Sinophoneus

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Sinophoneus
Temporal range: Middle Permian (Roadian), 272–270  Ma
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Sinophoneus-Paleozoological Museum of China.jpg
Skull, Paleozoological Museum of China
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Synapsida
Clade: Therapsida
Suborder:† Dinocephalia
Family:† Anteosauridae
Genus:† Sinophoneus
Cheng and Ji, 1996
Species:
†S. yumenensis
Binomial name
†Sinophoneus yumenensis
Cheng and Ji, 1996
Synonyms
  • Stenocybus acidentatusCheng and Li, 1997

Sinophoneus is an extinct genus of carnivorous dinocephalian therapsid belonging to the family Anteosauridae. It lived 272 to 270 million years ago at the beginning of the Middle Permian (Lower Roadian) in what is now the Gansu Province in northern China. It is known by a skull of an adult individual (the holotype GMV1601), as well as by many skulls of juvenile specimens. The latter were first considered as belonging to a different animal, named Stenocybus, before being reinterpreted as immature Sinophoneus. Sinophoneus shows a combination of characters present in other anteosaurs. Its bulbous profile snout and external nostrils located in front of the canine are reminiscent of the basal anteosaur Archaeosyodon , while its massive transverse pterygoids processes with enlarged distal ends are more similar to the more derived anteosaurs Anteosaurus and Titanophoneus . First phylogenetic analyzes identified Sinophoneus as the most basal Anteosaurinae. A more recent analysis positioned it outside the Anteosaurinae and Syodontinae subclades, and recovers it as the most basal Anteosauridae.

Contents

Description

The holotype of Sinophoneus is a somewhat dorsoventrally deformed skull measuring 32 cm in length from the tip of the snout to the occipital condyle [1] and about 35 cm in total length to the posterior border of the squamosal. [2] The upper part of the orbits is crushed, giving them an oval shape. They had to be originally circular. Most of the temporal arches are missing, as is the dentition of the upper jaws. The lower jaw is not preserved. The skull is mainly characterized by the presence of a median ridge starting between the eye sockets (where it is poorly developed) and extending to the tip of the snout (where it is more robust) which it protrudes beyond in dorsal view. The nostrils are smaller than in other anteosaurs. As in Archaeosyodon , the nostrils are entirely located in front of the upper canine whereas in other anteosaurs they are mainly located above or behind the canine. The snout profile is bulbous as in Archaeosyodon. The transverse processes of the pterygoids have a very enlarged distal end giving them a palmate morphology in ventral view as in Anteosaurus and Titanophoneus . [2] [3] [1]

Synonymy with Stenocybus

Illustration of a juvenile Sinophoneus yumenensis based on the IGCAGS V 361 specimen which was the holotype of Stenocybus acidentatus. StenocybusDB.jpg
Illustration of a juvenile Sinophoneus yumenensis based on the IGCAGS V 361 specimen which was the holotype of Stenocybus acidentatus.
Restoration of adult Sinophoneus yumenensis Sinophoneus09.jpg
Restoration of adult Sinophoneus yumenensis

