Laramide orogeny prior to their extinction." This turnover event saw the replacement of specialized and highly ornamented centrosaurine and lambeosaurines by more basal upland dinosaurs in the south, while northern biomes became dominated by "Triceratops" with a greatly reduced hadrosaur community. Laramide orogeny The Laramide orogeny was a period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the orogeny are in dispute. The Laramide orogeny occurred in a series of pulses, with quiescent
Hunter-Bowen orogeny Hunter-Bowen orogeny The Hunter-Bowen Orogeny was a significant arc accretion event in the Permian and Triassic periods affecting approximately 2,500 km of the Australian continental margin. The Hunter-Bowen Orogeny occurred in two main phases, a Permian accretion of previously formed passive-marginal Devonian and Carboniferous sediments in the Hunter region and mid-west region of what is now New South Wales, separated by rifting, back-arc volcanism and a later Permian to Triassic event resulting in arc accretion and metamorphism during a subduction event. The Hunter-Bowen Orogeny has resulted in the New England Fold Belt, a tectonic accretion of metamorphic terranes and mid-crustal