The Shigir Idol – now dated as 11,600 years old – depicts eight “demon” faces.
The indecipherable code has been cracked after the idol – originally more than 17ft high – was subject to the latest scientific techniques.
The idol is three times as old as the Egyptian pyramids and was sculpted with jaw of a beaver, its teeth intact.
Scientists found it stood not in the ground but probably leaning against a rock outcrop for perhaps 20 years before toppling into an ancient and long-gone paleo-lake to be preserved for posterity.
Found in the Ural Mountains by tsarist gold prospectors in the 19th century, it was encased in peat for thousands of years and, despite being made of larch, is seen as one of the world’s oldest known examples of monumental art.
A haunting O-shaped mouth plus its mysterious zigzag etched lines and symbols show that Mesolithic had a “rather complicated world view” along with unexpectedly advanced artistic skills, scientists said.
The code is likely to refer to spirits, academics claim.
“The word ‘demon’, for example, has a very wide range of meanings even in English – from devil to good genius,” said Dr Zhilin, leading researcher at the Age Archeology Department.
“In fact, given that we do not know the context 11,500 years ago, we cannot say exactly what the (markings on the idol) depicted.
“Yet apparently these were some kind of spirits.
“Not deities, because we think that deities appeared later.”
He said: “We must not underestimate the people who created the idol.
“They had all the necessary tools and skills – and they had a rather complicated world view.
“All the world was inhabited with different spirits.
“And not only the animals and the trees but even the stones were animated.
“We think it was something close to animism.
“I see in these images unity and diversity of the world around.
“And it was definitely not divided just into kind and evil spirits.”
The idol is on display at the Sverdlovsk Regional History Museum in Yekaterinburg.