April 22: edit
- 1893 - Sam W. Heads was born in Northumberland, England.
- 1908 - Ivan Yefremov was born in Vyritsa, Saint Petersburg Governorate, Russian Empire.
- 1957 - Richard Swann Lull died.
- 1961 - Scott D. Sampson was born in Vancouver, British Columbia, Canada.
2015 - Evan Thomas Saitta found evidence for sexual dimorphism in Stegosaurus mjosi, with one sex having larger oval-shaped plates and the other having tall, narrow plates.
Lida Xing published a study of the fossil dinosaur footprints of the Tuchengzi Formation in China.