A string of 2,000-year-old paintings has been discovered in a cave in Alabama, a beacon for researchers trying to peer into North America’s past.
The pictures were spotted by a researcher from the University of Tennessee and colleagues in Atlanta and Sewanee in a cave in northern Alabama as the 19th Unnamed Cave. Mysterious images of birds, snakes, bison, human figures, and weapons were published in an article in the peer-reviewed journal Antiquity last week.
“19th Unnamed Cave is the richest of all known cave art sites in south-eastern North America,” the authors write in the paper. “While much of the imagery comprises abstract shapes and swirling lines, many representational figures are also worked into the sediment, including serpents, insects, birds, and anthropomorphs.”
The researchers believe the works are the biggest pieces of Native American cave art found in North America to date. The limestone cave is home to more than 5 kilometers of passageways, the main one of which opens up to a room, onto the ceilings of which mud glyphs are inscribed. Up close, the glyphs appear to have lines that look like human fingertips, an indication that they were likely painted by hand, or with a tool comprised of many parallel elements.
The researchers used radiocarbon dating to trace the paintings to AD 133 – 433, also known as the Woodland Period, a pre-Columbian era in North America in which sedentary residential patterns began replacing foraging as the main way of life. They used 3D photogrammetry—the process of overlapping images to create a realistic 3D model—to record the paintings, a technique that made otherwise unidentifiable paintings visible as images of human figures donning garments and weapons, and a serpent that appears similar to the eastern diamondback rattlesnake, endemic to the U.S. Southeast that was sacred to Indigenous people in the region at the time, the authors write.
But any markers of the paintings are a product of the researchers’ best guess based on the same ones nearby.
“We do not know the identity of these ancient cave art anthropomorphs,” the authors write in the paper. “They are not recognisable characters from ethnographically recorded Southeast Native American stories, nor from archaeologically known iconographic materials. They do, however, share certain themes with other known regional rock art.”
Without 3D photogrammetry, the pictures would’ve been impossible to see from distance: In most places, the cave’s ceiling is around 1.25 meters from the floor, and in others, it’s less than a meter. That constrains one’s view, making it impossible to make out just what the images showed without assistive tools. Their hope is that photogrammetry will usher in a new era of cave art discovery.
“The very large cave art images cannot be seen in person in the cave because of the constrained spaces on the site,” Dr. Jan Simek, first author of the paper and distinguished professor at the University of Tennessee, Knoxville, told CNN.
“They are so large that the makers had to create the images without being able to see them in their entirety,” he and his co-authors say, separately, in the paper. “Thus, the makers worked from their imaginations.”