What are the oldest known writing systems in human history?

The oldest known writing systems emerged around 3200–3000 BCE. Sumerian cuneiform, developed in ancient Mesopotamia (modern Iraq), is generally considered the earliest, beginning as pictographic symbols used for record-keeping and evolving into wedge-shaped marks pressed into clay tablets. Egyptian hieroglyphics appeared at roughly the same time, around 3200 BCE, and may have developed independently or with some Mesopotamian influence. The Proto-Elamite script from ancient Iran also appeared around this period, though it remains largely undeciphered. The Indus Valley script, used in the civilization centered in modern Pakistan and northwest India, dates to around 2600 BCE but has not been deciphered. Chinese writing appears later, around 1200 BCE, in the form of oracle bone inscriptions.