Petroglyph

Petroglyphs, estimated to be 20,000 years old are classified as protected monuments and have been added to the tentative list of UNESCO's World Heritage Sites.

Around 7,000 to 9,000 years ago, following the introduction of a number of precursors of writing systems, the existence and creation of petroglyphs began to suffer and tail off, with different forms of art, such as pictographs and ideograms, taking their place.

[6] Later glyphs from the Nordic Bronze Age in Scandinavia seem to refer to some form of territorial boundary between tribes, in addition to holding possible religious meanings.

In 1853, George Tate presented a paper to the Berwick Naturalists' Club, at which a John Collingwood Bruce agreed that the carvings had "... a common origin, and indicate a symbolic meaning, representing some popular thought.

[8] Other theories suggest that petroglyphs were carved by spiritual leaders, such as shamans, in an altered state of consciousness,[9] perhaps induced by the use of natural hallucinogens.

Many of the geometric patterns (known as form constants) which recur in petroglyphs and cave paintings have been shown by David Lewis-Williams to be hardwired into the human brain.

[10] Though the San people's artworks are predominantly paintings, the beliefs behind them can perhaps be used as a basis for understanding other types of rock art, including petroglyphs.

To quote from the RARI website: Using knowledge of San beliefs, researchers have shown that the art played a fundamental part in the religious lives of its painters.

It is petroglyph depicting a stick figure with an oversized phallus and carved in Lapa do Santo, a cave in central-eastern Brazil and dates from 12,000 to 9,000 years ago.