Cistecephalidae

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Cistecephalidae
Temporal range: Late Permian
Cistecephalus1DB.jpg
Reconstruction of Cistecephalus microrhinus
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Synapsida
Clade: Therapsida
Suborder: Anomodontia
Clade: Dicynodontia
Clade: Kistecephalia
Family: Cistecephalidae
Broom, 1913
Genera

Cistecephalidae is an extinct family of dicynodont therapsids from the Late Permian of South Africa, India and Zambia. It includes the genera Cistecephalus , Cistecephaloides , and Kawingasaurus . [1] Cistecephalids are thought to have had a fossorial or burrowing lifestyle, with adaptations such as broad skulls, strong forelimbs, and squat bodies. A similar group of dicynodonts called the pylaecephalids were also fossorial, although to a lesser extent than cistecephalids. [2] Cistecephalids showed a high level of endemism, with each of the five known species unique to a single region. [3]

Contents

Description

Cistecephalids were small dicynodonts. Most species, with the exception of Kembawacela , lacked tusks, but sexually dimorphic supraorbital ridges were present. [3] [4] Cistecephalids had boxy, broad skulls with relatively laterally directed temporal openings, a result of a considerably broadened intertemporal region. Sauroscaptor, the most basal genus of the family, had a less extreme broadening of the intratemporal region than in other members of the family. [3] In the derived genera Cistecephaloides and Kawingasaurus, the intratemporal portion of the skull was broader than the skull was long. Cistecephalids also had a relatively posteriorly positioned pineal foramen, which in Kembawacela and Sauroscaptor was displaced all the way to the posterior margin of the skull. They also had anteriorly directed orbits; they may have had binocular vision, which may have been an adaptation for nocturnality or an insectivorous lifestyle. [4]

Classification

The Cistecephalidae contains five named genera each with one species. It is a member of the Dicynodont clade Emydopoidea. Phylogeny following Kammerer et al. 2016: [1] [3]

Related Research Articles

<i>Cistecephalus</i> Extinct genus of dicynodonts

Cistecephalus is an extinct genus of dicynodont therapsid from the Late Permian of southern Africa. It was a small, specialised, burrowing dicynodont, possibly with habits similar to a modern mole. The head was flattened and wedge-shaped, the body long, and the forelimbs very strong, with similarities in structure to the forelimb of modern burrowing mammals.

<i>Diictodon</i> Extinct genus of dicynodonts

Diictodon is an extinct genus of pylaecephalid dicynodont that lived during the Late Permian period, approximately 255 million years ago. Fossils have been found in the Cistecephalus Assemblage Zone of the Madumabisa Mudstone of the Luangwa Basin in Zambia and the Tropidostoma Assemblage Zone of the Teekloof Formation, Tapinocephalus Assemblage Zone of the Abrahamskraal Formation, Dicynodon Assemblage Zone of the Balfour Formation, Cistecephalus Assemblage Zone of the Middleton or Balfour Formation of South Africa and the Guodikeng Formation of China. Roughly half of all Permian vertebrate specimens found in South Africa are those of Diictodon. This small herbivorous animal was one of the most successful synapsids in the Permian period.

<i>Cistecephalus</i> Assemblage Zone

The Cistecephalus Assemblage Zone is a tetrapod assemblage zone or biozone found in the Adelaide Subgroup of the Beaufort Group, a majorly fossiliferous and geologically important geological group of the Karoo Supergroup in South Africa. This biozone has outcrops located in the Teekloof Formation north-west of Beaufort West in the Western Cape, in the upper Middleton and lower Balfour Formations respectively from Colesberg of the Northern Cape to east of Graaff-Reinet in the Eastern Cape. The Cistecephalus Assemblage Zone is one of eight biozones found in the Beaufort Group, and is considered to be Late Permian in age.

<i>Endothiodon</i> Extinct genus of dicynodonts

Endothiodon is an extinct genus of medium to large dicynodont from the Late Permian. Like other dicynodonts, Endothiodon was an herbivore, but it typically lacked the two tusks that characterized most other dicynodonts and instead had long rows of teeth inset in the jaws that replaced in waves. The anterior portion of the upper and lower jaw are curved upward, creating a distinct beak that is thought to have allowed them to be specialized grazers.

<i>Wadiasaurus</i> Extinct genus of dicynodonts

Wadiasaurus is an extinct genus of dicynodont from the family Kannemeyeria, that lived in herds from the early to Middle Triassic. Substantial fossorial evidence of W. indicus was recovered from Yerrapalli Formation of the Pranhita-Godavari valley, India, and it is so far the only Kannemeyeriid known for certain from India. The Kannemeyeriiformes underwent a significant diversification during the middle Triassic, with roughly 40 known species distributed worldwide. All Kannemeyeriiformes were medium to large bodied, graviportal herbivores with relatively erect posture and gait. Wadiasaurus indicus is currently the only known species of Wadiasaurus.

