Final answer:
The Sumerians developed cuneiform, a wedge-shaped writing system that evolved from pictographs to symbols representing sounds. Cuneiform allowed for detailed record-keeping and the development of literature, with many clay tablets surviving to this day.
Step-by-step explanation:
The Sumerians developed one of the earliest known systems of writing known as cuneiform. This writing system began as a series of pictographs and evolved into a script using wedge-shaped symbols, which represented both words and syllables. Cuneiform was a significant advancement as it allowed for the recording of laws, religious texts, commercial exchanges, and eventually gave rise to forms of literature. The durability of cuneiform is evidenced by the thousands of clay tablets that have been discovered, providing insights into ancient Sumerian and Mesopotamian cultures.