It contains only one species, the keeled vine snake (Proahaetulla antiqua), which is endemic to the Western Ghats of India.

[1] Proahaetulla is considered to be the sister taxon to the genus Ahaetulla, which it diverged from an estimated 26.57 million years ago, during the mid-Oligocene.

[1] Due to its age, Proahaetulla may be one of the oldest monotypic lineages of snakes to still persist in the Western Ghats.

Proahaetulla is also the first deeply divergent snake genus to be described from the Western Ghats in over a century; numerous Indian snake species have had new genera created to reclassify them from the genera they were originally classified in, but Proahaetulla is completely new, possibly having never been encountered by science prior to its description as a new genus and species.

[1] It is a diurnal and arboreal species found in the high elevation rainforests of the far south of the Western Ghats.