In 1997, Cheng & Li described the small dinocephalian Stenocybus acidentatus, from a complete skull (IGCAGS V 361) and jaw remains from a second specimen, found in the same site as Sinophoneus. Although in their article, Cheng and Li did not compare Stenocybus directly with Sinophoneus, they consider the first sufficiently different from Anteosauridae to place it in a new family, the Stenocybusidae. [4] The name of this clade was later correctly modified in Stenocybidae by the Russian paleontologist Mikhail Feodosievich Ivakhnenko. [5] The latter was also the first researcher to suggest that Stenocybus could be the juvenile form of Sinophoneus. [5] [6] In 2011, Christian Kammerer also considered Stenocybus as a young Sinophoneus, the proportions of the first (absence of pachyostosis, tall and narrow skull, relatively large orbits, and smaller temporal fenestra) being typical characters of juvenile therapids. In addition, the immature skull of Stenocybus already shows a beginning of the median ridge of the snout characteristic of Sinophoneus, as well as the same bulbous profile of the snout as in the latter. As a result, Kammerer regards Stenocybus acidentatus as a junior synonym of Sinophoneus yumenensis. [3] A conclusion shared by Liu and Li from new specimens mentioned in a short note published the same year. [7] In 2014, Jiang and Ji described two new specimens of Stenocybus: a snout with articulated jaws, and a right dentary with an almost complete dentition, belonging to two individuals slightly larger than the holotype. Although providing new information on the anatomy of the animal, such as the number of teeth on the mandible, Jiang and Ji believe that the phylogenetic position of Stenocybus remains difficult to confirm, and that the synonymy of Stenocybus with Sinophoneus proposed by Kammerer, Liu and Li must be proved by the discovery of more complete specimens. [8] However, Jiang and Ji's wishes had been realize a few months earlier. In 2013 Liu described the seven new skulls of Sinophoneus (including one associated with postcranial remains) that had only been mentioned in the short note of 2011. These skulls all belong to specimens smaller than the holotype, but they represent various ontogenetic stages. They confirm that the skulls of Stenocybus actually represent several juvenile stages of Sinophoneus. [1]

Ontogeny

The ontogenetic series of the genus Sinophoneus is incomplete with an unrepresented size range between the known juvenile skulls measuring between 12 and 18 cm in length and the only known adult skull measuring 32 cm. However, this ontogenetic series makes it possible to identify the important morphological changes between the juveniles and the adults of this genus. The skull of the juvenile is relatively tall and narrow, and pachyostosis is absent. In the adult, the skull becomes much wider and lower, notably the bones of the palate which widen considerably, and a pachyostosis is observed on the bones surrounding the orbits. The medial ridge on the skull roof is weak in the smallest known specimen, but a pair of bosses is present on the midline of the inter-orbital region. This ridge extends from the pineal foramen to a point slightly beyond the orbit in the juvenile. It is more pronounced in adults where it extends to the end of the snout that ends prominently. The nostrils and orbits increase only slightly in size during growth. In contrast, the dimensions of the temporal fenestrae increase dramatically. They are triangular in shape and much smaller than orbit in the smaller specimens, have a size close to that of the orbits in somewhat larger specimens, and are much larger than the orbit in the adult. The latter were therefore equipped with a mandibular adductor musculature much more developed than that of the juveniles, and could inflict proportionally much more powerful bites. These differences indicate that in Sinophoneus, juveniles and adults certainly occupied distinct ecological niches and did not covet the same preys. [1] This pattern is also known in the South African genus Anteosaurus. [9] [10]

Geographic and stratigraphic distribution

All fossils of Sinophoneus come from a single locality, the Dashankou site, near Yumen City, in western Gansu Province, China. Stratigraphically, they belong to the Qingtoushan Formation (which before 2012 was called the Xidagou Formation), [11] whose sediments are of fluvial origin. [12] No radiometric dating is known for the Qingtoushan Formation, but Liu et al. assigns it a lower Roadian age (lowermost Middle Permian), thus partially filling the Olson Gap. [12] [13] The latter corresponds to a period of time with a poor fossil record, located between the lower Permian, dominated by the pelycosaurs, and the mid-middle Permian (Wordian), where the therapids take the first place in terrestrial ecosystems. The Roadian age attributed to the Qingtoushan Formation is an estimate derived from the degree of evolution of the Dashankou fauna. This fauna is composed both of animals belonging to ancient lineages, rather typical of Upper Carboniferous and Lower Permian, such as the temnospondyl dissorophoid Anakamacops [14] and the Bolosauridae Belebey , [15] and also of more derived forms, rather typical of the middle and upper Permian , such as the anthracosaurs Chroniosuchidae Ingentidens and Phratochronis , [14] the moradisaurine Gansurhinus , [16] and several therapsids. The latter are, however, exclusively represented by phylogenetically basal taxa. These are Raranimus , the most basal therapid known to date, [12] [17] and Biseridens , the most basal anomodont. [18] [19] The new classification of Sinophoneus, identified by Liu as the most basal Anteosauridae, is an additional argument in favor of a Roadian age for the Dashankou fauna. [1] Moreover, the latter was correlated with the Russian Parabradysaurus silantjevi assemblage zone of Roadian age. [17] Coinciding with its basal phylogenetic position, the Lower Roadian age of Sinophoneus makes it one of the oldest known anteosaurs to date, together with the Russian genus Microsyodon being of comparable age. [20]

