Polar dinosaur bone histology

Abstract
We report on the bone microstructure of a hypsilophodont and an ornithomimosaur from the Early Cretaceous, Otway Group of Dinosaur Cove in south-eastern Australia, which at the time lay well within the Antarctic Circle. Although subjected to the same environmental conditions, the dinosaurs exhibit different bone histology. The hypsilophodontid shows a continuous rate of bone deposition, while the ornithomimosaur has a cyclical pattern of bone formation. We interpret these varying patterns of bone microstructure as a reflection of different growth strategies of these dinosaurs.