Proterosuchus fergusi from the Early Triassic of South Africa
They were slender, medium-sized (about 1.5 m (4 ft 11 in) long, largest specimens reached 3.5–4 m (11–13 ft)[2]), long-snouted and superficially crocodile-like animals, although they lacked the armoured scutes of true crocodiles, and their skeletal features are much more primitive. The limbs are short and indicate a sprawling posture, like contemporary lizards but unlike most later archosaurs.
Their most characteristic feature is a distinct down-turning of the premaxilla (the front of the upper jaw, which overhangs the lower jaw).
Evolutionary historyedit
The terminal Permian catastrophe, which killed off 95% of all types of life, cleared the world of all large therapsids and allowed the proterosuchids to become the top predators. Within the space of five million years the proterosuchids had evolved to fill a wide variety of terrestrial and semi-aquatic niches.[3] The proterosuchids represent perhaps the earliest adaptive radiation of the archosaurs. They gave rise to the Erythrosuchidae some time in the Early Triassic.[citation needed]
A 2023 study recovered a majority of proterosuchids outside of Proterosuchus and Sarmatosuchus as belonging to a distinct subfamily, the Chasmatosuchinae. Chasmatosuchinae contains many Triassic proterosuchids in addition to the only Permian proterosuchid, Archosaurus; this would suggest that an initial taxonomic diversification of the Proterosuchidae (including an initial taxonomic divergence between Proterosuchus and chasmatosuchines) had already occurred in the Permian.[1]
Classificationedit
Phylogenyedit
Recent studies consider Proterosuchidae to be at least a partially paraphyletic grouping, meaning that it does not form a true clade with a single common ancestor and proterosuchids as its only descendants. Instead, they are a chain of successively basal archosauriforms.[4][5] Below is a cladogram from Ezcurra (2016), that reexamined all historical members of the "Proterosuchia" (a polyphyletic historical group including proterosuchids and erythrosuchids). The placement of fragmentary taxa that had to be removed to increase tree resolution are indicated by dashed lines (in the most derived position that they can be confidently assigned to). Taxa that are nomina dubia are indicated by the note "dubium". Bold terminal taxa are collapsed. Ezcurra (2016) recovered a monophyletic Proterosuchidae containing only Archosaurus and the species of Proterosuchus, however some species (e.g. Chasmatosuchus spp, Vonhuenia friedrichi) are too fragmentary to resolve whether they also fall into Proterosuchidae. Tasmaniosaurus, Fugusuchus, Sarmatosuchus, Cuyosuchus and the "Long Reef proterosuchid" (SAM P41754) on the other hand were recovered confidently outside of Proterosuchidae.[5]
^ abcdefgEzcurra, Martín D.; Bandyopadhyay, Saswati; Sengupta, Dhurjati P.; Sen, Kasturi; Sennikov, Andrey G.; Sookias, Roland B.; Nesbitt, Sterling J.; Butler, Richard J. (25 October 2023). "A new archosauriform species from the Panchet Formation of India and the diversification of Proterosuchidae after the end-Permian mass extinction". Royal Society Open Science. 10 (10). Bibcode:2023RSOS...1030387E. doi:10.1098/rsos.230387. ISSN 2054-5703. PMC10598453. PMID 37885992.
^Julia Brenda Desojo, Randall B. Irmis, Sterling J. Nesbitt (2013). Anatomy, Phylogeny and Palaeobiology of Early Archosaurs and Their Kin. Geological Society. p. 20. ISBN9781862393615. Retrieved 14 September 2022.{{cite book}}: CS1 maint: multiple names: authors list (link)
^"Archosauria: Archosauriformes". Palaeos. Retrieved 29 October 2014.
^Ezcurra, M.D.; Lecuona, A.; Martinelli, A. (2010). "A new basal archosauriform diapsid from the Lower Triassic of Argentina". Journal of Vertebrate Paleontology. 30 (5): 1433–1450. Bibcode:2010JVPal..30.1433E. doi:10.1080/02724634.2010.501446. S2CID 83826840.
