“Proterozoic, for one” crossword clue

Reveal the answer to see why it works and where this clue has appeared before.EON is the answer to the New York Times crossword clue “Proterozoic, for one”. It was last seen in the puzzle of August 6, 2025, where it runs at 39 Down and fills 3 squares. It crosses 3 other entries in that grid — those are listed below and are the quickest way to confirm the letters you already have.