Mexican archaeologists found some 3,000 cave paintings, some almost 2,000 years old, in the central Mexican state of Guanajuato, the National Anthropology and History Institute, or INAH, said.
Sources at the institute told Efe that the discoveries were made between August and October 2011, but were not announced until specialists confirmed their antiquity and completed their analyses.
The relics came to light through the Rupestral Art Project of the Victoria River Basin - which includes semi-desert regions in the states of Queretaro and Guanajuato - developed by INAH experts and directed by archaeologist Carlos Viramontes.
INAH said in a communique Friday that the pictographs were found at 40 rock sites in an arid northeastern area of Guanajuato.
It added that the oldest images refer to rites of passage, healing, prayers for rain and mountain worship, and were created by ancient hunter-gatherer societies that occupied the area during the first centuries A.D.
These paintings, with yellow, red and black the predominating colors, generally represent human figures with headdresses, robes and shields, as well as some as yet unidentified instruments. Often in hunting and battle scenes they carry bows and arrows.
“A great diversity of animals is also to be seen, chiefly deer, canines, insects like centipedes and spiders, a great variety of birds, generally with their wings outspread, and radiating circles that probably represent the sun,” Viramontes said.
The expert said that the ancient hunter-gatherers who “created images on rockfaces were doing more than just leaving an imprint of their collective memory of historic, climatic and ritual occurrences - they painted the exposed fronts and sheltered backs of boulders as points of contact between the material and spiritual world.”
That has been determined thanks to the symbolism they used to reflect the primeval worship of stone and mountain as living beings, he said.
Also discovered in the area were religious images and inscriptions from the colonial era painted by Otomi Indian communities, along with others created by ranchers and clergy of the 19th and 20th centuries.
The discoveries are added to the more than 70 rock-art locations discovered in Guanajuato since the late 1980s.
Mexico has hundreds of cave-painting sites, with outstanding examples in the states of Baja California, Chihuahua, Yucatan, Oaxaca, Tlaxcala, Durango and Nuevo Leon, as well as in the Valley of Mexico.
The oldest rupestral art documented in Mexico up to now is in Baja California and dates back some 7,400 years.