^ abcEzcurra, M.D. (2016). The phylogenetic relationships of basal archosauromorphs, with an emphasis on the systematics of proterosuchian archosauriforms. PeerJ, e1778 [1]
proterosuchidae, early, family, basal, archosauriforms, whose, fossils, known, from, late, permian, early, triassic, highest, diversity, genera, known, from, european, russia, fossils, also, known, from, south, africa, india, china, australia, brazil, possibly. Proterosuchidae is an early family of basal archosauriforms whose fossils are known from the Late Permian and the Early Triassic The highest diversity of genera is known from European Russia but fossils are also known from South Africa India China Australia Brazil and possibly Argentina 1 The name comes from Greek protero first and soῦxos crocodile ProterosuchidsTemporal range Latest Permian to Latest Early Triassic 252 247 Ma PreꞒ Ꞓ O S D C P T J K Pg N Possible Middle Triassic records Restored skull of Archosaurus Scientific classification Domain Eukaryota Kingdom Animalia Phylum Chordata Class Reptilia Clade Archosauromorpha Clade Archosauriformes Family ProterosuchidaeHuene 1914 Genera Proterosuchus Koilamasuchus Sarmatosuchus Blomosuchus Ankistrodon Chasmatosuchinae Vonhuenia Jaikosuchus Gamosaurus Chasmatosuchus Tsylmosuchus Samsarasuchus Archosaurus Synonyms Proterosuchinae Huene 1914 Chasmatosauridae Haughton 1924 Chasmatosaurinae Haughton 1924 Pelycosimiidae Abel 1919 Contents 1 Description 2 Evolutionary history 3 Classification 3 1 Phylogeny 3 2 Genera 4 References 5 Further reading 6 External linksDescription edit nbsp Proterosuchus fergusi from the Early Triassic of South Africa They were slender medium sized about 1 5 m 4 ft 11 in long largest specimens reached 3 5 4 m 11 13 ft 2 long snouted and superficially crocodile like animals although they lacked the armoured scutes of true crocodiles and their skeletal features are much more primitive The limbs are short and indicate a sprawling posture like contemporary lizards but unlike most later archosaurs Their most characteristic feature is a distinct down turning of the premaxilla the front of the upper jaw which overhangs the lower jaw Evolutionary history editThe terminal Permian catastrophe which killed off 95 of all types of life cleared the world of all large therapsids and allowed the proterosuchids to become the top predators Within the space of five million years the proterosuchids had evolved to fill a wide variety of terrestrial and semi aquatic niches 3 The proterosuchids represent perhaps the earliest adaptive radiation of the archosaurs They gave rise to the Erythrosuchidae some time in the Early Triassic citation needed A 2023 study recovered a majority of proterosuchids outside of Proterosuchus and Sarmatosuchus as belonging to a distinct subfamily the Chasmatosuchinae Chasmatosuchinae contains many Triassic proterosuchids in addition to the only Permian proterosuchid Archosaurus this would suggest that an initial taxonomic diversification of the Proterosuchidae including an initial taxonomic divergence between Proterosuchus and chasmatosuchines had already occurred in the Permian 1 Classification editPhylogeny edit Recent studies consider Proterosuchidae to be at least a partially paraphyletic grouping meaning that it does not form a true clade with a single common ancestor and proterosuchids as its only descendants Instead they are a chain of successively basal archosauriforms 4 5 Below is a cladogram from Ezcurra 2016 that reexamined all historical members of the Proterosuchia a polyphyletic historical group including proterosuchids and erythrosuchids The placement of fragmentary taxa that had to be removed to increase tree resolution are indicated by