Proterosuchus

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Proterosuchus
Temporal range: Early Triassic, 252–250  Ma
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Proterosuchus fergusi 43.jpg
Skull of P. fergusi
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Family:† Proterosuchidae
Genus:† Proterosuchus
Broom, 1903
Type species
†Proterosuchus fergusi
Broom, 1903
Species
  • †Proterosuchus alexanderi(Haughton, 1965)
  • †Proterosuchus fergusiBroom, 1903
  • †Proterosuchus goweriEzcurra & Butler, 2015
Synonyms
  • ChasmatosaurusHaughton, 1924
  • Elaphrosuchus Broom, 1946

Proterosuchus is an extinct genus of archosauriform reptiles that lived during the Early Triassic. It contains three valid species: the type species P. fergusi and the referred species P. alexanderi and P. goweri. All three species lived in what is now South Africa. The genus was named in 1903 by the South African paleontologist Robert Broom. The genus Chasmatosaurus is a junior synonym of Proterosuchus.

Contents

Proterosuchus was a mid-sized quadrupedal reptile with a sprawling stance that could reach a length of up to 3.5 meters (11 ft). It had a large head and distinctively hooked snout. It was a predator, which may have hunted prey such as Lystrosaurus . The lifestyle of Proterosuchus remains debated; it may have been terrestrial or it may have been a semiaquatic ambush predator similar to modern crocodiles.

Proterosuchus is one of the earliest members of the clade Archosauriformes, which also includes crocodilians, pterosaurs, and dinosaurs, including birds. It lived in the aftermath of the Permian–Triassic extinction event, the largest known mass extinction in the timeline of Earth's history.

Description

Size of P. fergusi compared to a human Proterosuchus Scale.svg
Size of P. fergusi compared to a human

Proterosuchus was a quadrupedal reptile with a sprawling stance. [1] It could reach a total length of up to 3.5 meters (11 ft). [2] Proterosuchus fergusi is the largest known proterosuchid with a skull length of 47.7 cm (18.8 in) and a possible body length of 3.5–4 m (11–13 ft). [3] Like most reptiles, Proterosuchus had scaly skin. [4]

Proterosuchus had a proportionally large head and long neck compared to its body. [5] [6] The most distinctive characteristic of its head was its strongly hooked snout, formed by a downturned premaxilla. [7] The premaxilla contained up to nine teeth in adults, and the teeth in the snout tip were splayed out to the sides. [7] The jaws of Proterosuchus contained numerous teeth, with up to 9 premaxillary, 31 maxillary, and 28 dentary teeth in each side. [8] The teeth of Proterosuchus were recurved, labiolingually compressed, and serrated, as in most archosauriforms. They were isodont, or all equal in size and shape, in adult individuals, but in juveniles, the teeth were less strongly curved in the back of the jaw. [8]

The skull of Proterosuchus exhibits many features characteristic of its position as a basal archosauriform. It bears a prominent antorbital fenestra, like most archosauriforms. In some specimens, the jugal and quadratojugal contact to complete the ventral margin of the lower temporal fenestra, as in other archosauriforms, but in other specimens, there is a narrow gap between the bones so that the lower temporal bar is incomplete as in non-archosauriform archosauromorphs. [2] The lower jaw bears a small external mandibular fenestra, another characteristic of archosauriforms and their closest relatives. [9]

Classification

Life reconstruction of P. fergusi Proterosuchus BW.jpg
Life reconstruction of P. fergusi

Allokotosauria

Phylogenetic position of Proterosuchus within Crocopoda [10] [11]

Proterosuchus is an early member of Archosauriformes, which also contains crocodilians, pterosaurs, and dinosaurs, including birds. It is the type genus of Proterosuchidae, which also contains the genus Archosaurus . Proterosuchidae is, by definition, the most basal clade of archosauriforms, as Archosauriformes is defined based on their phylogenetic position. [12] Under pre-cladistic taxonomy, Proterosuchus was classified in the order Thecodontia and suborder Proterosuchia. Both taxa are now recognized as paraphyletic groups of basal archosauriforms.

