Related Clues:

• Untold centuries
• Significant time period
• Longest time span, geologically
• Prohibition, e.g.
• Coldwell Banker competitor
• Silent ___ (time before the talkies)
• An earlier one may be recalled
• Many moons
• Paleozoic, for one
• Geological time division
• Historical stage
• Ruth's was 2.28
• Unique stretch in time
• Paleozoic, for example
• --- of Good Feelings