Cistecephalidae

Summary

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]

Cistecephalidae
Temporal range: Late Permian
Reconstruction of Cistecephalus microrhinus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Synapsida
Clade: Therapsida
Suborder: Anomodontia
Clade: Dicynodontia
Clade: Kistecephalia
Family: Cistecephalidae
Broom, 1913
Genera

Description edit

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 edit

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]

References edit

  1. ^ a b 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. ^ a b c d 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. ^ a b 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.