New morphological information about Cretaceous sauropod dinosaurs from the Eromanga Basin, Queensland, Australia

Abstract

New observations on various sauropod postcranial elements from Queensland provide insights into the taxonomic composition of northern Australia's sauropod fauna and the structure of sauropod vertebrae. An incomplete sauropod humerus from a site near Blackall, Queensland, represents the southernmost occurrence of sauropod fossils in the Eromanga Basin, and indicates a possibly new taxon. The internal architecture of at least one of the vertebral centra of Austrosaurus mckillopi comprises bony disks parallel to the posterior articular face and bony lamellae perpendicular to the anterior articular face reinforcing the structure against axial forces. The lack of pneumaticity proximally in dorsal ribs indicates that A. mckillopi may not be a titanosauriform. Material (QM F6737) from the Winton Formation includes probable osteoderms, the first known from Australian sauropods, and some of the oldest known. Comparison of this specimen with named Winton Formation sauropods suggests that it represents a distinct taxon.