Related Clues:

• Long-gone birds
• Boneheads
• Dim bulbs, so to speak
• Lamebrains
• Dim bulbs
• Putdown of those with whom one disagrees
• Gullible sorts
• Figures (out)
• Extinct flightless birds
• Not-too-bright ones
• No-brainers?
• Some extinct birds
• Tomfools
• Schmoes
• Erstwhile egg-layers