[5] In 2021, Madzia et al. registered Brachylophosaurini in the PhyloCode and formally defined it as "The largest clade containing Brachylophosaurus canadensis but not Edmontosaurus regalis, Hadrosaurus foulkii, Kritosaurus navajovius and Saurolophus osborni".
[citation needed] In 1989, Michael Brett-Surman proposed the name Kritosaurini as a tribe of hadrosaurines that contained Aralosaurus, Brachylophosaurus, Hadrosaurus, and Kritosaurus (including Gryposaurus).
[7] It was not until 2014 that Albert Prieto-Márquez officially defined and diagnosed Kritosaurini as the most exclusive clade of hadrosaurids containing Kritosaurus navajovius, Gryposaurus notabilis, and Naashoibitosaurus ostromi.
[8] Madia et al. (2021) defined the term under PhyloCode as "the largest clade containing Kritosaurus navajovius but not Brachylophosaurus canadensis, Edmontosaurus regalis, Hadrosaurus foulkii, Saurolophus osborni.
[4] Alarcón-Muñoz et al. (2023) suggested that austrokritosaurs shared an ancestor with the North American kritosaurins in the Santonian, about 85 million years ago, before dispersing into South America.