User:Draco ignoramus sophomoricus/sandbox campanian alt

During the Campanian age, a radiation among dinosaur species occurred. In North America, for example, the number of known dinosaur genera rises from 4 at the base of the Campanian to 48 in the upper part. This development is sometimes referred to as the "Campanian Explosion". However, it is not yet clear if the event is artificial, i.e. the low number of genera in the lower Campanian can be caused by a lower preservation chance for fossils in deposits of that age. The generally warm climates and large continental area covered in shallow sea during the Campanian probably favoured the dinosaurs. In the following Maastrichtian stage, the number of North American dinosaur genera found is 30% less than in the upper Campanian. Animals that lived in the Campanian include:

Theropoda
David J. Varrichio observes that during the late Campanian Alberta and Montana had very similar theropods despite significant differences in the types of herbivorous dinosaur faunas.