Classification and phylogeny

In 2011 Christian Kammerer published the first phylogenetic analysis including all anteosaurs. This one recognized the monophyly of Anteosauridae, which contain two main clades: Syodontinae and Anteosaurinae. Sinophoneus is identified as the most basal Anteosaurinae and is the sister group of an unresolved trichotomy including Titanophoneus potens, T. adamanteus and Anteosaurus. [3]

Below, the cladogram of the anteosaurs presented by Kammerer in 2011 : [3]

Therapsida

In describing the new Brazilian anteosaur Pampaphoneus , Cisneros et al. presented another cladogram confirming the recognition of the clades Anteosaurinae and Syodontinae. Sinophoneus occupies the same position there as in the cladogram proposed by Kammerer. [21]

The cladogram of Cisneros et al. published in the main paper and excluding the genus Microsyodon. [21]

Therapsida

One of the four cladograms of Cisneros et al. published in the Supporting Information of the same article, and including Microsyodon. [21]

Therapsida


In 2013, Jun Lui presented a new cladogram in which Sinophoneus is reinterpreted as the most basal anteosauridae and is thus excluded from Anteosaurinae. [1]

The cladogram published by Jun Liu in 2013 : [1]

Therapsida

Related Research Articles

<span class="mw-page-title-main">Therapsida</span> Clade of tetrapods including mammals

Therapsida is a clade composing of a major group of eupelycosaurian synapsids that includes mammals and their ancestors and close relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more underneath the body, as opposed to the sprawling posture of many reptiles and salamanders.

<span class="mw-page-title-main">Dinocephalia</span> Extinct clade of stem-mammals

Dinocephalians are a clade of large-bodied early therapsids that flourished in the Early and Middle Permian between 279.5 and 260 million years ago (Ma), but became extinct during the Capitanian mass extinction event. Dinocephalians included herbivorous, carnivorous, and omnivorous forms. Many species had thickened skulls with many knobs and bony projections. Dinocephalians were the first non-mammalian therapsids to be scientifically described and their fossils are known from Russia, China, Brazil, South Africa, Zimbabwe, and Tanzania.

<span class="mw-page-title-main">Anomodontia</span> Suborder of stem-mammals

Anomodontia is an extinct group of non-mammalian therapsids from the Permian and Triassic periods. By far the most speciose group are the dicynodonts, a clade of beaked, tusked herbivores. Anomodonts were very diverse during the Middle Permian, including primitive forms like Anomocephalus and Patranomodon and groups like Venyukovioidea and Dromasauria. Dicynodonts became the most successful and abundant of all herbivores in the Late Permian, filling ecological niches ranging from large browsers down to small burrowers. Few dicynodont families survived the Permian–Triassic extinction event, but one lineage (Kannemeyeriiformes) evolved into large, stocky forms that became dominant terrestrial herbivores right until the Late Triassic, when changing conditions caused them to decline, finally going extinct during the Triassic–Jurassic extinction event.

<i>Titanophoneus</i> Extinct genus of therapsids

Titanophoneus is an extinct genus of carnivorous dinocephalian therapsid from the Middle Permian. It is classified within the family Anteosauridae. The type species is Titanophoneus potens. Remains of Titanophoneus have been found at Isheevo, Russia.

<span class="mw-page-title-main">Anteosaur</span> Extinct clade of therapsids

Anteosaurs are a group of large, primitive carnivorous dinocephalian therapsids with large canines and incisors and short limbs, that are known from the Middle Permian of South Africa, Russia, China, and Brazil. Some grew very large, with skulls 50–80 centimetres (20–31 in) long, and were the largest predators of their time. They died out at the end of the Middle Permian, possibly as a result of the extinction of the herbivorous Tapinocephalia on which they may have fed.

