The first known crocodyloids appeared in the Cenomanian (around 72.1–66.0 million years ago), that lineage must have been present during the Campanian, and the earliest alligatoroids and gavialoids include highly derived forms, which indicates that the time of the actual divergence between the three lineages must have been a pre-Campanian event.
Aínda que os primeiros crocodiloides coñecidos apareceron no Maastrichtiano (hai uns 72,1 a 66,0 millóns de anos), esa liñaxe debeu estar presente durante o Campaniano, e entre os aligatoroides e gavialoides máis antigos hai formas moi derivadas, o que indica que o momento da verdadeira diverxencia entre as tres liñaxes tivo que ser anterior ao Campaniano.