[5] During the Jurassic, crocodylomorphs morphologically diversified into numerous niches, with the subgroups Neosuchia (which includes modern crocodilians) and the extinct Thalattosuchia adapting to aquatic life, while some terrestrial groups adopted herbivorous and omnivorous lifestyles.

The oldest known crocodylomorph is Trialestes, known from the Late Triassic (Carnian-Norian) of Argentina, around 231–225 million years ago,[6] the last groups of "sphenosuchians" persisted until the end of the Jurassic.

[5] During the Jurassic, crocodylomorphs diversified, including the emergence of herbivorous and omnivorous forms,[7] as well as the aquatically adapted Neosuchia and Thalattosuchia, with Thalattosuchia and several groups of neosuchians becoming adapted to a marine lifestyle over the Jurassic and Cretaceous[8] During the Cretaceous, the Notosuchia were a diverse group across the Southern Hemisphere occupying many diverse ecologies.

Prehistoric crocodiles are represented by many taxa, but since few major groups of the ancient forms are distinguishable, a conclusion on how to define new order-level clades is not yet possible.

The basal crocodylomorph Saltoposuchidae was defined by Speikman, 2023 as the most inclusive clade containing Saltoposuchus connectens, but not Sphenosuchus acutus, Carnufex carolinensis, and Trialestes romeri.

The clade Solidocrania was established by Alexander A. Ruebenstahl and colleagues in 2022 to unite crocodyliforms with their closest "sphenosuchian" relatives who both share similarly reinforced skulls.

Trialestes Pseudohesperosuchus Litargosuchus Hesperosuchus Kayentasuchus Dromicosuchus Sphenosuchus Junggarsuchus Almadasuchus Macelognathus The Crocodylomorpha comprise a variety of forms, shapes, and sizes, which occupied a range of habitats.