Related Clues:

• An earlier one may be recalled
• Paleozoic, for one
• Historical stage
• Ruth's was 2.28
• Unique stretch in time
• Paleozoic, for example
• --- of Good Feelings
• Most important
• Several periods
• Period piece?
• Important historic period
• Geological time period
• Granny Smith throwaway
• Important time span
• Nucleus