Anomocephaloidea

Anomocephaloidea
Temporal range: Middle Permian
Skulls of Anomocephalus (left) and Tiarajudens (right)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Synapsida
Clade: Therapsida
Suborder: †Anomodontia
Clade: †Anomocephaloidea
Cisneros et al., 2011
Genera

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 (the clade's namesake) 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.[1][2]

Anomocephaloids are characterised by batteries of tightly occluding molariform teeth at the back of the jaws, the first example of such teeth in the therapsid fossil record. Uniquely to anomocephaloids, though, the upper molariforms are in fact expanded palatal teeth from the roof of the mouth that occlude against the marginal dentition of the lower jaw. Such occlusion between palatal and marginal teeth is not known in any other synapsids. The precise occlusion, heavy wear, and rapid tooth replacement of anomocephaloid teeth all suggests that they fed upon tough, high-fibre vegetation. The adaptations of anomocephaloids to herbivory were novel both within anomodonts, but also for therapsids and mammal evolution as a whole.[3][4]

  1. ^ Modesto, S.; Rubidge, B.; Welman, J. (1999). "The most basal anomodont therapsid and the primacy of Gondwana in the evolution of the anomodonts". Proceedings of the Royal Society B: Biological Sciences. 266 (1417): 331–337. doi:10.1098/rspb.1999.0642. PMC 1689688.
  2. ^ Cisneros, J. C.; Abdala, F.; Rubidge, B. S.; Dentzien-Dias, P. C.; Bueno, A. d. O. (2011). "Dental Occlusion in a 260-Million-Year-Old Therapsid with Saber Canines from the Permian of Brazil". Science. 331 (6024): 1603–1605. doi:10.1126/science.1200305. PMID 21436452.
  3. ^ Cisneros, J. C.; Abdala, F.; Jashashvili, T.; De Oliveira Bueno, A.; Dentzien-Dias, P. (2015). "Tiarajudens eccentricus and Anomocephalus africanus, two bizarre anomodonts (Synapsida, Therapsida) with dental occlusion from the Permian of Gondwana". Royal Society Open Science. 2 (7): 150090. doi:10.1098/rsos.150090. PMC 4632579. PMID 26587266.
  4. ^ Fröbisch, J. (2011). "On Dental Occlusion and Saber Teeth". Perspective. Science. 331 (6024): 1525–1528. doi:10.1126/science.1204206. PMID 21436427.