Prestosuchus

Prestosuchus (meaning "Prestes' crocodile") is an extinct genus of pseudosuchian in the group Loricata, from the Middle Triassic of Brazil. Prestosuchus is one of the largest and most extensively described early loricatans, known from many specimens including partial skeletons and enormous skulls. All undisputed Prestosuchus fossils are from the lower Santa Maria Formation (Dinodontosaurus assemblage zone) of Rio Grande do Sul, Brazil. The type species, Prestosuchus chiniquensis, was originally named by Friedrich von Huene in 1938, though its original fossils were rather fragmentary compared to later finds. There has been some debate over exactly how many species are contained within Prestosuchus. Some purported Prestosuchus species are at other times regarded as unrelated pseudosuchians, such as Procerosuchus, Schultzsuchus ("Prestosuchus loricatus"), and Stagonosuchus ("Prestosuchus nyassicus"). Alongside relatives such as Saurosuchus and Postosuchus, Prestosuchus has historically been referred to as a "rauisuchian", as well as the defining member of the family Prestosuchidae. The validity of both of these groups is questionable. "Rauisuchia" is now considered a paraphyletic group of large carnivorous pseudosuchians ancestral to crocodylomorphs. Prestosuchidae is polyphyletic in its widest form, though it may retain some utility in a narrower sense centered on Prestosuchus.