It all started with the Bone Wars, also known as the "Great Dinosaur Rush," of the late 1800s. Two rivals with huge egos went up against each other in an epic fossil hunt in the newly opened western half of the United States. In one corner was the bombastic Quaker Edward Drinker Cope of the Academy of Natural Sciences in Philadelphia. In the other corner was America's first appointed paleontologist Othniel Charles Marsh of the Yale Peabody Musuem in Connecticut.
Marsh was the first to find pterosaurs in North America, the flying reptiles that lived alongside the dinosaurs during the Mesozoic Era of geologic time. The very first discovery was the popular Pteranodon of the Niobrara Chalk of Nebraska. But Marsh also unknowingly found another pterosaur and mistook it initially for Pteranodon.
Marsh's fossil specimens weren't very complete, so the confusion was understandable. But later he reclassified his second discovery as Nyctosaurus, the pterosaur that later became recognized for its wild "antler".