A stone idol of Jainism founder Mahaveer, dating back to the 8th century AD, was excavated from the bank of the Amaravathi River at Swaminathapuram village near the temple town on Tuesday.
A team comprising archaeologist P. Narayanamurthy, Deputy Superintending Archaeologist Murtheswari and historian Raja conducted the dating of the idol.
The five-foot-tall and four-foot-wide idol has been carved out in white granite stone. Mahaveer, with a halo around his head, is seen in a reclining posture. Two cobras are carved on either side of the figure.
An umbrella appears over the head.
The face of the idol is slightly damaged. However, the umbrella and arch behind him are intact, they said.
The excavation site is said to straddle the Pandia and Kongu kingdoms.
The idol confirms that Jainism flourished in these regions during the period.