Fig. 1: Reduced time calibrated strict consensus tree of the maximum parsimony analysis showing the position of Deinosuchus spp., Leidyosuchus canadensis, and Diplocynodon spp. as stem-crocodylians.

Borealosuchus griffithi has two alternative positions, either as sister to Diplocynodon spp. or an early diverging placement within Borealosuchus spp. (Supplementary Data 1 “Walter et al_[TNT]”). Purple diamonds and silhouettes correspond to known occurrences of very large to giant (≥7 m) crocodyliforms. Each of the illustrated taxa is associated with high-productivity wetland or marine habitats (see Supplementary information Table S1 for a list of taxa and sources). Ages are in Ma.