<span class="mw-page-title-main">Anteosauridae</span> Extinct family of therapsids

Anteosauridae is an extinct family of large carnivorous dinocephalian therapsids that are known from the Middle Permian of Asia, Africa, and South America.These animals were by far the largest predators of the Permian period, with skulls reaching 80 cm in length in adult individuals, far larger than the biggest gorgonopsian.

<i>Anteosaurus</i> Extinct genus of anteosaurid synapsid from the Permian

Anteosaurus is an extinct genus of large carnivorous dinocephalian synapsid. It lived at the end of the Guadalupian during the Capitanian stage, about 265 to 260 million years ago in what is now South Africa. It is mainly known by cranial remains and few postcranial bones. Measuring 5–6 m (16–20 ft) long and weighing about 600 kg (1,300 lb), Anteosaurus was the largest known carnivorous non-mammalian synapsid and the largest terrestrial predator of the Permian period. Occupying the top of the food chain in the Middle Permian, its skull, jaws and teeth show adaptations to capture large prey like the giants titanosuchids and tapinocephalids dinocephalians and large pareiasaurs.

<i>Australosyodon</i> Extinct genus of therapsids

Australosyodon is an extinct genus of dinocephalian therapsids from the middle Permian of South Africa. The first fossil was discovered in the 1980s near the village of Prince Albert Road in the Karoo region of South Africa.

<i>Styracocephalus</i>

Styracocephalus platyrhynchus is an extinct genus of dinocephalian therapsid that existed during the mid-Permian throughout South Africa, but mainly in the Karoo Basin. It is often referred to by its single known species Styracocephalus platyrhynchus. The Dinocephalia clade consisted of the largest land vertebrates and herbivores during the early to mid-Permian. This period is often also referred to as the Guadalupian epoch, approximately 270 to 260 million years ago.

<i>Bullacephalus</i> Extinct genus of animal

Bullacephalus is an extinct genus of biarmosuchian therapsids belonging to the family Burnetiidae. The type species B. jacksoni was named in 2003. It is known from a relatively complete skull and lower jaw, discovered in the Late Permian Tapinocephalus Assemblage Zone of the Beaufort Group of South Africa. This genus of therapsida lived during the Late Permian period, approximately 250 million years ago. The name Bullacephalus comes from the Latin words "bullatus," meaning "bossed" or "knobbed," and "cephalus," meaning "head." This name refers to the distinctive bony knob on the top of the therapsid's skull, which contributes to the history of this genus. This stem based taxon includes Ictidorhinus or Hippasaurs. Bullacephalus can even be characterized as having a, “skull moderately to greatly pachyostotic; swollen boss present above the postorbital bar formed by the postfrontal and postorbital; deep linear sculpturing of the snout; exclusion of the jugal from the lateral temporal fenestra”. These Therapsids have spongy bone skull roof, palatal process of premaxilla are long, diverticulum of naris adding them to the Burnetiamorph. Furthermore, the discovery of Bullacephalus has helped to refine the taxonomic classification of therapsids. Prior to its discovery, there was uncertainty regarding the relationship between different groups of therapsids, particularly the Burnetiamorpha and the Biarmosuchia. However, the distinctive features of Bullacephalus suggest that it is a member of the Burnetiamorpha, and provides a bridge between this group and the Biarmosuchia. The discovery of Bullacephalus has also highlighted the importance of continued exploration and excavation in areas that have yielded few therapsid fossils. The Beaufort Group of South Africa, where Bullacephalus was discovered, has been an important site for therapsid fossils, but much of the area remains unexplored. Further discoveries in this region and other areas around the world may provide new insights into the evolution and diversification of therapsids, as well as other groups of extinct animals. These discoveries will also help to refine our understanding of the history of life on Earth and the processes that have shaped the diversity of organisms that exist today.

<i>Biseridens</i> Extinct genus of therapsids

Biseridens is an extinct genus of anomodont therapsid, and one of the most basal anomodont genera known. Originally known from a partial skull misidentified as an eotitanosuchian in 1997, another well-preserved skull was found in the Qingtoushan Formation in the Qilian Mountains of Gansu, China, in 2009 that clarified its relationships to anomodonts, such as the dicynodonts.