Ezcurra et al. (2023) recovered Proterosuchus as the most basal member of the family Proterosuchidae, and the only definitive proterosuchid to not be a member of the subfamily Chasmatosuchinae. As Chasmatosuchinae contains the Permian Archosaurus , this would suggest that the ancestor of Proterosuchus diverged from other proterosuchids during the Permian. [13]

Species

Valid species

Proterosuchus currently contains three valid species, all from the Lower Triassic of South Africa.

  • Proterosuchus fergusi is the type species of Proterosuchus. It was named in 1903 by Robert Broom based on a specimen from Tarkastad donated by John Fergus, for whom the species was named. [14] It is known from several specimens, and the species Chasmatosaurus vanhoepeni and Elaphrosuchus rubidgei are junior synonyms of it. The holotype is poorly preserved and indeterminate, and a neotype has been suggested. It is distinguished from other species of Proterosuchus by its more strongly curved quadrate. [2]
  • Proterosuchus alexanderi was named by A. Hoffmann in 1965 based on a subadult specimen. [15] [8] It is currently only known from one specimen. [2] It is distinguished from other species of Proterosuchus by its longer snout. [2]
  • Proterosuchus goweri was named by Martín D. Ezcurra and Richard J. Butler in 2015, based on a specimen that had originally been described as a specimen of Chasmatosaurus vanhoepeni. [2] It is currently only known from one specimen. [2] It is distinguished from other species of Proterosuchus by a deep horizontal process of the maxilla, a sinusoidal ventral margin of the maxilla, and a gap in the tooth row between the premaxilla and maxilla. [2]

Other species

Life reconstruction of "Chasmatosaurus" yuani Chasmatosaurus BW.jpg
Life reconstruction of "Chasmatosaurus" yuani

Several species have been assigned to Proterosuchus or its junior synonym Chasmatosaurus in the past that are either no longer valid or no longer assigned to Proterosuchus.

  • Ankistrodon indicus was named in 1865 by Thomas Henry Huxley, based on a specimen from the Induan-age Panchet Formation of India. [16] [10] Ankistrodon has been regarded as a synonym of Proterosuchus or Chasmatosaurus in the past, but if this synonymy were correct, Ankistrodon would have priority over the other names. [17] It is now considered a nomen dubium. [17] [10]
  • Chasmatosaurus vanhoepeni is the type species of Chasmatosaurus. It was named in 1924 by Haughton. [18] The species name honors E. C. N. van Hoepen, who collected and prepared the holotype. [18] It is now considered a junior synonym of Proterosuchus fergusi. [2] Like all P. fergusi specimens, it is from the Lystrosaurus Assemblage Zone of the Beaufort Group of South Africa.
  • Chasmatosaurus yuani was named by C. C. Young in 1936, based on specimens from the Induan-age Jiucaiyuan Formation of China. [19] It is considered a valid species of proterosuchid, but is not formally assigned to Proterosuchus. [20] [10] It is considered to be in need of taxonomic revision. [20] It is more closely related to Proterosuchus goweri than to other species of Proterosuchus. [10]
  • Elaphrosuchus rubidgei was named by Robert Broom in 1946. [21] It is now considered a junior synonym of Proterosuchus fergusi, with the holotype being a juvenile specimen thereof. [2] Like all P. fergusi specimens, it is from the Lystrosaurus Assemblage Zone of the Beaufort Group of South Africa.
  • Chasmatosaurus ultimus was named by C. C. Young in 1964, based on a specimen from the Anisian-age Ermaying Formation of China. [22] [10] It was long believed to be the geologically youngest species of proterosuchid, as it would be the only one from the Middle Triassic. [17] [23] However, it is no longer considered to be a proterosuchid and is now considered to be a suchian archosaur. [10] [23] It is now considered a nomen dubium. [23]

Palaeobiology

Restoration of Lystrosaurus and P. fergusi Lystrosaurus murrayi and Proterosuchus fergusi.jpg
Restoration of Lystrosaurus and P. fergusi

The lifestyle of Proterosuchus is debated. It has conventionally been depicted as a semiaquatic ambush predator similar to modern crocodiles. However, it lived in an arid environment and many aspects of its anatomy conflict with a semiaquatic lifestyle. [24] In particular, its limbs are well-ossified, as in terrestrial animals, and the nostrils are laterally-positioned on the snout, not dorsally-positioned. The histology of its bones is reminiscent of terrestrial animals, not semiaquatic ones. [25] However, support for a semiaquatic lifestyle comes from its brain anatomy, which resembles semiaquatic predators such as crocodiles more closely than terrestrial reptiles. The orientation of its ear canals suggests its neutral head posture had the snout angled upward, which would have raised the nostrils high enough for the animal to breathe while largely submerged. [26] However, the utility of the orientation of the semicircular canal in determining head posture and habitat preference has been challenged. [27] Proterosuchus was a predator, but the specifics of its diet are not known. It has been suggested to have eaten fish or the abundant contemporary dicynodont Lystrosaurus . [24]

