A chain of monumental rock art sites dominated by gigantic snake images along the Orinoco River in South America could be prehistoric territorial markers, according to new research. Their sheer size and prominence in the landscape make the engravings, which were hewn along the Middle and Upper sections of the river rapids, outliers in the rock art of the period and area. Though shallowly carved into the rock – less than a centimeter deep – they remain visible at great distances even after at least 2,000 years (though their age is unclear), write Philip Riris of Bournemouth University, José Ramón Oliver of University College London and Natalia Lozada Mendieta of Universidad de Los Andes, Bogotá in a paper in the academic journal Antiquity .
The engravings' age is unknown but the team estimates they date back at least two millennia. The range of motifs is varied and includes humans, geometric forms, venomous arthropods – but predominant among the animals are serpents. Giant snakes, larger than any known today.
Not all the monumental rock art sites along the Middle and Upper Orinoco, which flows through modern-day Colombia and Venezuela, feature gigantic snakes. But most do, the authors say based on examination of the literature and the discovery of previously unknown sites. The longest of the snake images zigzags more than 40 meters (131 feet), which the team says may make its panel the largest single rock engraving in the world.
While northern South America feature.