From the National Geographic, “Oldest Buddhist Shrine Uncovered In Nepal May Push Back the Buddha’s Birth Date“:
Digging beneath a central shrine, the researchers uncovered postholes pointing to a wooden railing surrounding a tree shrine and dating to around 550 B.C., says Coningham. They also found an older brick structure.
The center of the shrine was unroofed, the team found, and contained mineralized tree roots, surrounded by clay floors worn smooth by visitors. It was likely an ancient bodhigara, or tree shrine.
The tree roots appear to have been fertilized, and although bodhigara are found in older Indian traditions, the shrine lacked the signs of sacrifices or offerings found at such sites.
“It was very clean, in fact, which points to the Buddhist tradition of nonviolence and nonofferings,” says Coningham.
Julia Shaw, a lecturer in South Asian archaeology at University College London, called the claims for a wooden railing surrounding a possible tree shrine convincing but speculative.
She was cautious about the oldest Buddhist shrine claim.
“The worship of trees, often at simple altars, was a ubiquitous feature of ancient Indian religions, and given the degree of overlap between Buddhist ritual and pre-existing traditions, it is also possible that what is being described represents an older tree shrine quite disconnected from the worship of the historical Buddha,” Shaw says.
“Still, it does indeed present some new insights into the archaeology of Indian ritual in general,” she adds.