Snout function

The function of the hooked snout in Proterosuchus is not fully known. The most likely use was in sexual or social signaling, similar to the hooked snout of male salmon. As the snout does not appear to have been sexually dimorphic, it may be an example of mutual sexual selection. The snout may have been used in a specialized method of predation, as it exhibits high resistance to dorsoventral bending. [26] However, what this method may have been is unclear. The premaxillary teeth do not show wear facets and did not occlude with the teeth of the lower jaw, indicating that they were not used in any abrasive activities and could not have been used to grip prey. The snout tip did not have the pressure receptors present in crocodilians and Spinosaurus . [7]

Senses

P. fergusi skull diagram Proterosuchus fergusi skull.png
P. fergusi skull diagram

Proterosuchus had mesopic vision, indicating that it was adapted to see well in both bright and dim light. Mesopic vision is characteristic of cathemeral animals, which are active in both night and day, and crepuscular animals, which are active in twilight. Adaptations to see in dim light may have been ancestral to archosaurs, and Proterosuchus may have been an early example of this trend. [28] However, Proterosuchus lived near the Antarctic Circle, so its mesopic vision may have instead been an adaptation to the highly seasonal day lengths it experienced. [29] The hearing of Proterosuchus was likely adapted for lower frequencies, as in modern crocodiles. Due to its low-sensitivity hearing, Proterosuchus probably did not rely heavily on vocal communication and may have been relatively solitary. Based on the size of its olfactory bulbs, Proterosuchus had a strong sense of smell, similar to that of modern crocodiles. However, its olfactory bulbs were not as large as those of its relative Tasmaniosaurus , suggesting different habits and potentially a more aquatic ecology in Proterosuchus. [26]

Metabolism

The metabolism of Proterosuchus is disputed. Like other crocopod archosauromorphs, Proterosuchus had a higher metabolic rate than extant ectotherms. [30] Furthermore, Proterosuchus possessed fibrolamellar bone, indicative of a high growth rate and corresponding high metabolism. [25] [31] However, studies conflict on whether the metabolism of Proterosuchus was within the range of extant endotherms. [31] Its metabolic rate was lower than most other crocopods, except for the ectothermic phytosaurs and crocodilians, which may have been an adaptation to a crocodile-like predatory strategy. [30]

Ontogeny

Skull in Iziko South African Museum Iziko fossil crocodile head.JPG
Skull in Iziko South African Museum

Proterosuchus grew quickly. It probably reached sexual maturity within a year, at roughly two-thirds of its maximum adult body size. [8] Rapid growth rates were typical of Early Triassic archosauromorphs, and may have been an adaptation to surviving the hostile environment of the Early Triassic. [25] Juvenile Proterosuchus may have hunted different prey from adults. [8]

Palaeoecology

Proterosuchus fossils are found in the Lystrosaurus Assemblage Zone of the Beaufort Group in South Africa. Proterosuchus was the first new species to arrive in the Karoo environment after the Permian–Triassic extinction. Proterosuchus and the therocephalian Moschorhinus were the largest carnivores in the ecosystem at the time, and soon after the extinction Moschorhinus declined and went extinct while Proterosuchus thrived. [32] The most common tetrapod in Proterosuchus's environment was the herbivorous dicynodont Lystrosaurus . The environment was hot, semi-arid and experienced droughts. [33]

Related Research Articles

<span class="mw-page-title-main">Archosauriformes</span> Clade of reptiles

Archosauriformes is a clade of diapsid reptiles encompassing archosaurs and some of their close relatives. It was defined by Jacques Gauthier (1994) as the clade stemming from the last common ancestor of Proterosuchidae and Archosauria. Phil Senter (2005) defined it as the most exclusive clade containing Proterosuchus and Archosauria. Archosauriforms are a branch of archosauromorphs which originated in the Late Permian and persist to the present day as the two surviving archosaur groups: crocodilians and birds.

