Via MSNBC:

In the mountains of northeastern Mexico, archaeologists have
unearthed thousands of ancient paintings on the walls of caves and
ravines from a time before Spanish rule.

The rock art
offers rare evidence from native cultures living in the area around the
Sierra de San Carlos, a mountain range in Mexico’s state of
Tamaulipas, researchers say.

Almost 5,000 of these paintings were
found across 11 different sites in the region, the researchers said.
Created with red, yellow, black and white pigments, the images show
animals from deer to lizards to centipedes, as well as people.
Depictions of tents, hunting, fishing and possibly astronomical charts also offer a glimpse into the life of this mysterious culture….