1. From 345 million to 310 million years ago; increase of land areas; primitive ammonites; winged insects
   - Mississippian, Lower Carboniferous, Lower Carboniferous period

Type of: geological period, period

Part of: Carboniferous, Carboniferous period

• cleansing agent
• Cleanthes
• cleanup
• cleanup position
• cleanup spot
• clear
• clear and present danger
• clear away
• clear liquid diet
• clear off
• clear out
• clear sailing
• clear the air
• clear the decks
• clear the throat
• clear up
• clear-air turbulence
• clear-cut
• clear-eyed
• clear-headedness
• clear-sighted
• clear-thinking
• clearance
• clearance sale
• clearcole