Plateosauridae

Abstract: . The purpose of this application, under Article 75.5 of the Code, is to conserve the usage of the name Plateosaurus Meyer, 1837 (Upper Triassic, Germany), known from numerous articulated skeletons, several with complete skulls, from the Norian Plateosaurus bonebeds of Western Europe and Greenland. This was the first non-English, non-avian dinosaur and the second sauropodomorph and Triassic dinosaur to be named. It is proposed to replace the fragmentary and non-diagnostic bones that constitute the type material of Plateosaurus engelhardti Meyer, 1837, the type species of Plateosaurus Meyer, 1837, with a diagnostic neotype, an almost complete skull and skeleton (SMNS 13200). This specimen has formed the basis for the concept of P. engelhardti (the best represented basal sauropodomorph) and ultimately of Plateosaurus Meyer, 1837. Plateosaurus is the basis for plateosauridae Marsh, 1895 and Plateosauria Tornier, 1913.

Abstract: Triassic dinosaurs of Brazil are found in Santa Maria and Caturrita formations, Rio Grande do Sul state, Brazil. There are three species known from the Santa Maria Formation (Staurikosaurus pricei, Saturnalia tupiniquim and Pampadromaeus barberenai), and two from Caturrita Formation (Guaibasaurus candelariensis and Unaysaurus tolentinoi). These dinosaur materials are, for the most part, well preserved and allow for descriptions of musculature and biomechanical studies. The lateral rotation of the Saturnalia femur is corroborated through calculations of muscle moment arms. The enhanced supracetabular crest of Saturnalia, Guaibasaurus, Staurikosaurus, Herrerasaurus ischigualastensis, Efraasia minor and Chormogisaurus novasi suggests that basal dinosaurs may have maintained an inclination of the trunk at least 20o on the horizontal axis. The pectoral girdle articulation of basal sauropodomorphs (Saturnalia and Unaysaurus) was established using a new method, the Clavicular Ring, and the scapular blade remains near 60o on the horizontal axis. This is a plesiomorphic condition among sauropodomorphs and is also seen in the articulated plateosauridae Seitaad ruessi. The Brazilian basal dinosaurs were lightweight with a body mass estimated around 18.5 kg for Staurikosaurus, 6.5 kg for Saturnalia, and 17 kg for Guaibasaurus. Pampadromaeus probably weighed 2.5 kg, but measures of its femur are necessary to confirm this hypothesis. The Triassic dinosaurs from Brazil were diversified but shared some functional aspects that were important in an evolutionary context.

Abstract: We present a systematic revision of the ‘prosauropod’ dinosaur Unaysaurus tolentinoi. Past phylogenetic treatments of this taxon have presented it as a key constituent of the low-diversity Plateosa...