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.
History of study Munich specimens The holotype of Prestosuchus chiniquensis was discovered by Wilhelm Rau alongside the holotype of Rauisuchus tiradentes. Both were found in 1928 or 1929 within the Santa Maria Formation at Paleontological Site Chiniquá, near the city of São Pedro do Sul in Rio Grande do Sul, Brazil. The fossils were shipped back to Germany for study by the German paleontologist Friedrich von Huene. Von Huene named the genus Prestosuchus in 1938 in honor of Brazilian paleontologist Vicentino Prestes de Almeida.von Huene, F. (1938). Die fossilen Reptilien des südamerikanischen Gondwanalandes. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, 1938:142-151. The Chiniquá site is now part of the geopark of Paleorrota.
Von Huene (1938) recognized two specimens of Prestosuchus chiniquensis from the Chiniquá area. One specimen was a partial skeleton including a jaw and snout fragments, and its bones were labelled SNSB-BSPG AS XXV 1-3, 5-11, 28-41, and 49. In 1972, this specimen was designated as the lectotype of Prestosuchus chiniquensis. The other specimen, SNSB-BSPG AS XXV 7, consists of the upper part of the hip and sacrum. It was designated as the paralectotype of the species.
The lectotype and paralectotype are stored at the Bavarian State Collection for Palaeontology and Geology (Bayerische Staatsammlung für Paläontologie und Geologie, BSPG) institute of the Bavarian Natural History Collections (Staatliche Naturwissenschaftliche Sammlungen Bayerns, or SNSB) in Munich, Germany. Both have been redescribed by Desojo et al. (2020).
Huene named several more Prestosuchus-like reptiles shortly afterwards, although he did not consider them to be the same species as Prestosuchus chiniquensis. One specimen, with its fossils labelled as SNSB-BSPG AS XXV 131-139, received its own genus and species: Procerosuchus celer. Another specimen, with its fossils labelled SNSB-BSPG AS XXV 13–24, 26–27, and 44–48, was designated as a second species of Prestosuchus, Prestosuchus loricatus.
Some authors have considered Procerosuchus celer or Prestosuchus loricatus to be junior synonyms of Prestosuchus chiniquensis. Others have gone as far as to consider not only Procerosuchus celer a separate genus, but also "Prestosuchus" loricatus. Desojo & Rauhut (2024) established the new genus Schultzsuchus for "Prestosuchus" loricatus, as their analyses disputed a close relationship to Prestosuchus chiniquensis.
Porto Alegre specimens
Four Prestosuchus specimens are stored at the Universidade Federal do Rio Grande do Sul (UFRGS) in Porto Alegre. The first to be described was UFRGS-PV-0156-T, a massive and well-preserved skull discovered along with most of a vertebral column at the Pascual Sanga outcrop in Candelária. It was originally described by Barberena (1978) and has experienced much discussion as to its relations to the original Munich specimens. A more complete partial skeleton from Vale Verde, UFRGS-PV-0152-T, was studied by Nesbitt (2011) along with the Munich lectotype and UFRGS-PV-0156-T. It is anatomically similar to the latter specimen.
The most complete UFRGS specimen is UFRGS-PV-0629-T, a partial skeleton from Dona Francisca which was originally described in a thesis by Mastrantonio (2010). This specimen has been the subject of braincase (2013), skull (2019), and postcranial (2024) descriptions, as well as hip muscle reconstructions. The least complete UFRGS specimen is UFRGS-PV-0473-T, an isolated braincase which may be from the "Posto de Gasolina" outcrop in Dona Francisca.
Porto Alegre has one additional Prestosuchus specimen unaffiliated with the UFRGS: MCP-146, a portion of the hip area stored at the Museu de Ciências e Tecnologia of Pontífícia Universidade do Rio Grande do Sul.
Other specimens
Various other museums have their own Prestosuchus specimens. One of the most spectacular specimens, ULBRA-PVT-281, consists of a very large and complete skull and partial skeleton discovered at "Posto de Gasolina" and now stored at the Universidade Luterana do Brasil (ULBRA) in Canoas. This specimen was discovered in 2010 and was fully described by Roberto-Da-Silva et al. (2018/2019)
The Museu Paleontológico e Arqueológico Walter Ilha in São Pedro do Sul has a selection of Prestosuchus fossils collectively termed CPEZ-239b. CPEZ-239b corresponds to at least two juvenile individuals found at the Baum (Tree) Sanga outcrop, which were described by Lacerda et al. (2016).
The only Prestosuchus fossil stored outside of Brazil or Germany is MCZ 4167, an obscure and fragmentary specimen found at "Posto de Gasolina" and held at Harvard's Museum of Comparative Zoology in Cambridge, Massachusetts.
Taxonomic controversies
Prestosuchus has been the subject of constant dialogue over the taxonomy of its fossils. Many names have been proposed for the various fossils referred to Prestosuchus and its one or more constituent species. Some of these names are informal proposals rejected by the academic community, while others have been formally published in peer-reviewed studies.
