Family Rhamphorhynchidae.
Jurassic. Rhamphorhynchus Meyer, Scaphognathus Wagner, Dimorphodon Meyer, Dorygnathus Orpel, Campylognathus Plieninger, Europe.
B. Suborder Pterodactyloidea
Wing metacarpal, longer or but little shorter than forearm. Tail very short. No cervical ribs. Fifth toe more or less reduced.
Family Pterodactylidae. Nares and antorbital vacuity more or less coalescent. Teeth in anterior part of jaws. Anterior dorsal vertebrae not fused. All metacarpals articulating with carpus. Prepubes not band-like. Smaller.
Upper Jurassic. Pterodactylus Cuvier (Ornithocephalus Sommering, Diopecephalus Seeley, Cycnorhamphus Seeley, Pterodracon Lydekker), Europe.
Family Ornithocheiridae. Skull more elongate. A supraoccipital crest. Scapula with enlarged distal end articulating with notarium. Jaws with teeth in front. Skeleton imperfectly known.
Wealden. Ornithocheirus Seeley, Ornithodesmus Seeley, England.
Family Pteranodontidae. Skull much elongated, toothless. A long supraoccipital crest. Orbits small. No antorbital opening. No fibula; fifth toe without phalanges. First three metacarpals splint-like. Upper end of scapula articulating with notarium. Prepubes band-like. From twelve to twenty-five feet in expanse of wings.
Upper Cretaceous. Pteranodon Marsh, North America. Ornithostoma (? Pteranodon) Seeley, England.
Family Nyctosauridae. Like the Pteranodontidae, but no occipital crest, and the upper end of scapula flat, not articulating with notarium. Eight-foot wing expanse.
Cretaceous. Nyctosaurus (Nyctodactylus) Marsh, Kansas.
Genera Incertae Sedis. Doratorhynchus Seeley, Paleornis Mantell, England.
Lower Cretaceous. Dermodactylus Marsh, Wyoming.
