The fragmentary remains of this animal have been found in the Pedra de Fogo Formation in the Parnaíba Basin of Northeastern Brazil, in the states of Piauí and Maranhão, and it was described by L.I.

[4] Based on related species and comparisons with living gharials, the total body length of this specimen has been estimated to reach greater than 5.5 metres (18 ft) long.

A study on the closely related Archegosaurus shows that it had a heat balance, gas exchange, osmoregulation, and digestion process more similar to that of fish than modern aquatic amphibians; the same probably applied to Prionosuchus as well.

The archegosaurs were a group of temnospondyls that occupied the ecological niche of crocodiles and alligators during the Permian, and of which the European genus Archegosaurus is typical.

The group became extinct at the end of the Permian and the niche was subsequently filled by other, new temnospondyls, later joined by reptiles such as the phytosaurs in the Triassic period.