Traditionally, crocodiles and alligators were considered more closely related and grouped together in the taxon Brevirostres, to the exclusion of the gharials.

This classification was based on morphological studies primarily focused on analyzing skeletal traits of living and extinct fossil species.

[7] However, recent molecular studies using DNA sequencing have rejected Brevirostres upon finding the crocodiles and gavialids to be more closely related than the alligators.

The false gharial and other tomistomines were traditionally classified within the superfamily Crocodyloidea as close relatives of crocodiles, based solely on morphological evidence.

The below cladogram shows the results of the latest study, and Gavialoidea's relationships within Crocodylia: extinct basal Alligatoroids† Caiman Melanosuchus Paleosuchus Alligator "Crocodylus" megarhinus† Crocodylus Mecistops Osteolaemus Kentisuchus† Maroccosuchus† Paratomistoma† Dollosuchoides† Tomistoma cairense† Gavialis Tomistoma However, other analyses by different authors have continued to resolve thoracosaurs as members of Gavialoidea.