Gavialis likely first appeared in the Indian Subcontinent in the Pliocene and dispersed into the Malay Archipelago through a path called the Siva–Malayan route in the Quaternary.

Remains attributed to Gavialis have also been found on Sulawesi and Woodlark Island east of the Wallace Line, suggesting a prehistoric lineage of Gavialis was able to traverse marine environments and reach places possibly as far as western Oceania.

[3] The genus Gavialis was reevaluated in 2018 based on specimens in the Natural History Museum, London that were collected in the Sivalik Hills.

Rhamphosuchus is proposed to include G. leptodus, G. pachyrhynchus, G. curvirostris and G. breviceps.

[4] The below cladogram of the major extant crocodile groups is based on the latest molecular studies, and shows the gharial's close relationship to the false gharial, and how the gavialids and crocodiles are more closely related than the alligatoroids:[5][6][7][8][9] Caiman Melanosuchus Paleosuchus Alligator Crocodylus Mecistops Osteolaemus Gavialis Tomistoma Here is a more detailed cladogram that shows Gavialis's proposed placement within Gavialidae, including extinct members:[8] Gavialis gangeticus Gharial Gavialis bengawanicus† Gavialis browni† Gryposuchus colombianus† Ikanogavialis† Gryposuchus pachakamue† Piscogavialis† Harpacochampsa† Toyotamaphimeia† Penghusuchus† Gavialosuchus† Tomistoma lusitanicum† Tomistoma schlegelii False gharial