Possible Clues:

• Dig find
• Prehistoric remnant
• Archaeologist's find
• Ancient remains as of plant hardened into rock
• Ancient remains preserved in rock
• Relic of former life preserved in stone
• One petrified girl is so frantic to keep up
• Fuddy-duddy with a couple of sons, in marked contrast
• It's a dead loss if it's 16 down
• Petrified relic