These stone “cylinder seals ... around 3350 to 3000 B.C.E. These early writing systems featured symbols that were pressed or carved into wet clay. But where did those symbols come from?

This piece of clay contains some of the earliest writing in the world. It's called 'cuneiform,' which means wedge-shaped. This tablet is a record of the daily beer rations for workers. Beer here ...

The finds, which also include dozens of clay sealings, contain details of a metric system used to measure resources, as well ...

The Indus people wrote on soft clay using pointed sticks or by scratching marks onto stone and metal ... Image caption, These seals with writing on were found in the city of Mohenjo-Daro.