<i>Moschognathus</i> Extinct genus of therapsids that lived in the Guadalupian epoch

Moschognathus is an extinct genus of dinocephalian therapsid in the family Tapinocephalidae. The genus includes only the type species M. whaitsi, named by palaeontologist Robert Broom in 1914. It was a short-snouted tapinocephalid, closely related to and resembling the well-known genus Moschops, but its skull is less thickened overall has a relatively longer and shallower snout by comparison. Indeed, Moschognathus has typically been regarded as a junior synonym of Moschops since 1969 after Lieuwe Dirk Boonstra sunk Moschognathus into Moschops, albeit retained as its own doubtfully valid species. However, researchers in the 21st century have expressed doubt over this synonymy and suggested that Moschognathus is a distinct taxon after all, including first by Christian Kammerer in a 2009 Ph.D. thesis and formally in 2015 by Alessandra D. S. Boos and colleagues in 2015. Moschognathus has since began to re-enter scientific literature of dinocephalians as a valid name and treated distinct from Moschops.

<i>Raranimus</i> Extinct genus of therapsids

Raranimus is an extinct genus of therapsids of the Middle Permian. It was described in 2009 from a partial skull found in 1998 from the Dashankou locality of the Qingtoushan Formation, outcropping in the Qilian Mountains of Gansu, China. The genus is the most basal known member of the clade Therapsida, to which the later Mammalia belong.

<i>Criocephalosaurus</i> Extinct genus of therapsids

Criocephalosaurus is an extinct genus of tapinocephalian therapsids that lived in Southern Africa during the Guadalupian epoch of the Permian. They are the latest surviving dinocephalians, extending past the Abrahamskraal Formation into the lowermost Poortjie Member of the Teekloof Formation in South Africa. They are also regarded as the most derived of the dinocephalians, alongside Tapinocephalus, and the most abundant in the fossil record.

The Qingtoushan Formation is a Middle Permian-age geologic formation in the Qilian Mountains of Gansu, China. It is known for its diverse tetrapod fauna known as the Dashankou fauna, which likely dates to the Roadian, and includes some of the oldest known therapsids. This formation was previously erroneously named as the Xidagou Formation, a name which applies to otherwise Triassic strata in the northern Qillian Mountains. The formation is over 300 metres thick, and primarily consists of purple-red coarse sandstones, with minor purple mudstone.

Daqingshanodon is an extinct genus of dicynodont therapsid from the Late Permian of Inner Mongolia, China. The type species D. limbus was described in 1989 from a single skull found in the Naobaogou Formation. Daqingshanodon belongs to a group of dicynodonts called cryptodonts. It is the smallest known cryptodont, and the only one known from China. Like other cryptodonts, it has a pair of rounded nasal bosses above its nostrils and a ridge of bone on the upper jaw called the postcaniniform process. Daqingshanodon has a pair of elongated, recurved tusks extending from its beak-like snout. It is distinguished from other dicynodonts by the presence of a distinct ridge running along the side of the skull from below the eye socket to the area around the tusks. The skull of Daqingshanodon is less than 10 centimetres (3.9 in) long, yet this specimen is thought to have been an adult on the basis of its well-developed nasal bosses.

<i>Pampaphoneus</i> Extinct genus of therapsids

Pampaphoneus is an extinct genus of carnivorous dinocephalian therapsid belonging to the family Anteosauridae. It lived 268 to 265 million years ago during the Wordian age of the Guadalupian period in what is now Brazil. Pampaphoneus is known by an almost complete skull with the lower jaw still articulated, discovered on the lands of the Boqueirão Farm, near the city of São Gabriel, in the state of Rio Grande do Sul. A second specimen from the same locality was reported in 2019 and 2020 but has not yet been described. It is composed of a skull associated with postcranial remains. It is the first South American species of dinocephalian to have been described. The group was previously known in South America only by a few isolated teeth and a jaw fragment reported in 2000 in the same region of Brazil. Phylogenetic analysis conducted by Cisneros and colleagues reveals that Pampaphoneus is closely related to anteosaurs from European Russia, indicating a closer faunal relationship between South America and Eastern Europe than previously thought, thus promoting a Pangea B continental reconstruction.

