Solving a dinosaurian puzzle: the identity of Aliwalia rex Galton

Abstract

Eucnemesaurus fortis Van Hoepen 1920 from the Late Triassic of South Africa is demonstrated to be the senior synonym of the puzzling dinosaur taxon Aliwalia rex Galton 1985. A new specimen of this poorly-known taxon is described. Eucnemesaurus is clearly a sauropodomorph and increases the diversity of sauropodomorph taxa in the South African Late Triassic to six. It shares a number of femoral synapomorphies with Riojasaurus from the Late Triassic of Argentina and Riojasauridae tax. nov. is erected to accommodate them. These conclusions are supported by a comprehensive cladistic analysis of 46 sauropodomorph and other basal dinosauriform taxa using 353 osteological characters. This analysis also supports the paraphyletic nature of the traditional ‘prosauropod’ assemblage.

Keywords:

• Aliwalia
• Eucnemesaurus
• Late Triassic
• Sauropodomorpha
• South Africa
• Riojasauridae

Acknowledgements

Emese Bordy, John Hancox and Paul Dirks found the new Eucnemesaurus specimen while Pepson Mukanela and Doctor Mbense prepared some of the bones. I thank Naude Bremmer and Cobus Visser for allowing us to collect on Spioenkop and for their hospitality during our stay. Deigo Pol and Peter Galton are thanked for their review of the manuscript and their useful comments. I thank Francis Thackeray for access to specimens in the Transvaal Museum. Travel to China for the coding of Chinese taxa used in the phylogenetic analysis was supported by P.A.S.T.