antehistoric
/ænˈtɛhɪˌstrɪk/Definitions
1. adjective
relating to or coming before history, especially in a chronological sense.
“The discovery of the ancient city was considered antehistoric, as it predated written records.”
2. noun
a thing or event that occurs before history, especially in a chronological sense.
“The antehistoric period of human existence is a subject of ongoing research.”