Historical clue formulations

• They can stand on their own two feet — 2019-08-29
• Ostriches and kangaroos, e.g. — 2017-04-12
• Birds, e.g. — 2015-03-07
• Humans and ostriches — 2012-06-14
• Man and ape — 2008-11-09
• Man and others — 2008-03-01
• Humans, e.g. — 2005-07-24
• Ladies and gentlemen — 2001-11-25
• Humans, e.g. — 2000-03-20
• Humans, among others — 1999-07-15
• They stand on their own two feet — 1995-03-21