Photograph of an Olmec stone roller stamp and a drawing of its rolled-out seal

Artifact date c. 650 B.C.E.; found at San Andres, Tabasco, Mexico

In 2002 anthropologist Mary Pohl (1942–) and a group of fellow archaeologists (scientists who dig up and examine artifacts, remains, and monuments of past human life) were working in San Andres, a site near the ancient Olmec city of La Venta in the western part of the Mexican state of Tabasco. They found a ceramic cylinder (tube-shaped object) with raised, carved symbols on it. Nearby they found small fragments of flattened jade inscribed with similar symbols. The ceramic cylinder is believed to have been a roller stamp or seal. When it was rolled in ink or dyes, it could be used to print the symbols from its raised carvings onto cloth, or even human skin as a kind of body decoration. Scientific testing indicated that the cylinder and other artifacts found...