<span class="mw-page-title-main">Syodontinae</span> Extinct subfamily of mammal ancestors

Syodontinae is a group of dinocephalian therapsids. It is one of two subfamilies in the family Anteosauridae, the other being Anteosaurinae. They are known from the Middle Permian Period of what is now Russia and South Africa. One of the best known syodontines is Syodon from Russia. The South African form Australosyodon, is one of the earliest known Gondwanan anteosaurs.

<span class="mw-page-title-main">Anteosaurinae</span> Extinct subfamily of therapsids

Anteosaurinae is an extinct subfamily of dinocephalian therapsids. It is one of two subfamilies in the family Anteosauridae, the other being Syodontinae.

Phorcys is an extinct genus of gorgonopsian that lived during the Middle Permian period (Guadalupian) of what is now South Africa. It is known from two specimens, both portions from the back of the skull, that were described and named in 2022 as a new genus and species P. dubei by Christian Kammerer and Bruce Rubidge. The generic name is from Phorcys of Greek mythology, the father of the Gorgons from which the gorgonopsians are named after, and refers to its status as one of the oldest representatives of the group in the fossil record. Phorcys was recovered from the lowest strata of the Tapinocephalus Assemblage Zone (AZ) of the Beaufort Group, making it one of the oldest known gorgonopsians in the fossil record—second only to fragmentary remains of an indeterminate gorgonopsian from the older underlying Eodicynodon Assemblage Zone.

