Historical clue formulations

• One standing on one's own two feet? — 2023-03-11
• Ostrich or kangaroo — 2021-11-07
• Human, ape or kangaroo — 2021-01-21
• Upstanding one? — 2014-07-04
• Two-legged creature — 2013-08-26
• Bird or human — 2012-08-01
• Human or kangaroo — 2012-01-17
• Any member of the genus Homo — 2010-09-28
• The Abominable Snowman, for one — 2010-09-04
• One on two feet — 2008-03-30
• Two-legged — 1995-01-02