The Negro River, the major tributary that runs through the Brazilian Amazon, has reached historic lows, revealing millennia-old carvings previously hidden underwater.
The engravings deeply etched into the black rock along the riverbanks represent human faces, animals and other figures, and are thought to be 1000 to 2000 years old, archaeologists said.
“They allow us to understand the way of life of prehistoric populations,” Jaime de Santana Oliveira, an archaeologist with Brazil’s National Historic and Artistic Heritage Institute, said.
The scientists think other rocks at the site were used to sharpen arrows and stone tools.