References

  1. 1 2 3 4 5 6 7 Liu, J. (2013). "Osteology, Ontogeny, and Phylogenetic Position of Sinophoneus yumenensis (Therapsida, Dinocephalia) from the Middle Permian Dashankou Fauna of China". Journal of Vertebrate Paleontology. 33 (6): 1394–1407. doi:10.1080/02724634.2013.781505. S2CID   85577626.
  2. 1 2 Cheng, Z.-W.; Ji, S. (1996). "First record of a primitive anteosaurid dinocephalian from the Upper Permian of Gansu, China". Vertebrata PalAsiatica. 34 (2): 123–134.
  3. 1 2 3 4 Kammerer, C.F. (2011). "Systematics of the Anteosauria (Therapsida: Dinocephalia)". Journal of Systematic Palaeontology. 9 (2): 261–304. doi:10.1080/14772019.2010.492645. S2CID   84799772.
  4. ↑ Cheng, Z.-W.; Li, J.-L. (1997). "A new genus of primitive dinocephalian - the third report on Late Permian Dashankou lower tetrapod fauna". Vertebrata PalAsiatica. 35 (1): 35–43.
  5. 1 2 Ivakhnenko, M.F. (1999). "Biarmosuches from the Ocher faunal assemblage of eastern Europe". Paleontological Journal. 33 (3): 289–296.
  6. ↑ Ivakhnenko, M.F. (2003). "Eotherapsids from the East European Placket (Late Permian)". Paleontological Journal (37): 339–465.
  7. ↑ Liu, J.; Li, J. (2011). "Osteology and phylogenetic Position of Sinophoneus yumenensis (Therapsida, Dinocephalia) from the Dashankou Fauna (Middle Permian)" (PDF). 71st Annual Meeting Society of Vertebrate Paleontotology, November 2 – 5, 2011: 145.
  8. ↑ Jiang, S.; Ji, S. (2014). "New specimens of Stenocybus acidentatus (Therapsida: Dinocephalia) from the Middle Permian Dashankou fauna of China". Acta Geologica Sinica (English Edition). 88 (3): 730–737. doi:10.1111/1755-6724.12233. S2CID   128691778.
  9. ↑ Kruger, A. (2014). Ontogeny and cranial morphology of the basal carnivorous dinocephalian Anteosaurus magnificus from the tapinocephalus assemblage zone of the South African Karoo (MS dissertation). Johannesburg: University of the Witwatersrand.
  10. ↑ Kruger, A.; Rubidge, B.S.; Abdala, F. (2017). "A juvenile specimen of Anteosaurus magnificus Watson, 1921 (Therapsida: Dinocephalia) from the South African Karoo, and its implications for understanding dinocephalian ontogeny". Journal of Systematic Palaeontology. 16 (2): 139–158. doi:10.1080/14772019.2016.1276106. S2CID   90346300.
  11. ↑ Liu, J.; Sun, K.-Q.; Li, L. (2012). "The vertebrate fossil-bearing horizon in Yuman, Gansu and the Permian-Triassic strata in north Qilian area". Vertebrata PalAsiatica. 50 (4): 373–381.
  12. 1 2 3 Liu, J.; Rubidge, B.S.; Li, J. (2009). "New basal synapsid supports Laurasian origin for therapsids" (PDF). Acta Palaeontologica Polonica. 54 (3): 393–400. doi: 10.4202/app.2008.0071 . S2CID   55062279.
  13. ↑ Liu, J. (2010). "Dashankou Fauna : A Unique Window on the Early Evolution of Therapsids" (PDF). Bulletin of the Chinese Academy of Science. 24 (2): 83–85.
  14. 1 2 Li, J.; Cheng, Z. (1999). "New Anthracosaur and Temnospondyl Amphibians from Gansu, China – The Fifth Report on Late Permian Dashankou Lower Tetrapod Fauna". Vertebrata PalAsiatica. 37 (3): 234–247.
  15. ↑ Müller, J.; Li, J.-L.; Reisz, R.R. (2008). "A new bolosaurid parareptile, Belebey chengi sp. nov., from the Middle Permian of China and its paleogeographic significance". Naturwissenschaften. 95 (12): 1169–1174. Bibcode:2008NW.....95.1169M. doi:10.1007/s00114-008-0438-0. PMID   18726080. S2CID   34304658.
  16. ↑ Reisz, R.R.; Liu, J.; Li, J.-L.; Müller, J. (2011). "A new captorhinid reptile, Gansurhinus qingtoushanensis, gen. et sp. nov., from the Permian of China". Naturwissenschaften. 90 (5): 435–441. Bibcode:2011NW.....98..435R. doi:10.1007/s00114-011-0793-0. PMID   21484260. S2CID   20274349.
  17. 1 2 Duhamel, A.; Benoit, J.; Rubidge, B.S.; Liu, J. (2021). "A re-assessment of the oldest therapsid Raranimus confirms its status as a basal member of the clade and fills Olson's gap". The Science of Nature. 108 (26): 26. Bibcode:2021SciNa.108...26D. doi:10.1007/s00114-021-01736-y. PMID   34115204. S2CID   235403632.
  18. ↑ Li, J.; Cheng, Z. (1997). "First discovery of eotitanosuchian (Therapsida, Synapsida) of China". Vertebrata PalAsiatica. 35 (4): 268–282.
  19. ↑ Liu, J.; Rubidge, B.; Li, J. (2010). "A new specimen of Biseridens qilianicus indicates its phylogenetic position as the most basal anomodont". Proceedings of the Royal Society B. 277 (1679): 285–292. doi:10.1098/rspb.2009.0883. PMC   2842672 . PMID   19640887.
  20. ↑ Golubev, V.K. (2015). "Dinocephalian Stage in the History of the Permian Tetrapod Fauna of Eastern Europe". Paleontological Journal. 49 (12): 1346–1352. doi:10.1134/S0031030115120059. S2CID   130694755.
  21. 1 2 3 Cisneros, J.C.; Abdala, F.; Atayman-Güven, S.; Rubidge, B.S.; Şengör, A.M.C.; Schultz, C.L. (2012). "Carnivorous dinocephalian from the Middle Permian of Brazil and tetrapod dispersal in Pangaea" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 109 (5): 1584–1588. Bibcode:2012PNAS..109.1584C. doi: 10.1073/pnas.1115975109 . PMC   3277192 . PMID   22307615.
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