It contains one species, Rastosuchus hammeri, found in the Permian Rio do Rasto Formation of Brazil.

[4][5] A partial description of a nearly complete skull now assigned to this taxon was presented by Barberena & Dias (1998),[6] and the phylogenetic position (as the "Serra do Cadeado short-snouted rhinesuchid") was assessed by Eltink et al.

The species name honors William R. Hammer, who is best known for his work on Gondwanan fossil tetrapods.

In addition to the holotype and previously described complete skull, additional material includes fragmentary lower jaws and one partial postcranial skeleton including the pectoral girdle, hindlimb, vertebrae, and ribs.

Below is the topology recovered by Eltink et al. (2016):[7] Dendrerpeton Eryops Trimerorhachis Konzhukovia Tryphosuchus Lapillopsis Peltobatrachus Lydekkerina Mastodonsaurus Benthosuchus Rhineceps Rhinesuchus Uranocentrodon Broomistega Australerpeton Rastosuchus (Serra do Cadeado short-snouted) Laccosaurus