Avestan
…became extinct, its religious texts were transmitted orally, then collected and put into writing during the Sasanian period (c. 400 – c. 500 CE). The extant material falls into two groups: Old Avestan (c. 1500 – c. 900 BCE) and Younger Avestan (c. 900 – c. 400 BCE). The immediate ancestor of Old Avestan was the…