American naturalist and cryptozoologist Ivan T. Sanderson (1911-1973) coined the term Out-Of-Place-Artifacts to describe various anomalous objects of historical, archeological, or paleontological interest which have been found throughout the Earth’s strata or in geological formations where they should not be located, according to conventional scientific theory.
Such discoveries challenge historical chronology by being “too advanced” for the level of civilization at the time, or show “human presence” well before man was thought to exist.
Perhaps the most famous example is the Antikythera mechanism, an ancient analog computer designed to predict astronomical positions and eclipses for calendrical and astrological purposes. Recovered in 1901 from a shipwreck off a Greek island, its clockwork-like appearance dates to 1,000 years before clocks were invented.