Early and Primaeval

Early adjective - At or near the beginning of a period of time or course of events or before the usual or expected time.

Primaeval and early are semantically related. In some cases you can use "Primaeval" instead an adjective "Early".

Primaeval adjective - Having existed from the beginning; in an earliest or original stage or state.

Early and primaeval are semantically related. You can use "Early" instead an adjective "Primaeval".