True Crocodilians: Eusuchia Clade and Its Diverse Lineages

Eusuchia (meaning "true crocodilians") is a clade of crocodylians that includes all living and extinct species of true crocodiles, gharials, and false gharials. The group is defined by the presence of a long, narrow snout and a distinctive dental pattern.

Eusuchia is thought to have originated in the Early Cretaceous period, around 145 million years ago, and has since diversified into several different lineages, including the living species of true crocodiles (Crocodilia) and the extinct groups such as the Gavialidae (gharials) and the false gharials (Tomistomenidae).

Eusuchia is a paraphyletic group, meaning that it does not include all descendants of a common ancestor. The group is sister to the clade Thalattosuchia, which includes the extinct marine crocodylians.