May 20: edit
- 1902 - Oliver Bulman was born in London, England.
- 2002 - Stephen Jay Gould died of cancer in New York City, New York, USA at age 60.
2015 - Brandon R. Peecook and Christian A. Sidor reported the first non-avian dinosaur fossil discovered in the US state of Washington, a large theropod from the Campanian Cedar District Formation.
Lida Xing and others reinterpreted the Early Cretaceous small non-avian theropod ichnospecies Wupus agilis from China as the tracks of a heron-like bird.