Historical clue formulations

• Rock instrument? — 2026-07-04
• Implement for a Neanderthal — 2018-12-03
• Paleolith, e.g. — 2018-04-28
• Paleolith — 2017-10-15
• Eolith or neolith — 2012-02-03
• Paleolithic hammer or ax — 2006-09-25