dashed lines in the most derived position that they can be confidently assigned to Taxa that are nomina dubia are indicated by the note dubium Bold terminal taxa are collapsed Ezcurra 2016 recovered a monophyletic Proterosuchidae containing only Archosaurus and the species of Proterosuchus however some species e g Chasmatosuchus spp Vonhuenia friedrichi are too fragmentary to resolve whether they also fall into Proterosuchidae Tasmaniosaurus Fugusuchus Sarmatosuchus Cuyosuchus and the Long Reef proterosuchid SAM P41754 on the other hand were recovered confidently outside of Proterosuchidae 5 Prolacertidae SAM PK 591 Ankistrodon indicus dubium Blomosuchus georgii dubium Tasmaniosaurus triassicus Archosauriformes Chasmatosuchus Chasmatosuchus magnus Chasmatosuchus rossicus Gamosaurus lozovskii Chasmatosuchus vjushkovi Vonhuenia friedrichi Proterosuchidae Archosaurus rossicus Proterosuchus fergusi Proterosuchus alexanderi Proterosuchus goweri Proterosuchus yuani Eorasaurus olsoni Kalisuchus rewanensis Fugusuchus hejiapanensis Sarmatosuchus otschevi Cuyosuchus huenei Erythrosuchidae SAM P41754 Uralosaurus magnus Guchengosuchus shiguaiensis other erythrosuchids Eucrocopoda previously assigned to ProterosuchidaeThe following phylogeny for the Proterosuchidae sensu stricto was recovered by Ezcurra et al 2023 1 Proterosuchidae Proterosuchus Chasmatosaurus yuani Chasmatosuchinae Vonhuenia Jaikosuchus Gamosaurus Chasmatosuchus Tsylmosuchus Samsarasuchus Archosaurus Genera edit Genus 5 Status Age Location Description Images Ankistrodon nomen dubium Early Triassic India Archosaurus Valid Late Permian Changhsingian Russia nbsp Blomosuchus nomen dubium Early Triassic Induan Russia Chasmatosuchus Valid Early Triassic Russia nbsp Gamosaurus Valid 1 Early Triassic Russia Jaikosuchus Valid 1 Early Triassic Russia Koilamasuchus Disputed Middle Late Triassic Argentina Proterosuchus Valid Early Triassic South Africa nbsp Samsarasuchus Valid Early Triassic India Sarmatosuchus Disputed Early Triassic Russia nbsp Tsylmosuchus Valid 1 Early Triassic Russia Vonhuenia Valid 1 Early Triassic Induan RussiaReferences edit a b c d e f g Ezcurra Martin D Bandyopadhyay Saswati Sengupta Dhurjati P Sen Kasturi Sennikov Andrey G Sookias Roland B Nesbitt Sterling J Butler Richard J 25 October 2023 A new archosauriform species from the Panchet Formation of India and the diversification of Proterosuchidae after the end Permian mass extinction Royal Society Open Science 10 10 Bibcode 2023RSOS 1030387E doi 10 1098 rsos 230387 ISSN 2054 5703 PMC 10598453 PMID 37885992 Julia Brenda Desojo Randall B Irmis Sterling J Nesbitt 2013 Anatomy Phylogeny and Palaeobiology of Early Archosaurs and Their Kin Geological Society p 20 ISBN 9781862393615 Retrieved 14 September 2022 a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link Archosauria Archosauriformes Palaeos Retrieved 29 October 2014 Ezcurra M D Lecuona A Martinelli A 2010 A new basal archosauriform diapsid from the Lower Triassic of Argentina Journal of Vertebrate Paleontology 30 5 1433 1450 Bibcode 2010JVPal 30 1433E doi 10 1080 02724634 2010 501446 S2CID 83826840 a b c Ezcurra M D 2016 The phylogenetic relationships of basal archosauromorphs with an emphasis on the systematics of proterosuchian archosauriforms PeerJ e1778 1 Further reading editBenton M J 2000 Vertebrate Paleontology 2nd Ed 2004 3rd edition Blackwell Science Ltd Carroll R L 1988 Vertebrate Paleontology and Evolution WH Freeman amp Co External links edit nbsp Paleontology portal Proterosuchidae Proterosuchidae list of species Mikko s Phylogeny Archive Retrieved from https en wikipedia org w index php title Proterosuchidae amp oldid 1220037047, wikipedia, wiki, book, books, library,
