The fossil record shows a staggering variety of hadrosaur forms in Laramidia. Other differences in genera appear between the island land masses. Sauropods roamed Laramidia during the Cretaceous after apparently dying out in Appalachia. Nodosaurs, though, appear to have been more plentiful in Appalachia. Nodosaurs were large, herbivorous armored dinosaurs which lacked the giant club tail of their western relatives. They were scarce in Laramidia by the late Cretaceous, existing only in specialized forms like Edmontonia and Panoplosaurus while nodosaurs were thriving in Appalachia. References Geology of North America Historical continents Geology of Alberta Geology of Saskatchewan Regional geology of the United States Western United States