To accurately capture the ceiling's topography, the study's third co-author Stephen Alvarez, who is also a founder of the Ancient Art Archive, proposed the 3D mapping project. He spent several months taking more than 16,000 high-resolution photographs in the more than 5,000-square-foot chamber.
Those overlapping photographs were stitched together into a 3D model using photogrammetry, a software technology also used in making virtual maps and environments, and virtual objects for video games such as Call of Duty.
Alvarez also built a custom computer to handle the processing after one computer's motherboard melted while compiling the images.
Within the powerful 3D software, the scientists could shine virtual light on the ceiling's surface to reveal previously unseen drawings. Many etchings were faint or obscured as humidity and rain had worn them away, the scientists said.
The 3D model also provided a better vantage point for assessing the cave surface because "the tight physical confines of the cave" required you to crouch or be prone to view it in person, they said. As a result, you are often too close to the ceiling to discern images. "We can actually drop the floor away from the ceiling in the model," Simek told USA TODAY.
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The original cave artists made these life-sized and larger drawings "without being able to see them in their entirety," the researchers wrote in Antiquity. "Thus, the makers worked from their imaginations, rather than from an unimpeded visual perspective."
What were they actually drawing? Since caves were sacred places to Native Americans of the Southeast U.S. – and considered "pathways to the underworld," the researchers write – the stylized human forms, depicted below with rattlesnakes, may represent religious spirits.
"We would characterize them as human-like forms, but it’s hard to tell whether they are humans in elaborate regalia or perhaps supernatural characters," Simek said. "Meaning is difficult this far into the past."
Ancient art in caves was unanticipated by many archaeologists, he said. "We were excited to see these things emerge through the process of this analytical technique," Simek said.
🆕: Archaeologists have discovered the largest known Native American cave art images. The massive artwork, found in Alabama, is over 1,000-years-old and may represent spirits of the underworld.
🧵 An #AntiquityThread (paper: https://t.co/BEfElkIz92) 1/ pic.twitter.com/RirvhbJC3K
— 🅰ntiquity Journal (@AntiquityJ) May 4, 2022
The scientists have shown the findings to the Eastern Band of Cherokees' annual archaeology conference. "They were quite fascinated by what we were seeing," Simek said.
The Cherokee Nation, along with the Muscogee Creek Nation, the Chickasaw Nation, and the Choctaw Nation, are among the tribes whose descendants lived in the region at the time the drawings were made.
Photogrammetry has subsequently been used in several other caves in the Southeast. "What amazes me about using 3D modeling is that a story that was laid down a thousand plus years ago and has been invisible can now be seen in its entirety," Alvarez said.
"The artists who engraved the cave are speaking to us," he said. "We can use 3D modeling to listen."
Follow Mike Snider on Twitter: @mikesnider.
This article originally appeared on USA TODAY: Alabama cave's ancient drawings revealed by digital scan technology