Major subgroups

All crocodilians both extinct and extant, as well as their close relatives, fall into the Crocodylomorpha. The slatoposuchids and sphenosuchids were Late Triassic to Mid Jurassic terrestrial, long-legged forms. The remaining crodoilians adopted a more aquatic lifestyle, and had shorter limbs and adaptations for swimming. Many groups evolved in the Jurassic and Cretaceous, and there are only three living families. Extinct families are indicated with a dagger (†).