<i>Theriognathus</i> Extinct genus of therapsids from late Permian South Africa and Tanzania

Theriognathus is an extinct genus of therocephalian therapsid belonging to the family Whaitsiidae, known from fossils from South Africa, Zambia, and Tanzania. Theriognathus has been dated as existing during the Late Permian. Although Theriognathus means mammal jaw, the lower jaw is actually made up of several bones as seen in modern reptiles, in contrast to mammals. Theriognathus displayed many different reptilian and mammalian characteristics. For example, Theriognathus had canine teeth like mammals, and a secondary palate, multiple bones in the mandible, and a typical reptilian jaw joint, all characteristics of reptiles. It is speculated that Theriognathus was either carnivorous or omnivorous based on its teeth, and was suited to hunting small prey in undergrowth. This synapsid adopted a sleek profile of a mammalian predator, with a narrow snout and around 1 meter long. Theriognathus is represented by 56 specimens in the fossil record.

<i>Myosaurus</i> Extinct genus of dicynodont from the lower Triassic

Myosaurus is a genus of dicynodont synapsids. Myosaurus was a small, herbivorous synapsid that existed around the early Triassic period. All of the fossils found of this species were found in Antarctica and South Africa. Compared to other fossils found from species that existed during this time, the Myosaurus is not common in the fossil record. This is due to a shortage of discovered fossils that possess characteristics unique to the Myosaurus. Notably, under 130 fossil fragments have been found that have been classified as Myosauridae, and almost all have been skulls. These skulls can be classified as Myosaurus because this species, unlike other dicynodonts, do not possess tusks or postfrontal teeth. The only species identified in the family Myosauridae is the Myosaurus gracilis, or M. gracilis. It should be recognized that the Myosaurus is almost always referred to as the M. gracilis in scientific research.

<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>Dicynodontoides</i> Extinct genus of dicynodonts

Dicynodontoides is a genus of small to medium-bodied, herbivorous, emydopoid dicynodonts from the Late Permian. The name Dicynodontoides references its “dicynodont-like” appearance due to the caniniform tusks featured by most members of this infraorder. Kingoria, a junior synonym, has been used more widely in the literature than the more obscure Dicynodontoides, which is similar-sounding to another distantly related genus of dicynodont, Dicynodon. Two species are recognized: D. recurvidens from South Africa, and D. nowacki from Tanzania.

<i>Eosimops</i> Extinct genus of dicynodonts

Eosimops is an extinct genus of pylaecephalid dicynodonts. They were small synapsids superficially resembling modern mammals. Eosimops is known from several skull specimens, as well as one complete skeleton. Eosimops lived during the Middle Permian of South Africa.

<i>Kawingasaurus</i> Extinct genus of dicynodonts

Kawingasaurus is an extinct genus of dicynodont therapsid from the Late Permian Usili Formation of Tanzania. It is a member of the family Cistecephalidae, and like other cistecephalids it is thought to have been fossorial. It is a member of the family Cistecephalidae. Cistephalidae includes genera Cisteceohalus, Cistecephaloides and Kawingasaurus. Greek for Saurus meaning “lizard” appears as a suffix denoting a reptilian origin. Living between 254.17 and 259.9 million years ago in the late Permian and believed to have the first and last recorded appearance in this time period. It lived in deep burrows as a suggested by most burrowing dicynodonts from evaluation of cranial sutures, vestibule inflation and enlarged stapes foot plates which are thought to be functionally correlated with bone-conduction hearing; all observed in fossorial vertebrates which use seismic signals as communication.

Zambiasaurus is an extinct genus of dicynodonts that was discovered in the Middle Triassic (Anisian) Ntawere Formation of Zambia, southern Africa. It was a large dicynodont, reconstructed using several fossil fragments, in majority belonging to probably a juvenile Zambiasaurus submersus.

Sintocephalus is an extinct genus of dicynodont therapsid from the Late Permian of South Africa. Fossils are known from the Cistecephalus Assemblage Zone of the Beaufort Group. The type species of Sintocephalus, S. alticeps, was first named in 1913 as a species of Dicynodon. The genus was erected in 1934, but in subsequent years its species were often regarded as members of other dicynodont genera.

<span class="mw-page-title-main">Emydopoidea</span> Extinct superfamily of dicynodonts

Emydopoidea is a group of Late Permian dicynodont therapsids. It includes the small-bodied Emydops, Myosaurus, and kingoriids, and the burrowing cistecephalids.

