"Nyctosaurus" was a mid-sized pterosaur that lived along the shores of the Niobrara Formation of the United States, which back then was within a large inland sea called the Western Interior Seaway. It has been suggested that it would have flown similar to modern-day soaring birds such as albatrosses, which consisted of flying very long distances and rarely flapping. The species "N. gracilis" and "N. nanus" have previously been considered as species of the closely related "Pteranodon", back then known as "P. gracilis" and "P. nanus", due to their similarities.