<span class="mw-page-title-main">Archosauromorpha</span> Infraclass of reptiles

Archosauromorpha is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs rather than lepidosaurs. Archosauromorphs first appeared during the late Middle Permian or Late Permian, though they became much more common and diverse during the Triassic period.

<i>Chasmatosuchus</i> Extinct genus of reptiles

Chasmatosuchus was an archosauriform reptile from the early Triassic period of European Russia. One of the earliest described archosauriforms, it was over 2 m long and is thought to have behaved like a modern crocodile. Its mouth had two distinct features: the top of its jaw hooked downwards to aid in holding prey, and the upper palate was lined with a row of teeth—a primitive feature lost in later archosaurs.

<span class="mw-page-title-main">Erythrosuchidae</span> Family of reptiles

Erythrosuchidae are a family of large basal archosauriform carnivores that lived from the later Early Triassic (Olenekian) to the early Middle Triassic (Anisian).

<span class="mw-page-title-main">Proterosuchidae</span> Extinct family of reptiles

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. The name comes from Greek πρότερο- ("first") and σοῦχος ("crocodile").

<i>Garjainia</i> Extinct genus of reptiles

Garjainia is an extinct genus of erythrosuchid archosauriform reptile from the Olenekian of Russia and South Africa. It was approximately 1.5–2 metres (4.9–6.6 ft) long. It contained two species, Garjainia prima from the Yarengian/Yarkenskian Supergorizont of Russia, and Garjainia madiba from the Burgersdorp Formation of South Africa. "Vjuskovia triplicostata", a name assigned to some erythrosuchid fossils from Russia, has been synonymized with Garjainia prima.

<i>Tasmaniosaurus</i> Extinct genus of reptiles

Tasmaniosaurus is an extinct genus of archosauromorph reptile known from the Knocklofty Formation of West Hobart, Tasmania, Australia. The type species is T. triassicus. This genus is notable not only due to being one of the most complete Australian Triassic reptiles known, but also due to being a very close relative of Archosauriformes. Once believed to be a proterosuchid, this taxon is now believed to have been intermediate between advanced non-archosauriform archosauromorphs such as Prolacerta, and basal archosauriforms such as Proterosuchus. Features traditionally used to define Archosauria and later Archosauriformes, such as the presence of an antorbital fenestra and serrated teeth, are now known to have evolved prior to those groups due to their presence in Tasmaniosaurus.

<i>Kalisuchus</i> Extinct genus of reptiles

Kalisuchus was a genus of basal archosauriform known from remains unearthed from the Arcadia Formation of the Early Triassic of the Crater, Southwest of Rolleston, south central Queensland, Australia. It was named after Kali, the Hindu goddess of destruction, a reference to the very fragmentary nature of its remains. The type species of Kalisuchus is K. rewanensis, which refers to the Rewan Group. The Arcadia formation is dated to the Induan age at the very beginning of the Triassic, making Kalisuchus one of the oldest archosauromorphs known in Australia.

<span class="mw-page-title-main">Proterochampsidae</span> Extinct family of reptiles

Proterochampsidae is a family of proterochampsian archosauriforms. Proterochampsids may have filled an ecological niche similar to modern crocodiles, and had a general crocodile-like appearance. They lived in what is now South America in the Middle and Late Triassic.

<i>Archosaurus</i> Extinct genus of reptiles

Archosaurus is an extinct genus of carnivorous proterosuchid archosauriform reptile. Its fossils are dated to the latest Permian of Russia and Poland, it is one of the earliest known archosauriforms. The type and only species is Archosaurus rossicus, known from several fragmentary specimens which cumulatively represent parts of the skull and cervical vertebrae. It would have been 3 metres (9.8 ft) long when fully grown.

Jaikosuchus is an extinct genus of proterosuchid archosauriform. It contains a single species, J. magnus. Fossils have been found from European Russia that date back to the upper Olenekian stage of the Early Triassic.

