New Forearm Elements Discovered of Holotype Specimen Australovenator wintonensis from Winton, Queensland, Australia

New skeletal elements are reported of the holotype specimen Australovenator wintonensis, from the type locality, near Winton, central western Queensland. New elements include left and right humeri, right radius, right radiale, right distal carpal 1, near complete right metacarpal I, left manual phalanx II-1, left manual phalanx II-2, near complete left manual phalanx II-3 and a left manual phalanx III-3. These new elements combined with those previously described are compared against other neovenatorids

Three-Dimensional Musculoskeletal Modeling of the Sauropodomorph Hind Limb: The Effect of Postural Change on Muscle Leverage

The biomechanical constraints for life at massive size can be directly observed in the evolutionary history of sauropodomorph dinosaurs. Members of this lineage underwent a number of major postural transitions as they increased in size from relatively small bipedal dinosaurs to massive titanosaurs that include the largest terrestrial animals of all time. To better understand the impact of gigantic size on the biomechanics of sauropods, we used three-dimensional musculoskeletal modeling to investigate how hind limb musculature was affected, first by the development of a quadrupedal stance from a bipedal one, and later in the transition from a narrow-gauge to a wide-gauge stance. Muscle moment arms were measured in four sauropodomorph taxa: the bipedal basal sauropodomorph Plateosaurus engelhardti, the narrow-gauge diplodocid Diplodocus carnegii, the titanosauriform Giraffatitan brancai, and the wide-gauge titanosaur Diamantinasaurus matildae. In Plateosaurus, low moment arm leverage in the hip extensors and knee flexors and extensors was observed suggesting high-velocity movement for fast locomotion. A reduction in hip extensor leverage in Diamantinasaurus was found which suggests a reduced role for the hind limb in forward propulsion in titanosaurs. An increase in overall hip adductor leverage and leverage of adductors 1 and 2 in Diamantinasaurus, compared with other taxa studied, might relate to the development of a wide-gauge stance. High knee flexor–extensor leverage in Giraffatitan but not Diamantinasaurus partially refutes the idea that broader femoral condyles in titanosauriforms increased knee torque production capabilities. Sauropodomorph postural changes clearly had an impact on the function and leverage of hind limb muscles

New Forearm Elements Discovered of Holotype Specimen Australovenator wintonensis from Winton, Queensland, Australia

New skeletal elements are reported of the holotype specimen Australovenator wintonensis, from the type locality, near Winton, central western Queensland. New elements include left and right humeri, right radius, right radiale, right distal carpal 1, near complete right metacarpal I, left manual phalanx II-1, left manual phalanx II-2, near complete left manual phalanx II-3 and a left manual phalanx III-3. These new elements combined with those previously described are compared against other neovenatorids

Revision of the sauropod dinosaur Diamantinasaurus matildae Hocknull et al. 2009 from the mid-Cretaceous of Australia : Implications for Gondwanan titanosauriform dispersal

The osteology of Diamantinasaurus matildae, the most complete Cretaceous sauropod described from Australia to date, is comprehensively reassessed. The preparation of additional material from the type locality, pertaining to the same individual as the holotype, sheds light on the morphology of the axial skeleton and provides additional information on the appendicular skeleton. The new material comprises two dorsal vertebrae, an incomplete sacrum (including four partial coalesced vertebrae), the right coracoid, the right radius, an additional manual phalanx, and a previously missing portion of the right fibula. In this study we identify thirteen autapomorphic characters of Diamantinasaurus, and an additional five characters that are locally autapomorphic within Titanosauriformes. This work provided an opportunity to revisit the phylogenetic placement of Diamantinasaurus. In two independent data matrices, Diamantinasaurus was recovered within Lithostrotia. One analysis resolved Diamantinasaurus as the sister taxon to the approximately coeval Tapuiasaurus from Brazil, whereas the second analysis recovered Diamantinasaurus as the sister taxon to Opisthocoelicaudia from the latest Cretaceous of Mongolia. The characters supporting the recovered relationships are analysed, and the palaeobiogeographical implications of the lithostrotian status of Diamantinasaurus are explored. A brief review of the body fossil record of Australian Cretaceous terrestrial vertebrates suggests close ties to South America in particular, and to Gondwana more generally

Right Radiale.

<p>Right Radiale in proximal (A & B), distal (C & D), dorsal (E & F), ventral (G & H). <i>Abbreviations:</i> cf, concave facet; cb, convex bulge.</p

Right Distal Carpal 1.

<p>Right Distal Carpal 1 in dorsal (A, B & C), proximal (D, E & F), disto-lateral (G, H & I), ventral (J, K & L), disto-medial (M & N) views. Computer generated renders with modified clay surfaces to represent missing elements are displayed in (C, F, I & L) views. <i>Abbreviations:</i> c, convave region; rp, rugose and pitted areas; rm, repaired margin; tm, thin matrix covering rugose areas.</p

Articulated right manus elements.

<p>Computer generated specimen renders with modified clay surfaces to represent missing elements. Ventral view (A), dorsal view (B). <i>Abbreviations:</i> Dc1, distal carpal 1; McI, metacarpal I; McI-1, manual phalanx I-1; McI-2, manual phalanx I-2; McII, metacarpal II; McII-1, manual phalanx II-1; McII-2, manual phalanx II-2; McII-3, manual phalanx II-3; McIII-1, manual phalanx III-1; McIII-3, manual phalanx III-3; r, radiale.</p

Locality Map and Stratigraphy.

<p>Location of Eromanga Basin and mid Cretaceous stratigraphy of the northern part of the Eromanga Basin. <i>Australovenator wintonensis</i> locality indicated *.</p

Left manual phalanx III-3.

<p>Left manual phalanx III-3 in medial (A), lateral (B), dorsal (C), ventral (D), proximal (E) and distal (F) views.</p

Left Metacarpal I.

<p>Left Metacarpal I in dorsal (A), medial (B), ventral (C), lateral (D), proximal (E), distal (F).</p