Quilmesaurus curriei Coria, 2001 (Dinosauria, Therapoda): Su validez taxonómica y relaciones filogenéticas

Abstract

A comparative analysis of the Cretaceous theropod Quilmesaurus curriei from the Río Negro province, Patagonia, Argentina was performed in order to elucidate its phylogenetic relationships. Quilmesaurus was considered as basal Tetanurae by Coria (2001), however, Kellner & Campos (2002) suggested that this theropod could be a possible Abelisauria. In our analysis, we observed that the lack of fusion of the tibia with the astragalus- calcaneum is not an exclusive character for Ceratosauria; moreover, the mediodistal crest of femur is commonly well developed in Abelisauroidea. The great development of the distally expanded cnemial crest and the asymmetrical distal end of the tibia are characteristics of Abelisauridae. Finally, other characters like a distally directed process at the end of the cnemial crest and the asymmetry in the origin of the expansion of the malleolii in distal tibia are regarded as synapomorphies of Carnotaurinae. Therefore, Quilmesaurus curriei is considered to belong to Abelisauridae, and it is possibly a member of Carnotaurinae. On the basis of the available evidence, it is not possible to identify autapomorphic characters that allow validating Quilmesaurus curriei, and for this reason we consider it as a nomen vanum.