Historical clue formulations

• It may be petrified — 2026-08-16
• Badlands discovery, maybe — 2025-07-17
• What's left of a dinosaur — 2020-03-10
• Bone to pick? — 2015-12-10
• Old fogy — 2015-02-01
• Old fogy — 2010-05-23
• Has-been — 2007-06-17
• Dinosaur remnant — 2005-05-16
• Old-fashioned one — 2003-09-28
• Thing of the past — 1999-08-27