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An incomplete right metacarpal IV of a pterosaur from the late Albian Paw Paw Formation of Texas, USA, is the second pterosaur from that formation and an important addition to the sparse pterosaur record of the Albian of North America. Although the proximal and distal ends are missing, what remains of the shaft is straight and slender with little taper, little anteroposterior compression, and a distinct distal neck, and indicates the individual was of modest size despite being fully mature, and on that basis the specimen is referred to the Tapejarinae and is the first record of that taxon in North America. The specimen exhibits numerous bite marks of various types that are interpreted as resulting from intense scavenging by at least two different shark species and perhaps a bony fish. [ABSTRACT FROM AUTHOR]

A new juvenile specimen of Pteranodon from the Smoky Hill Chalk Member of the Niobrara Formation of western Kansas had an estimated wingspan in life of 1.76 m, ~45% smaller than the smallest previously known specimens, but does not differ in morphology from larger specimens. Its presence indicates that juveniles were capable of flying long distances, so it falsifies the interpretation of Pteranodon as growing rapidly to adult size under parental care before flying. Instead juveniles were precocial, growing more slowly to adult size while flying and feeding independently for several years before going to sea. Because juveniles are otherwise unknown in the Smoky Hill Chalk Member, they must have occupied different environments and ecological niches than adults; thus Pteranodon exhibited ontogenetic niches. Evidence is presented that most other pterosaurs (e.g., Rhamphorhynchus, Pterodactylus, Anhanguera) also exhibited various ontogenetic niches, which, along with their large body size, suggests that pterosaur taxonomic diversity was rather low, like that of crocodilians. [ABSTRACT FROM AUTHOR]

The Zittel wing of Rhamphorhynchus muensteri is reinterpreted as preserving negative impressions of closely spaced broad flat actinofibrils that were replaced by calcite but were prepared away by the specimen's finder. The Marsh specimen preserves positive impressions of the dorsal and ventral surfaces of the wing, which show that the skin was smooth with fine wrinkles and that actinofibrils were not on the wing surface. Based on comparisons of those specimens, the dactylopatagium consisted of dorsal and ventral skins of epidermis and dermis surrounding a common hypodermis core, and keratinous actinofibrils developed in place within the dorsal epidermis adjacent to a layer of linear collagen fibers in the dorsal dermis. The actinofibrils and linear collagen fibers together formed the main functional structure of the dactylopatagium. That structure made the dactylopatagium somewhat stiff and essentially inextensible so that it folded up along discrete fold lines that probably were genetically determined. A pneumatic retrophalangeal wedge behind the antebrachium through at least wing phalanx 3 streamlined the transition between the thick wing spar and thin patagium. [ABSTRACT FROM AUTHOR]

It was claimed that pterosaurs had external mandibular fenestrae, antorbital fossae and muscle scars homologous with the femoral fourth trochanter of archosauriforms, and that those characters suggested that the Pterosauria were within the clade Erythrosuchus + Archosauria. Pertinent parts of available specimens are described to confirm that one pterosaur had external mandibular fenestrae and one had antorbital fossae. However, arguments are presented that possession of external mandibular fenestrae does not support inclusion of the Pterosauria within the clade Erythrosuchus + Archosauria and that the antorbital fossae in the one pterosaur are not homologous with those of the clade Erythrosuchus + Archosauria. Arguments are also presented that the possession of a m. caudofemoralis scar by some pterosaurs does not support inclusion of the Pterosauria within the clade Erythrosuchus + Archosauria, whereas the lack of homologous antorbital fossae and a mound-like or aliform fourth trochanter supports exclusion of the Pterosauria from that clade. [ABSTRACT FROM AUTHOR]