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.

New Australian sauropods shed light on Cretaceous dinosaur palaeobiogeography.

Australian dinosaurs have played a rare but controversial role in the debate surrounding the effect of Gondwanan break-up on Cretaceous dinosaur distribution. Major spatiotemporal gaps in the Gondwanan Cretaceous fossil record, coupled with taxon incompleteness, have hindered research on this effect, especially in Australia. Here we report on two new sauropod specimens from the early Late Cretaceous of Queensland, Australia, that have important implications for Cretaceous dinosaur palaeobiogeography.

New Australovenator hind limb elements pertaining to the holotype reveal the most complete Neovenatorid leg.

We report new skeletal elements pertaining to the same individual which represents the holotype of Australovenator wintonensis, from the 'Matilda Site' in the Winton Formation (Upper Cretaceous) of western Queensland. The discovery of these new elements means that the hind limb of Australovenator is now the most completely understood hind limb among Neovenatoridae. The new hind limb elements include: the left fibula; left metatarsal IV; left pedal phalanges I-2, II-1, III-4, IV-2, IV-3; and right pedal phalanges, II-2 and III-1.

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.