A brief abstract by Kischlat & Barberena (1999) claimed that several Prestosuchus specimens, including the paralectotype of P. chiniquensis and the giant "Porto Alegre specimen" (i.e. UFRGS-PV-0156-T), actually deserve a new genus and species.Kischlat & Barberena (1999) Kischlat E-E, Barberena MC. Prestosuchus chiniquensis (Crurotarsi, Archosauria) does not need a neotype! Paleontologia em Destaque. 1999;14:53. Kischlat (2000) later used the name "Karamuru vorax" in reference to these fossils, citing the 1999 abstract as the name's origin. This is despite the fact that his 2000 study is the first explicit use of the name in any publication. In a section heading within the same 2000 study, Kischlat referred to "Prestosuchus" loricatus as "Abaporu" loricatus.Kischlat (2000) Kischlat E-E. Tecodôncios: a Aurora dos Arcossáurios no Triássico. In: Holz M, De Ros LF, editors. Paleontologia do Rio Grande do Sul. Porto Alegre: Editora da UFRGS; 2000. pp. 246–272. At no point does Kischlat assign type material to these proposed names.
These informal treatments do not pass ICZN standards for new scientific names, so "Karamuru vorax" and "Abaporu" are considered invalid nomina nuda by the wider community.Langer, Max C.; Ribeiro, Ana M.; Schultz, Cesar L.; Ferigolo, Jorge (2007). "The continental tetrapod-bearing Triassic of south Brazil". In Lucas, S.G.; Spielmann J.A. (eds.). The Global Triassic (PDF). New Mexico Museum of Natural History and Science Bulletin, 41. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 201–218. Archived from the original (pdf) on 2011-07-06. Later, Kischlat (2023) proposed that Prestosuchus chiniquensis should receive a new genus name, Huenesuchus. Although Kischlat admitted that Prestosuchus is a valid name, he preferred to replace that name under the argument that a single type species was not explicitly established by von Huene along ICZN guidelines. Other paleontologists immediately disagreed with Kischlat's arguments in informal contexts.
Publications relevant to Prestosuchus, starting with Kuhn (1961), have consistently treated P. chiniquensis as a valid type species. McDavid (2025) formally discussed the issue, citing Prestosuchus as the proper generic name since it had been diagnosed by Oskar Kuhn in 1961. Another publication, by Pêgas, Bandeira & Silva (2025), noted that Kuhn (1961) provided references to purported descriptions of the genus in Huene (1942) and Hoffstetter (1955). Pêgas and colleagues argued that these works (and, as a consequence, Kuhn's publication as well) lack any sort of statement of "characters that are purported to differentiate the taxon" that would fulfill the criteria from the Article 13.1. of ICZN. Instead, the authors pointed to Krebs (1976) as the publication fulfilling the criteria of the Code and making the name Prestosuchus nomenclaturally available. In any case, multiple research teams dispute Kischlat's attempts to establish alternative names for fossils typically referred to Prestosuchus.
A 2008 abstract by Desojo & Rauhut argued that Procerosuchus celer was a junior synonym of Prestosuchus chiniquensis. Later studies, many of which include the same authors, disagree with this preliminary finding. Desojo et al. (2020) indicated that "Prestosuchus" loricatus deserved its own genus, and that a new name was forthcoming. Desojo & Rauhut (2024) redescribed the remains of "Prestosuchus" loricatus and determined that it was a valid species of poposauroid, not closely related to Prestosuchus chiniquensis. In accordance with this finding, they placed "Prestosuchus" loricatus into a new genus, Schultzsuchus, named after Cesar Schultz.Stagonosuchus nyassicus is a possible loricatan known from two specimens discovered in the Manda Beds of Tanzania. It was originally named and described by von Huene (1938/1939), though it remained obscure for decades. Desojo et al. (2020) argued that it should be lumped into Prestosuchus as a second valid species, Prestosuchus nyassicus. However, a study from the same year did not recover the two species as sister taxa. A phylogenetic analysis by Smith et al. (2024) recovered Stagonosuchus outside Loricata and suggested that it could be included within Poposauroidea instead.
Description Like its relatives, Prestosuchus had a deep skull and serrated teeth. While it resembled a dinosaur in having a large body and upright posture, it was actually a pseudosuchian, meaning that it was an archosaur more closely related to modern crocodilians than to dinosaurs. Prestosuchus lived during the Middle Triassic in what is now Brazil. Initially it was estimated to be around 5 meters (17 feet) but a specimen discovered in 2010 suggest that Prestosuchus reached lengths of nearly 7 meters (23 feet) making it one of the largest Triassic pseudosuchians alongside Saurosuchus and Fasolasuchus. Prestosuchus probably walked on four legs like crocodilians, but unlike crocodilians, it had an upright semi-erect stance with limb bones placed below the hips.
Skull