Pedra de Fogo Formation

The Pedra de Fogo Formation is an Early Permian (Kungurian) geological formation of the Parnaíba Basin, northeastern Brazil. It has outcrops mainly on the states of Maranhão and Piauí, as well as some in Tocantins. It is thought to have been deposited in a continental and lacustrine environment, with occasional marine influences, on seasonal floodplains, channels and small ponds.

This formation has produced abundant remains of both animals and plants, the majority of which is represented by vertebrates, like temnospondyl amphibians such as Prionosuchus, captorhinid reptiles, and fishes like chondrichthians, actinopterygians and sarcopterygians. Petrified wood is also widely known from the formation, to the point of being one of its main diagnostic features. The northern portions of the formation provide taxa continental in origin, the middle portion a mixture between continental and marine taxa and the southern portion exhibits a predominance of marine taxa.