Abstract A partial rostrum of a new species of scaphognathine pterosaur, distinguished by a thin median crest along its dorsal margin and a deep embayment of the dental margin, is the first identifiable cranial fragment of a pterosaur from the Upper Jurassic Morrison Formation of western North America. By contrast with pterodactyloids, cranial crests are rare in “rhamphorhynchoids” and this is the first record of such a structure. The new material provides fresh insights into the taxonomic diversity of Late Jurassic North American pterosaurs. Based on the ratio of the skull and skeleton of Scpahognathus, the fragment represents an individual with an estimated wing span of 2.5 m. Consequently, this is one of the largest “rhamphorhynchoids” found so far. A mandible fragment from the same quarry has closely spaced alveoli, therefore cannot be referred to the rostrum. Its large size indicates another large “rhamphorhynchoid” in the Morrison Formation.