oopart

noun1

1. •
   An object found in a very unusual or apparently impossible archaeological context (like the Coso sparkplug found in an allegedly 500,000-year-old geode) which would challenge conventional historiography and chronology if authentic.

   • "Out-Of-Place-Artifacts." These ooparts are artifacts or objects that archeologists have found in digging into ancient civilizations and that appear to be out-of-place […] — 1989