Historical clue formulations

• Mastodon features — 2024-04-17
• Mastodons' defenses — 2023-12-17
• Walrus weapons — 2022-02-02
• Protrusions near a trunk, maybe — 2021-02-19
• Pair of elephants? — 2015-01-16
• Mastodon features — 2013-11-03
• Walrus features — 2006-12-04
• Mammoth things — 2003-05-25
• Wild boar features — 1998-12-31