Archaeologists in Mexico have found 4,926 well-preserved cave paintings in the north-eastern region of Burgos - previously thought not to have been inhabited by ancient cultures. The images in red, yellow, black and white depict humans, animals and insects, as well as sky-scapes and abstract scenes, and were found at 11 different sites. The walls of one cave are covered with 1,550 scenes.
     The paintings suggest that at least three groups of hunter-gatherers lived in the San Carlos mountain range. Experts hope to chemically analyse their pigments to find out their approximate age.
     Gustavo Ramirez, an archaeologist from Mexico's National Institute of Anthropology and History, said: "We have not found any ancient objects linked to the context, and because the paintings are on ravine walls and in the rainy season the sediments are washed away, all we have is gravel."
     In one of the caves, the experts found depictions of the atlatl, a pre-Hispanic hunting weapon that had not yet been seen in other paintings in the state of Tamaulipas.
     Martha Garcia Sanchez, another archaeologist involved in the study, said that very little is known about the cultures who lived in Tamaulipas. "These groups escaped the Spanish rule for 200 years because they fled to the Sierra de San Carlos where they had water, plants and animals to feed themselves," she added.

Edited from BBC News (23 May 2013)