Tsylmosuchus is an extinct genus of proterosuchid archosauriform reptile known from Western Russia. Fossils referred to Tsylmosuchus occurred over a wide area in sediments corresponding to the Induan and Olenekian stages of the Early Triassic. Most of these fossils are fragmentary neck vertebrae which were originally reported as sharing similarities with crocodile-line archosaurs (pseudosuchians) such as Mandasuchus. As a result, Tsylmosuchus was first described as part of the family Rauisuchidae, making it supposedly one of the oldest known archosaurs. However, its fragmentary remains do not show any of the distinguishing features of rauisuchids or even pseudosuchians in general, so Tsylmosuchus has more recently been interpreted as an indeterminate archosauriform. Although three species of Tsylmosuchus have been named, they lack diagnostic traits and are probably not distinct from each other. In 2023, Tsylmosuchus was reinterpreted as a proterosuchid, specifically a member of the subfamily Chasmatosuchinae.

<span class="mw-page-title-main">Doswelliidae</span> Extinct family of reptiles

Doswelliidae is an extinct family of carnivorous archosauriform reptiles that lived in North America and Europe during the Middle to Late Triassic period. Long represented solely by the heavily-armored reptile Doswellia, the family's composition has expanded since 2011, although two supposed South American doswelliids were later redescribed as erpetosuchids. Doswelliids were not true archosaurs, but they were close relatives and some studies have considered them among the most derived non-archosaurian archosauriforms. They may have also been related to the Proterochampsidae, a South American family of crocodile-like archosauriforms.

Vonhuenia is an extinct genus of proterosuchid, a basal archosauriform from the Early Triassic of Russia. Fossils have been found in the Vokhminskaya Formation, along the Vetluga River that are Induan in age, making Vonhuenia one of the earliest archosauriforms.

<i>Prolacerta</i> Extinct genus of reptile from the lower Triassic

Prolacerta is a genus of archosauromorph from the lower Triassic of South Africa and Antarctica. The only known species is Prolacerta broomi. The generic name Prolacerta is derived from Latin meaning “before lizard” and its species name broomi is in commemoration of the famous paleontologist Robert Broom, who discovered and studied many of the fossils found in rocks of the Karoo Supergroup. When first discovered, Prolacerta was considered to be ancestral to modern lizards, scientifically known as lacertilians. However, a study by Gow (1975) instead found that it shared more similarities with the lineage that would lead to archosaurs such as crocodilians and dinosaurs. Prolacerta is considered by modern paleontologists to be among the closest relatives of the Archosauriformes.

Gamosaurus is an extinct genus of proterosuchid archosauriform. It contains a single species, Gamosaurus lozovskii, named by Vitalii Georgievich Ochev in 1979.

<i>Eorasaurus</i> Extinct genus of reptiles

Eorasaurus is an extinct genus of archosauromorph reptile known from the middle Late Permian of Tatarstan, European Russia. It contains a single species, Eorasaurus olsoni. When originally described by Sennikov (1997), Eorasaurus was identified as an early archosauromorph and assigned to the family Protorosauridae, Ezcurra et al. (2014) and Ezcurra (2016) later reclassified Eorasaurus and placed it within the group Archosauriformes. Eorasaurus is based solely on scant fossil material from the neck region, and is thus considered an unstable taxon in phylogenetic analyses. If Eorasaurus is an archosauriform, it would be the oldest known member of the group and would pre-date the previous record holder.

<i>Aenigmastropheus</i> Extinct genus of reptiles

Aenigmastropheus is an extinct genus of early archosauromorph reptiles known from the middle Late Permian Usili Formation of Songea District, southern Tanzania. It contains a single species, Aenigmastropheus parringtoni, known solely from UMZC T836, a partial postcranial skeleton of a mature individual. It was collected in 1933, and first described in 1956, as a "problematic reptile" due to its unique morphology. Therefore, a binomial name was erected for this specimen in 2014. Aenigmastropheus was probably fully terrestrial.

<i>Teyujagua</i> Extinct genus of reptiles

Teyujagua is an extinct genus of small, probably semi-aquatic archosauromorph reptile that lived in Brazil during the Early Triassic period. The genus contains the type and only known species, T. paradoxa. It is known from a well-preserved skull, and probably resembled a crocodile in appearance. It was an intermediary between the primitive archosauromorphs and the more advanced Archosauriformes, revealing the mosaic evolution of how the key features of the archosauriform skull were acquired. Teyujagua also provides additional support for a two-phase model of archosauriform radiation, with an initial diversification in the Permian followed by a second adaptive radiation in the Early Triassic.

