Pterosaurs: back to the traditional model?

For most of the past 200 years, pterosaurs have been reconstructed with wing membranes attached to both the forelimbs and hindlimbs and with a quadrupedal stance and gait when grounded. In the early 1980s, this traditional model was replaced by a new design with narrow, stiff wings confined to the forelimbs and an upright, bipedal, digitigrade stance and gait. However, new studies of complete, uncrushed skeletal remains, well preserved wing membranes and extensive new pterosaur tracks, combined with reanalysis of the relationships of pterosaurs to other reptiles, suggest that a return to the traditional model is now overdue.