In the show the Pteranodon Family lived near to the Western Interior Sea. The creatures there lived during the time called Campanian. This time is home to many creatures like Pteranodons, Nyctosaurus, Ichthyornis, Deinosuchus, Cretoxyrhina, Archelon, Elasmosaurus, Enchodus, Hesperoris, and Xiphactinus. That is just over the sea, on land there are large dinosaurs such as Alamosaurus, Euoplocephalus, Lambeosaurus, Daspletosaurus, and Styracosaurus. There where smaller dinosaurs such as Troodon and Chirostenotes. But there are not just dinosaurs, there are mammals like Cimolestes, turtles like Adocus, anphibeans like Albanerpeton and birds like Enantiornthes and Avisaurs. Sorry to burst anyones bubble but Palaeobatrachus is a Eocene Epoch from the age of mammals. As for the small mammal Cimolestes it and Adocus and Albanerpeton survied into the Paleocene epoch. The point is there is more animals that lived near to the sea including other large Hedrosaurs called Kritosaurus. This vast ecosystem is different from the inland of North America.