Samsarasuchus is an extinct genus of archosauriform reptile from the Early Triassic of India. This genus has one known species, Samsarasuchus pamelae. Samsarasuchus lived a few million years after the Permian-Triassic extinction, the largest known mass extinction event. It was a member of the Proterosuchidae, a group of successful crocodile-like reptiles that survived the extinction event and were among the earliest successful archosauromorphs.

References

  1. ↑ Sullivan, Corwin (2015). "Evolution of hind limb posture in Triassic archosauriforms". In Dial, Kenneth P.; Shubin, Neil; Brainerd, Elizabeth L. (eds.). Great Transformations in Vertebrate Evolution. University of Chicago Press.
  2. 1 2 3 4 5 6 7 8 9 10 Ezcurra, Martín D.; Butler, Richard J. (2015). "Taxonomy of the proterosuchid archosauriforms (Diapsida: Archosauromorpha) from the earliest Triassic of South Africa, and implications for the early archosauriform radiation". Palaeontology. 58 (1): 141–170. doi:10.1111/pala.12130. S2CID   84348015.
  3. ↑ 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.{{cite book}}: CS1 maint: multiple names: authors list (link)
  4. ↑ Thornley, A. L. (1970). "Epidermal remnants of Proterosuchus vanhoepeni". Palaeontologia Africana. 13: 57–60.
  5. ↑ Butler, Richard J.; Sennikov, Andrey G.; Dunne, Emma M.; Ezcurra, Martin D.; Hedrick, Brandon P.; Maidment, Susannah C. R.; Meade, Luke E.; Raven, Thomas J.; Gower, David J. (2019). "Cranial anatomy and taxonomy of the erythrosuchid archosauriform 'Vjushkovia triplicostata' Huene, 1960, from the Early Triassic of European Russia". Royal Society Open Science. 6 (11): 191289. Bibcode:2019RSOS....691289B. doi:10.1098/rsos.191289. PMC   6894557 . PMID   31827861.
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  8. 1 2 3 4 5 Ezcurra, Martín D.; Butler, Richard J. (2015). "Post-hatchling cranial ontogeny in the Early Triassic diapsid reptile Proterosuchus fergusi". Journal of Anatomy. 226 (5): 387–402. doi: 10.1111/joa.12300 . PMC   4450940 . PMID   25913624.
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  10. 1 2 3 4 5 6 7 Ezcurra, Martín D. (2016). "The phylogenetic relationships of basal archosauromorphs, with an emphasis on the systematics of proterosuchian archosauriforms". PeerJ. 4: e1778. doi: 10.7717/peerj.1778 . PMC   4860341 . PMID   27162705.
  11. ↑ Pinheiro, Felipe L.; de Simão-Oliveira, Daniel; Butler, Richard J. (2019). "Osteology of the archosauromorph Teyujagua paradoxa and the early evolution of the archosauriform skull". Zoological Journal of the Linnean Society. 189: 378–417. doi: 10.1093/zoolinnean/zlz093 .
  12. ↑ Nesbitt, Sterling J. (2011). "The early evolution of archosaurs: relationships and the origin of major clades". Bulletin of the American Museum of Natural History. 352: 1–292. doi: 10.1206/352.1 . S2CID   83493714.
  13. ↑ Ezcurra, 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). doi:10.1098/rsos.230387. ISSN   2054-5703. PMC   10598453 . PMID   37885992.
  14. ↑ Broom, R. (1903). "On a new reptile (Proterosuchus fergusi) from the Karroo beds of Tarkastad, South Africa". Annals of the South African Museum. 4: 159–164.
  15. ↑ Hoffmann, A.C. (1965). "On the discovery of a new thecodont from the Middle Beaufort Beds". Researches of the National Museum, Bloemfontein. 2: 33–40.
  16. ↑ Huxley, Thomas H. (1865). "On a collection of vertebrate fossils from the Panchet Rocks, Ranigunj, Bengal". Memoirs of the Geological Survey of India.
  17. 1 2 3 Charig, A. J.; Reig, O. A. (1970). "The classification of the Proterosuchia". Biological Journal of the Linnean Society. 2 (2): 125–171. doi:10.1111/j.1095-8312.1970.tb01708.x.
