Nyctosauridae

Nyctosauridae (meaning "night lizards" or "bat lizards") is a family of specialized soaring pterosaurs of the late Cretaceous Period of North America and, possibly, Europe. It was named in 1889 by Henry Alleyne Nicholson and Richard Lydekker.

Nyctosaurids are characterized by their lack of all but the wing finger. In most pterosaurs, the hand has four fingers, with the fourth elongated to support the wing, and the remaining three are usually small, clawed, and used in walking or climbing. The lack of functional fingers in nyctosaurids may suggest that they spent almost all of their time in the air, rarely walking on the ground. Nyctosaurids also possessed a distinctively enlarged crest for muscle attachment on their upper arm bone, or humerus, the deltopectoral crest.