Wiktionary
a. Of or pertaining to a race that predates Adam; pre-human. n. A member of any race that predates Adam.
Wikipedia
The Pre-Adamite hypothesis or Preadamism is the belief that humans (or an intelligent but non human creature) existed before the biblical character Adam. This assumption is contrary to beliefs describing Adam as the first human, as stated in the Bible and the Qur'an. Preadamism is therefore distinct from the conventional Abrahamic belief that Adam was the first human. Advocates of this hypothesis are known as "pre-Adamites", as are the humans believed by them to have existed before Adam. Preadamism has a long history, probably having its origins in early pagan responses to Abrahamic claims regarding the origins of the human race.
Usage examples of "pre-adamite".
Detached broken fossils of pre-adamite whales, fragments of their bones and skeletons, have within thirty years past, at various intervals, been found at the base of the Alps, in Lombardy, in France, in England, in Scotland, and in the States of Louisiana, Mississippi, and Alabama.
Of all the pre-adamite whales yet exhumed, by far the largest is the Alabama one mentioned in the last chapter, and that was less than seventy feet in length in the skeleton.
And the Schenckius,--the folio filled with casus rariores, which had strayed in among the rubbish of the bookstall on the boulevard,--and the noble old Vesalius with its grand frontispiece not unworthy of Titian, and the fine old Ambroise Pare, long waited for even in Paris and long ago, and the colossal Spigelius with his eviscerated beauties, and Dutch Bidloo with its miracles of fine engraving and bad dissection, and Italian Mascagni, the despair of all would-be imitators, and pre-Adamite John de Ketam, and antediluvian Berengarius Carpensis,--but why multiply names, every one of which brings back the accession of a book which was an event almost like the birth of an infant?
In the conversation which followed it was explained that because, centuries before, a Queen of Khauran had cohabited with a pre-Adamite demon, every so often a witch would be born in the royal family.
Vathek is a tale of the grandson of the Caliph Haroun, who, tormented by that ambition for super-terrestrial power, pleasure and learning which animates the average Gothic villain or Byronic hero (essentially cognate types), is lured by an evil genius to seek the subterranean throne of the mighty and fabulous pre-Adamite sultans in the fiery halls of Eblis, the Mahometan Devil.