  18. 1 2 Haughton, S.H. (1924). "On a new type of thecodont from the Middle Beaufort Beds". Annals of the Transvaal Museum. 11: 93–97.
  19. ↑ Young, C. C. (1936). "On a new Chasmatosaurus from Sinkiang". Bulletin of the Geological Society of China. 15 (3): 291–311. doi:10.1111/j.1755-6724.1936.mp15003003.x.
  20. 1 2 Nesbitt, Sterling J.; Flynn, John J.; Pritchard, Adam C.; Parrish, J. Michael; Ranivoharimanana, Lovasoa; Wyss, André R. (2015). "Postcranial osteology of Azendohsaurus madagaskarensis (?Middle to Upper Triassic, Isalo Group, Madagascar) and its systematic position among stem archosaur reptiles". Bulletin of the American Museum of Natural History. 398: 1–126. doi:10.1206/amnb-899-00-1-126.1. S2CID   86289421.
  21. ↑ Broom, R. (1946). "A new primitive proterosuchid reptile". Annals of the Transvaal Museum. 20: 343–346.
  22. ↑ Young, C.-C. (1964). "The pseudosuchians in China". Palaeontologia Sinica, New Series C. 151 (19): 1–205.
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  24. 1 2 Ezcurra, Martín D.; Butler, Richard J.; Gower, David J. (2013). "'Proterosuchia': the origin and early history of Archosauriformes". Geological Society, London, Special Publications. 379 (1): 9–33. Bibcode:2013GSLSP.379....9E. doi:10.1144/SP379.11. S2CID   83614859.
  25. 1 2 3 Botha-Brink, Jennifer; Smith, Roger M. H. (2011). "Osteohistology of the Triassic archosauromorphs Prolacerta, Proterosuchus, Euparkeria, and Erythrosuchus from the Karoo Basin of South Africa". Journal of Vertebrate Paleontology. 31 (6): 1238–1254. doi:10.1080/02724634.2011.621797. JSTOR   41407682. S2CID   130744235.
  26. 1 2 3 Brown, Emily E.; Butler, Richard J.; Ezcurra, Martín D.; Bhullar, Bhart-Anjan S.; Lautenschlager, Stephan (2019). "Endocranial anatomy and life habits of the Early Triassic archosauriform Proterosuchus fergusi" (PDF). Palaeontology. 63 (2): 255–282. doi:10.1111/pala.12454. S2CID   204271968.
  27. ↑ Benoit, J.; Legendre, L. J.; Farke, A. A.; Neenan, J. M.; Mennecart, B.; Costeur, L.; Merigeaud, S.; Manger, P. R. (2020). "A test of the lateral semicircular canal correlation to head posture, diet and other biological traits in "ungulate" mammals". Scientific Reports. 10 (1): 19602. Bibcode:2020NatSR..1019602B. doi: 10.1038/s41598-020-76757-0 . PMC   7658238 . PMID   33177568.
  28. ↑ Chang, Belinda S. W.; Jönsson, Karolina; Kazmi, Manija A.; Donoghue, Michael J.; Sakmar, Thomas P. (2002). "Recreating a Functional Ancestral Archosaur Visual Pigment". Molecular Biology and Evolution. 19 (9): 1483–1489. doi: 10.1093/oxfordjournals.molbev.a004211 . PMID   12200476.
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  31. 1 2 Cubo, Jorge; Jalil, Nour-Eddine (2019). "Bone histology of Azendohsaurus laaroussii: Implications for the evolution of thermometabolism in Archosauromorpha" (PDF). Paleobiology. 45 (2): 317–330. doi:10.1017/pab.2019.13. S2CID   155782789.
  32. ↑ Smith, Roger; Botha, Jennifer (2005). "The recovery of terrestrial vertebrate diversity in the South African Karoo Basin after the end-Permian extinction". Comptes Rendus Palevol. 4 (6–7): 623–636. doi:10.1016/j.crpv.2005.07.005.
  33. ↑ Smith, Roger; Rubidge, Bruce; van der Walt, Merrill (2012). "Therapsid biodiversity patterns and paleoenvironments of the Karoo Basin, South Africa". In Anusuya Chinsamy-Turan (ed.). Forerunners of Mammals: Radiation, Histology, Biology. Bloomington: Indiana University Press. pp. 31–62. ISBN   978-0-253-35697-0.
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