Volume 41 December 2005
Permanent URI for this collectionhttps://wiredspace.wits.ac.za/handle/10539/13291
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Item A new theropod dinosaur from the Early Jurassic of South Africa and its implications for the early evolution of theropods(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 2005) Yates, Adam M.A new theropod, Dracovenator regenti, from the upper Elliot Formation is described, based upon a fragmentary skull. It can be diagnosed on the basis of a bilobed fossa on the lateral surface of the premaxilla that is connected to the alveolar margin by a narrow channel, the presence of a deep, oblique, lateral notch on the articular and hypertrophied dorsal processes on the articular. Other aspects of its morphology display a mosaic of coelophysoid and advanced theropod characteristics. A cladistic analysis of basal Theropoda, including the new taxon finds that the new taxon is closely related to Dilophosaurus wetherilli and Zupaysaurus rougieri although the clade formed by these three taxa is not robustly supported. It also finds that Coelophysoidea sensu lato is paraphyletic with respect to Ceratosauria + Tetanurae but that this topology is not a significantly better explanation of the data than an inclusive, monophyletic Coelophysoidea.Item Preliminary report of a large theropod dinosaur trackway in Clarens Formation sandstone (Early Jurassic) in the Paul Roux district, northeastern Free State, South Africa(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 2005) Raath, Michael A.; Yates, Adam M.An isolated fallen block of Clarens Formation sandstone near the small northeastern Free State town of Paul Roux preserves part of the trackway of a bipedal dinosaur. Although well known as a local curiosity, this trackway has not previously been formally reported or described. It consists of five successive paces of what is interpreted as a medium-sized to large theropod dinosaur, and represents the largest known theropod trackway in the ‘Stormberg’ sequence in South Africa. The tracks are assigned to the ichnotaxon Grallator sp., and show similarities to North American tracks of comparable age originally described as Dilophosauripus. Until now no body fossils of a likely candidate trackmaker were known, but elsewhere in this volume a possible candidate is described by the second author.Item New information on the palate and lower jaw of Massospondylus (Dinosauria: Sauropodomorpha)(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 2005) Barrett, Paul M.; Yates, Adam M.Additional anatomical details of the palate and lower jaw of the prosauropod dinosaur Massospondylus Owen are documented on the basis of a previously undescribed skull from the upper Elliot Formation. The palate is generally similar to that of other early sauropodomorphs, but can be shown to differ from those of Plateosaurus, Lufengosaurus and Thecodontosaurus in several respects. For example, Massospondylus lacks the well-developed palatine boss seen in Plateosaurus and the pneumatic recess that is present on the ectopterygoid of Thecodontosaurus. In addition, Massospondylus possesses an expanded medioventral premaxillary process that is much larger than that of any other basal sauropodomorph.