crocodylomorphs

Crocodylomorphs are a clade of archosaurs that includes the living crocodilians and a diverse array of extinct relatives. They first appeared in the Late Permian and over hundreds of millions of years became one of the most enduring crocodyliform lineages. The group is defined as all crocodylomorphs closer to modern Crocodylia than to other archosaurs, and it includes notable subgroups such as Notosuchia, Neosuchia, and Thalattosuchia.

Notosuchians were often small to medium-sized and occupied terrestrial or semi-arid environments, while neosuchians include many aquatic and semi-aquatic forms and encompass the lineage leading to crown Crocodylia. Thalattosuchians adapted to marine life and are known from Jurassic and Cretaceous seas. Anatomically, crocodylomorphs show substantial diversity; many had elongated snouts in some lineages, while others possessed shorter, more robust skulls. They shared features such as osteoderms along the back and teeth suited to carnivory, with ecological roles ranging from small predators to large ambush predators.

Ecologically, crocodylomorphs occupied a broad range of niches through the Mesozoic, from freshwater to marine habitats, and their fossils have a global distribution. Following the end-Triassic extinction, neosuchians diversified and expanded into diverse aquatic and coastal habitats, with several lineages persisting into the Cretaceous and, in some cases, the Paleogene. Today, only Crocodylia survives, comprising alligators, caimans, crocodiles, and gharials. Crocodylomorphs remain an essential group for understanding the evolution of crocodilians and archosaurs.