<span class="mw-page-title-main">Kistecephalia</span> Extinct clade of dicynodonts

Kistecephalia is a clade of dicynodont therapsids. The group was first named in 1894, and was reinstated as a clade in 2009. Kistecephalia is a stem-based taxon defined as all taxa more closely related to Cistecephalus microrhinus than Emydops arctatus. It includes the families Myosauridae, Kingoriidae, and Cistecephalidae and is part of the larger group Emydopoidea. Kistecephalians were small in comparison to other dicynodonts. One group of kistecephalians, the cistecephalids, are thought to have been burrowers. Below is a cladogram from Kammerer et al. (2011) showing the phylogenetic relationships of kistecephalians:

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

Anomocephaloidea is a clade of basal anomodont therapsids related to the dicynodonts known from what is now South Africa and Brazil during the Middle Permian. It includes only two species, Anomocephalus africanus from the Karoo Basin of South Africa and Tiarajudens eccentricus from the Paraná Basin of Brazil. Anomocephaloidea was named in 2011 with the discovery of Tiarajudens, although Anomocephalus itself has been known since 1999.

Sauroscaptor is a genus of cistecephalid dicynodont from the upper Permian of India, containing one species, S. tharavati. It is remarkable for the extreme placement of its pineal foramen, which bulges out of the posterior margin of its skull.

<i>Bulbasaurus</i> Extinct genus of dicynodonts

Bulbasaurus is an extinct genus of dicynodont that is known from the Lopingian epoch of the Late Permian period of what is now South Africa, containing the type and only species B. phylloxyron. It was formerly considered as belonging to Tropidostoma; however, due to numerous differences from Tropidostoma in terms of skull morphology and size, it has been reclassified the earliest known member of the family Geikiidae, and the only member of the group known from the Tropidostoma Assemblage Zone. Within the Geikiidae, it has been placed close to Aulacephalodon, although a more basal position is not implausible.

<i>Thliptosaurus</i> Extinct genus of dicynodonts

Thliptosaurus is an extinct genus of small kingoriid dicynodont from the latest Permian period of the Karoo Basin in KwaZulu-Natal, South Africa. It contains the type and only known species T. imperforatus. Thliptosaurus is from the upper Daptocephalus Assemblage Zone, making it one of the youngest Permian dicynodonts known, living just prior to the Permian mass extinction. It also represents one of the few small bodied dicynodonts to exist at this time, when most other dicynodonts had large body sizes and many small dicynodonts had gone extinct. The unexpected discovery of Thliptosaurus in a region of the Karoo outside of the historically sampled localities suggests that it may have been part of an endemic local fauna not found in these historic sites. Such under-sampled localities may contain 'hidden diversities' of Permian faunas that are unknown from traditional samples. Thliptosaurus is also unusual for dicynodonts as it lacks a pineal foramen, suggesting that it played a much less important role in thermoregulation than it did for other dicynodonts.

Kembawacela is an extinct genus of cistecephalid dicynodont from the Late Permian of East Africa. The genus contains two known species, the type species Kembawacela kitchingi from the Madumabisa Mudstone Formation of Zambia described in 2019, and a second species, K. yajuwayeyi, from the Chiweta Beds of Malawi described in 2022. Like other cistecephalids, Kembawacela was specialised for a fossorial, burrowing lifestyle similar to modern day moles. It is unique amongst cistecephalids for the presence of a pair of tusks in the upper jaw, characteristic of many other dicynodonts but lost in other cistecephalids. It is likely that Kembawacela was a locally endemic species of cistecephalid in the Luangwa Basin of Zambia.

References

  1. 1 2 Kammerer, C.F.; Angielczyk, K.D. (2009). "A proposed higher taxonomy of anomodont therapsids" (PDF). Zootaxa. 2018: 1–24.
  2. Ray, S.; Chinsamy, A. (2003). "Functional aspects of the postcranial anatomy of the Permian dicynodont Diictodon and their ecological implications". Palaeontology. 46 (1): 151–183. Bibcode:2003Palgy..46..151R. doi: 10.1111/1475-4983.00292 .
  3. 1 2 3 4 Kammerer, C. F.; Bandyopadhyay, Saswati; Ray, Sanghamitra (2016). "A new taxon of cisticephalid dicynodont from the upper Permian Kundaram Formation of India". Papers in Palaeontology. 2 (4): 569–584. Bibcode:2016PPal....2..569K. doi:10.1002/spp2.1055. S2CID   88833541.
  4. 1 2 Nasterlack, Tobias; Canoville, Aurore; Chinsamy, Anusuya (2012). "New insights into the biology of the Permian genus Cistecephalus (Therapsida, Dicynodontia)". Journal of Vertebrate Paleontology. 32 (6): 1396–1410. Bibcode:2012JVPal..32.1396N. doi:10.1080/02724634.2012.697410. JSTOR   23361056. S2CID   86333197.