Were early pterosaurs inept terrestrial locomotors

摘要: Pterodactyloid pterosaurs are widely interpreted as terrestrially competent, erect-limbed quadrupeds, but the terrestrial capabilities of non-pterodactyloids largely thought to have been poor. This is commonly justified by absence a non-pterodactyloid footprint record, suggestions that expansive uropatagia common early would restrict hindlimb motion in walking or running, and presence sprawling forelimbs some species. Here, these arguments re-visited mostly found problematic. Restriction limb mobility not problem faced extant animals with extensive fight membranes, including species which routinely utilise locomotion. The footprints necessarily tied functional biomechanical constraints. As other fully clades poor ichnological records, biases behaviour, preservation, sampling interpretation likely contribute deficit pterosaur ichnites. Suggestions slender, mechanically weak limbs demonstrably countered proportionally long robust many Triassic Jurassic Novel assessments forelimb anatomies conflict notions all were obligated postures. Sprawling seem appropriate for ventrally-restricted glenoid articulations (seemingly occurring rhamphorhynchines campylognathoidids). However, pterosaurs, such Dimorphodon macronyx wukongopterids, arthrologies ventrally restricted, their distal humeri resemble those pterodactyloids. It seems erect stances possible may be probable given proposed correlation between pterodactyloid-like humeral morphology forces incurred through Further indications habits include antungual sesamoids, occur manus pes anatomy species, only elsewhere reptiles, possibly developing frequent interactions large claws firm substrates. argued characteristics associated terrestriality deeply nested within Pterosauria restricted Pterodactyloidea previously thought, levels competency at least pterosaurs.