A new kannemeyeriiform dicynodont (Ufudocyclops mukanelai, gen. et sp. nov.) from Subzone C of the Cynognathus Assemblage Zone, Triassic of South Africa, with implications for biostratigraphic correlation with other African Triassic faunas

ABSTRACT

A new taxon of kannemeyeriiform dicynodont, Ufudocyclops mukanelai, is described based on a well-preserved skull from Subzone C of the Cynognathus Assemblage Zone, which are the youngest strata (probably Middle Triassic) of the Beaufort Group (uppermost Burgersdorp Formation) in South Africa. Ufudocyclops mukanelai is diagnosed by its autapomorphic intertemporal morphology: the intertemporal bar in this taxon is ‘X’-shaped—broad anteriorly and posteriorly but distinctly ‘pinched’ at mid-length and bears a deep, triangular depression immediately behind the enormous pineal foramen. The new kannemeyeriiform can also be diagnosed by the presence of a laterally expanded jugal plate beneath the orbit, and highly discrete, ovoid nasal bosses separated by a broad, unornamented median portion of the premaxilla and the nasals. Two partial dicynodont skulls from this subzone, previously identified as specimens of the otherwise Tanzanian taxon Angonisaurus, are also referable to U. mukanelai. Removal of these specimens from the hypodigm of Angonisaurus eliminates a crucial point of correlation between Cynognathus Subzone C and the Manda Beds of Tanzania and suggests that Subzone C preserves a distinct, endemic fauna, not just a southern extension of the better-known Middle–Late Triassic tetrapod faunas from Tanzania and Zambia. Inclusion of Ufudocyclops in a phylogenetic analysis of anomodonts recovers it as an early stahleckeriid, the first record of this clade from the Cynognathus Assemblage Zone.

ACKNOWLEDGMENTS

We thank D. Osborne, owner of the farm Thala on which the holotype BP/1/8208 was found. We thank all members of the 2014 and 2017 Cynognathus C field teams: E. Bordy, D. Cashmore, M. Day, K. Dollman, E. Dunne, M. Ezcurra, P. Godoy, A. Jones, B. McPhee, J. Neenan, and R. Sookias. C.F.K. thanks the many curators and collections managers who have provided access to comparative materials, especially S. Jirah (ESI), I. Werneburg (GPIT), P. Barrett (NHMUK), V. Golubev (PIN), the late J. Powell (PVL), and C. Schultz (UFRGS). We thank C. Mdekazi for consultation on the genus name of the new dicynodont; K. Angielczyk, J. Fröbisch, B. Peecook, and T. Sulej for their helpful reviews; and A. Huttenlocker for his work as editor. Funding for field work was provided by a Marie Curie Career Integration Grant (630123 to R.J.B.), the NRF African Origins Platform (98800 to J.N.C.), and by Palaeontological Scientific Trust (J.N.C.).

ORCID

Christian F. Kammerer http://orcid.org/0000-0002-0596-623X

Richard J. Butler http://orcid.org/0000-0003-2136-7541