Cistecephalidae is an extinct family of dicynodonttherapsids 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]
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]
^ abcdKammerer, 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. S2CID88833541.
