Bauria, Euchambersia, Promoschorhynchus and the Therocephalia

Promoschorhynchus platyrhinus (Brink 1954; Huttenlocker, Sidor and Smith 2011; Latest Permian, Earliest Triassic; SAM-PK-K10014) is a South African therocephalian.

Charassognathus gracilis (Botha et al. 2007; Late Permian; skull length 5cm) was originally considered the oldest and most basal cynodont based on the large size of the temporal fenestrae. Here it nests within the Therocephalia, basal to the Cynodontia.

Euchambersia mirabilis (Broom 1931; Benoit et al. 2017; Late Permian; skull length 10cm; NHMUK R5696) has an odd antorbital fenestra (maxillary fossa) that may have housed a venom gland. The continuity of the septomaxilla with the lacrimal/prefrontal is clear here. A relationship with Charassognathus (above), a taxon with a postcanine bluge, is recovered by the LRT. Note: the skull abvoe is deformed.

Bauria cynops (Broom 1909; Brink 1963; Early Triassic, 250mya) was a therocephalian theriodont synapsid with occluding post-canine teeth, the first instance in the lineage of pre-mammals. Note the imminent closure of the palate and the posterior shift of the internal nares along with the confluence of the orbit and lateral temporal fenestra.

Benoit J, NortonLA, Manger PR and Rubidge BS 2017. Reappraisal of the envenoming capacity of Euchambersia mirabilis (Therapsida, Therocephalia) using μCT-scanning techniques. PLoS ONE 12(2): e0172047. doi:10.1371/journal.pone.0172047

Broom R 1931. Notices of some new Genera and species of Karroo Fossil Reptiles. Rec Albany Mus. 1931; 41: 161–166.

Brink AS 1954. On the Whaitsiidae, a family of therocephalian mammal-like reptiles. TransactionBrink, A.S. (1965). "A New Large Bauriamorph From the Cynognathus-Zone of South Africa".s of the Royal Society of South Africa 34:43–59.

Huttenlocker AK, Sidor CA and Smith AMH 2011. A new specimen of Promoschorhynchus (Therapsida: Therocephalia: Akidnognathidae) from the Lower Triassic of South Africa and its implications for theriodont survivorship across the Permo-Triassic boundary. Journal of Vertebrate Paleontology 31(2):405–421.

Kammerer CF 2016. A new taxon of cynodont from the Tropidostoma Assemblage Zone (upper Permian) of South Africa, and the early evolution of Cynodontia. Papers in Palaeontology 2(3): 387–397. https://doi.org/10.1002/spp2.1046

wiki/Promoschorhynchus
wiki/Charassognathus
wiki/Bauria
wiki/Euchambersia

Therapsida

Cutleria

Anomodontia

Hipposaurus

Stenocybus

Galechirus - Galepus

Patranomodon

Eodicynodon - Dicynodon

Suminia

Venjukovia • Otsheria

Tiarajudens