Writing
The invention of the first writing systems is roughly contemporary with the beginning of the Bronze Age of the late 4th millennium BC. The Sumerian archaic cuneiform script and the Egyptian hieroglyphs are generally considered the earliest writing systems, both emerging out of their ancestral proto-literate symbol systems from 3400 to 3200 BC with earliest coherent texts from about 2600 BC. It is generally agreed that Sumerian writing was an independent invention; however, it is debated whether Egyptian writing was developed completely independently of Sumerian, or was a case of cultural diffusion.
Proto-writing
In 2003, tortoise shells were found in 24 Neolithic graves excavated at Jiahu, Henan province, northern China, with radiocarbon dates from the 7th millennium BCE. According to some archaeologists, the symbols carved on the shells had similarities to the late 2nd millennium BCE oracle bone script. Others have dismissed this claim as insufficiently substantiated, claiming that simple geometric designs such as those found on the Jiahu shells cannot be linked to early writing.