Related Clues:

• It's been extinct since the late 17th century
• Bygone bird
• Half-wit
• Long-gone bird
• Symbol of density
• Erstwhile bird
• Clumsy extinct bird
• Flightless bird of yore
• Stupid sort
• Bygone flightless bird
• Bird extinct since the late 17th century
• Extinct bird, or birdbrain
• Lightweight
• One who is not very bright
• Extinct, flightless bird