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| Nyana rooiwalensis Moopen, Botha, Benson, Chapelle, Barrett, Dollman & Choiniere, 2026 |
Abstract
Triassic sauropodomorph cranial material is known primarily from Argentina, Brazil and Europe and is sparsely distributed across the phylogenetic tree. In southern Africa, only two Late Triassic taxa preserve cranial elements, Mbiresaurus and Kholumolumo, both represented by limited material. Here we describe Nyana rooiwalensis, a new early-branching sauropodomorph from the Upper Triassic lower Elliot Formation of South Africa, represented by the first well-preserved, near-complete skull to be recovered from the unit. The holotype comprises the braincase, palate, the hyoid apparatus and scleral rings, as well as associated postcranial elements. Body mass estimates predict Nyana was approximately 400 kg yet osteohistological analyses show at most two lines of arrested growth and a crenulated periosteal surface, indicating an early ontogenetic stage. These observations support the early evolution of rapid growth in Sauropodomorpha, foreshadowing the evolution of sauropod gigantism. Phylogenetic analyses place Nyana as the sister taxon to either the North American Sarahsaurus or the South African Ngwevu and is recovered as either an early-branching massopodan or nested within Massospondylidae. The exceptional preservation, early ontogenetic stage and phylogenetic position of Nyana provide critical insights into cranial evolution, postural and locomotory behaviours, body mass and growth dynamics during the early diversification of Sauropodomorpha.
Keywords: Sauropodomorpha, lower Elliot Formation, Norian–Rhaetian, cranial anatomy, osteohistology
Systematic palaeontology
Dinosauria Owen, 1842
Saurischia Seeley, 1888
Sauropodomorpha von Huene, 1932
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| Photographs of the skull of Nyana rooiwalensis. (a) Dorsal, (b) left lateral and (c) ventral views. Scale bar = 5 cm. |
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| Reconstructed skull of Nyana rooiwalensis. (a) Right lateral and (b) left lateral views. Abbreviations: a, angular; ana, atlantal neural arch; aof, antorbital fenestra; ati, atlantal intercentrum; bo, basioccipital; cb, ceratobranchial; co, coronoid; d, dentary; fr, frontal; j, jugal; hy, hyoid; itf, infratemporal fenestra; j, jugal; la, lacrimal; mf, mandibular fenestra; mx, maxilla; obt, orbit; otc, otoccipital; pa, parietal; pat, proatlas; pl, palatine; po, postorbital; pra, prearticular; pt, pterygoid; q, quadrate; sa, surangular; sp, splenial; sq, squamosal. Scale bar = 25 mm. |
Nyana rooiwalensis gen. et sp. nov.
Etymology. From Xhosa and Sesotho, ‘nyana’ means son or reference to a child (Xhosa), and small or little (Sesotho), in reference to its early ontogenetic stage but comparably large body size. The specific name is in reference to Rooiwal, Eastern Cape Tribal Administrative Area 17, in which the fossil site is located.
Diagnosis. Nyana rooiwalensis differs from all other sauropodomorphs on the basis of a unique character combination and three autapomorphies (the latter indicated by ‘*’): at least 23 alveoli in the maxilla; the ascending ramus of the maxilla extends at a 40° angle from its long axis*; the postorbital is mediolaterally thickened with straight rami*; the supratemporal fossa is well-developed and expansive, encroaching on the posterior margin of the frontal; the quadrate ramus of the squamosal extends near vertically; a foramen is present on the posteromedial surface of the jugomaxillary ramus of the palatine*; the orbitosphenoid is ‘C’-shaped with an anteroposteriorly long ...
Atashni Moopen; Jennifer Botha; Roger Benson; Kimberley E. J. Chapelle; Paul M. Barrett; Kathleen Dollman and Jonah N. Choiniere. 2026. Nyana rooiwalensis: South Africa's Earliest near-complete Sauropodomorph Dinosaur Skull from the Late Triassic of the Eastern Cape Province. R. Soc. Open Sci. 13 (11): 261002. DOI: doi.org/10.1098/rsos.261002 [11 Nov 2026]
