Friday, May 31, 2019

[Paleontology • 2019] Ufudocyclops mukanelai • A New Kannemeyeriiform Dicynodont from Subzone C of the Cynognathus Assemblage Zone, Triassic of South Africa, with Implications for Biostratigraphic Correlation with other African Triassic Faunas


Ufudocyclops mukanelai
Kammerer, Viglietti, Hancox, Butler & Choiniere, 2019

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.

FIGURE 4. Ufudocyclops mukanelai, gen. et sp. nov., BP/1/8208, holotype, photograph and interpretive drawing in right lateral view. Gray indicates matrix; dotted lines indicate missing bone.

 Abbreviations: af, fossa for M. adductor mandibulae externus lateralis; cp, caniniform process of maxilla; fo, fenestra ovalis; fr, frontal; j, jugal; la, lacrimal; mx, maxilla; na, nasal; pa, parietal; pmx, premaxilla; po, postorbital; pr?, prootic; prf, prefrontal; pt, pterygoid; q, quadrate; smx, septomaxilla; sq, squamosal. Scale bar equals 5 cm.


FIGURE 10. Ufudocyclops and Angonisaurus compared.
A, B, holotype of Ufudocyclops mukanelai (BP/1/8208) in A, dorsal and B, right lateral views.
C, D, holotype of Angonisaurus cruickshanki (NHMUK PV R9732) in C, dorsal and D, left lateral views; D is mirrored for comparative purposes. Scale bars equal 5 cm.


SYSTEMATIC PALEONTOLOGY

 SYNAPSIDA Osborn, 1903 
THERAPSIDA Broom, 1905 
ANOMODONTIA Owen, 1860 

DICYNODONTIA Owen, 1860 
KANNEMEYERIIFORMES Maisch, 2001 
STAHLECKERIIDAE Lehman, 1961 

UFUDOCYCLOPS MUKANELAI, gen. et sp. nov.

Etymology— From the Xhosa ufudo, meaning tortoise (in reference to the toothless, tortoise-like beak), and the Ancient Greek cyclops, a one-eyed mythological giant (in reference to the enormous opening for the pineal eye on the dorsal midline of the skull). Species named in honor of Mr. Pepson Mukanela, in recognition of his many years working in the preparatory laboratory of the Evolutionary Studies Institute (and its predecessor, the Bernard Price Institute for Palaeontological Research) and in particular his skillful preparation of BP/1/8208.


Christian F. Kammerer, Pia A. Viglietti, P. John Hancox, Richard J. Butler and Jonah N. Choiniere. 2019. 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. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2019.1596921