Preceding the advent of modern humanity, Homo sapiens(adjective)
One of the human-like creatures prior to Homo sapiens.(noun)
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Use "prehuman" in a sentence
"The Dancer is a "clever little prehuman statue," she learns, which was discovered on an uninhabited planet by the hapless crew of a space freighter and has been wreaking havoc ever since."
"Magisterial in its learning and admirably immodest in its ambition, the book traces the history of political organization and principle from "prehuman times" up to the period of the French Revolution."
"The new finds all belong to a prehuman species of that time called Australopithecus sediba , discovered in 2008."