Historical clue formulations

• Diving bird — 2018-11-13
• Helldiver, e.g. — 2016-08-27
• Duck lookalike — 2016-07-08
• Diving bird — 2014-03-22
• Loonlike bird — 2010-07-20
• Relative of a loon — 2007-08-11
• Loonlike bird — 2005-08-21
• Cousin of a loon — 2000-12-06
• Loon's cousin — 2000-11-05
• Diving bird — 1998-01-04
• Diving bird — 1997-10-26
• Cousin of a loon — 1997-10-05
• Diving bird — 1997-09-08
• Helldiver — 1996-10-19
• Cousin of the loon — 1996-08-31
• Diving bird — 1996-05-28
• Diving bird — 1996-01-23
• Diving bird — 1995-12-17
• Pied-billed bird — 1994-04-10