Related Clues:

• Important time span
• R-V inhabitants?
• See 25-Down
• Archeozoic, e.g.
• Depression, for one
• 1970's-80's cause, for short
• Gay 90's, e.g.
• History text topic
• It may have periods
• Feminist pitcher's concern?
• Actor/comic Gilliam
• Geological time
• Geologist's time division
• Oft-nicknamed period
• Geological period