FARMER ACCIDENTALLY DIGS UP AN ANCIENT ARTIFACT WITH A HISTORY THAT LEAVES ARCHEOLOGISTS BAFFLED

The farmer was aware that as soon as the sun would be setting, it will become difficult for him to plow afterward as the weather would turn a bit chilly. The moment he was trying to plow a patch he thought he heard a noise. For once he thought he had mistaken but his doubt materialized as soon as he came back on the same spot while plowing. What was the object that had created the hurdle or was he really mistaken?