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15-514: Gualosuchus is an extinct genus of proterochampsian archosauriform from the Middle Triassic Chañares Formation of Argentina . The type and only species is Gualosuchus reigi , named by paleontologist Alfred Romer in 1971. Its skull length is 40 cm long making it quite a large proterochampsids. Gualosuchus also said to have a more robust humerus and tibia compared to other proterochampsids. This article about

30-920: A Triassic reptile is a stub . You can help Misplaced Pages by expanding it . Proterochampsia Proterochampsia is a clade of early archosauriform reptiles from the Triassic period. It includes the Proterochampsidae (e.g. Proterochampsa , Chanaresuchus and Tropidosuchus ) and probably also the Doswelliidae . Nesbitt (2011) defines Proterochampsia as a stem-based taxon that includes Proterochampsa barrionuevoi and all forms more closely related to it than Euparkeria capensis , Erythrosuchus africanus , Passer domesticus (the House Sparrow), or Crocodylus niloticus (the Nile crocodile). Therefore,

45-403: A clade formed by Proterochampsidae and Doswelliidae , defined Proterochampsia by up-facing nostrils, maxilla -to- prefrontal contact, the tooth bearing part of the upper jaw being curved downwards, neck and front back vertebrae lacking a postzygodiapophyseal lamina, tibia with straight cnemial crest, fifth metatarsal that is not hook-shaped in its inner end, well developed foot phalanges on

60-1233: A highly diverse Proterochampsia, which includes a deep split between doswelliids, including forms with aquatic adaptations, and proterochampsids. Proterochampsia was found to be the sister taxon of Archosauria , whose living representatives consist of birds and crocodilians . Multiple updated versions of the analysis performed by Ezcurra have been published, including the analysis of Paes-Neto and colleagues in their 2023 description of two new genera of proterochampsids, Kuruxuchampsa and Pinheirochampsa . Proterosuchidae Sarmatosuchus Cuyosuchus Erythrosuchidae Asperoris Dorosuchus Euparkeria Halazhaisuchus Avemetatarsalia Pseudosuchia Litorosuchus Vancleavea Polymorphodon Jaxtasuchus Doswellia Rugarhynchos ?  Stenoscelida Sphodrosaurus Proterochampsa barrionuevoi Proterochampsa nodosa ?  Stenoscelida Cerritosaurus ?  Stenoscelida Tropidosuchus MCP-4195-V ?  Stenoscelida Gualosuchus Pseudochampsa Chanaresuchus Kuruxuchampsa Pinheirochampsa Rhadinosuchus Synapomorphies Examples of apomorphy are

75-477: A synapomorphy is the marker for the most recent common ancestor of the monophyletic group consisting of a set of taxa in a cladogram. What counts as a synapomorphy for one clade may well be a primitive character or plesiomorphy at a less inclusive or nested clade. For example, the presence of mammary glands is a synapomorphy for mammals in relation to tetrapods but is a symplesiomorphy for mammals in relation to one another—rodents and primates, for example. So

90-474: Is an internal clade of the family. Dilkes and Arcucci (2012) combined data from several phylogenetic analyses of the Archosauriformes, such as Dilkes and Sues (2009), Ezcurra et al. (2010) and Nesbitt (2011), and added ten new characters to their matrix. The monophyly of Proterochampsia, which was restricted to proterochampsids, was supported by 12 unambiguous synapomorphies in their analysis, including

105-550: The Ancient Greek words σύν ( sún ), meaning "with, together"; ἀπό ( apó ), meaning "away from"; and μορφή ( morphḗ ), meaning "shape, form". Lampreys and sharks share some features, like a nervous system, that are not synapomorphic because they are also shared by invertebrates . In contrast, the presence of jaws and paired appendages in both sharks and dogs, but not in lampreys or close invertebrate relatives, identifies these traits as synapomorphies. This supports

120-456: The quadratojugal , a bone positioned toward the back of the skull behind the jugal. There is also a depression on the squamosal bone of the skull roof . The second metatarsal of the foot is wider than the other metatarsals. Proterochampsians lack a fifth digit on the foot; the fifth metatarsal is reduced to a small pointed bone. However, Nesbitt (2011) only considered Proterochampsia to include Proterochampsidae . Ezcurra (2016), who recovered

135-531: The concept can be understood as well in terms of "a character newer than" ( autapomorphy ) and "a character older than" ( plesiomorphy ) the apomorphy: mammary glands are evolutionarily newer than vertebral column, so mammary glands are an autapomorphy if vertebral column is an apomorphy, but if mammary glands are the apomorphy being considered then vertebral column is a plesiomorphy. These phylogenetic terms are used to describe different patterns of ancestral and derived character or trait states as stated in

150-496: The fifth digit but with a poorly developed first phalanx, among other traits. One of the earliest phylogenies of proterochampsians was proposed by Kischlat and Schultz (1999). They considered Proterochampsia as a substitute name for Proterochampsidae , and recovered a monophyletic Rhadinosuchidae within this clade. However, more recent studies regard Proterochampsidae as the appropriate name for this clade (since no doswelliids were included), and use Rhadinosuchinae instead, as it

165-510: The hypothesis that dogs and sharks are more closely related to each other than to lampreys. The concept of synapomorphy depends on a given clade in the tree of life. Cladograms are diagrams that depict evolutionary relationships within groups of taxa. These illustrations are accurate predictive device in modern genetics. They are usually depicted in either tree or ladder form. Synapomorphies then create evidence for historical relationships and their associated hierarchical structure. Evolutionarily,

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180-408: The inclusion of Doswelliidae in it is dependent upon whether Doswellia and Proterochampsa form a monophyletic group to the exclusion of Archosauria and other related groups. Nesbitt (2011) found that Proterochampsians share several distinguishing characteristics, or synapomorphies . A prominent ridge runs along the length of the jugal , a bone below the eye. Another ridge is present on

195-834: The node Tropidosuchus + Chanaresuchus . Trotteyn and Haro (2012) conducted a phylogenetic analysis of proterochampsians and other basal archosauriforms using only braincase characters, and found Doswellia , an unusual long-necked, heavily armored archosauriform from Virginia, to nest within Proterochampsia. A close relationship between Doswellia and proterochampsids was also found by Benton and Clark (1988) and Dilkes and Sues (2009). Trotteyn and Haro (2012) considered Proterochampsia to include proterochampsids and Doswellia , and proterochampsids to include all proterochampsians more closely related to Proterochampsa than to Doswellia . Ezcurra (2016) combined data several sets, including Nesbitt (2011) and Trotteyn and Haro (2012), and recovered

210-492: The presence of erect gait , fur , the evolution of three middle ear bones , and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles , which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. The word synapomorphy —coined by German entomologist Willi Hennig —is derived from

225-432: The presence of dermal sculpturing on skull that consists of prominent ridges or tubercles on frontals, parietals and nasals; a contact between the maxilla and the prefrontal, separating lacrimal and nasal; a strongly convex dorsal margin of surangular and palatal teeth that are inserted into alveoli. Some of the synapomorphies recovered by Nesbitt (2011) were found to support either the node Cerritosaurus + Chanaresuchus or

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