Ancient artists who painted caves in the Basque region between 16,000 and 14,000 years ago followed a clear visual plan, according to a new study. The research found the paintings were arranged using shared rules instead of being placed at random, pointing to a graphic system with an ordered structure.
The study, published in the Journal of Archaeological Method and Theory, was led by Iñaki Intxaurbe, a researcher at the EHU-University of the Basque Country. He examined more than 500 painted figures from nine decorated caves in the Basque Country using network analysis and statistical tools to study how animals appeared together, where they were placed on cave panels, and which direction they faced.
The results showed a repeated pattern across the caves. Bison, horses, and ibex, or wild goats, formed the center of many compositions. Other animals appeared around them in supporting roles. Bison often held the most central place within the networks, although horses and ibex also formed part of a stable group that shaped the overall layout.
Animal direction followed clear rules as well. Horses usually faced right, while bison and most other animals faced left. A small number of figures broke this pattern, though those cases were rare. The same arrangement appeared across different caves, suggesting shared artistic rules instead of random choices.
The research focused on Magdalenian cave art from the Bay of Biscay region, an area linking the Iberian Peninsula with the rest of western Europe. Instead of asking what each image meant, the team studied how the figures were arranged. They treated the paintings as a visual system with its own internal order.
Several types of analysis reached the same result. Researchers built networks based on animals appearing together on the same panels. They also used filtered networks, minimum spanning trees, and other statistical methods. Each approach pointed to the same pattern, giving strong support for an organized graphic system.
The findings support an idea first suggested many years ago. Archaeologists had noticed that many cave animals faced left and believed the placement followed shared rules. One older idea argued artists painted left-facing animals because most were right-handed. This study does not support that view. Horses are among the most common figures, yet they usually face right.
The research does not try to explain what the paintings meant. Instead, the author argues the artwork followed a shared graphic code whose meaning has been lost over time. The caves chosen for painting also appear to have held special importance because only certain caves contain this type of art.
The researcher made both the database and the analytical methods freely available. Other researchers now have a way to compare cave art from France, the Iberian Peninsula, and other regions using the same approach. The method also suits the study of ancient writing systems, old inscriptions, and historical scripts by examining how symbols appear together and follow repeated patterns.
The meaning behind these Ice Age paintings still escapes us. Their structure does not. This study shows the artists worked within a shared visual system that shaped how animals appeared on cave walls thousands of years ago.