- 1846 - Oliver Perry Hay was born.
- 1956 - Helen F. James was born in Hot Springs, Arkansas, USA.
- 1977 - Roman Kozłowski died.
Phylogeny of Basal Iguanodonts (Dinosauria: Ornithischia): An Update
Andrew T. McDonald
published 22 May 2012
Limb-Bone Scaling Indicates Diverse Stance and Gait in Quadrupedal Ornithischian Dinosaurs
Susannah C. R. Maidment, Deborah H. Linton, Paul Upchurch, Paul M. Barrett
published 22 May 2012