PTEROSAUR TRACKS AND THE TERRESTRIAL ABILITY OF PTEROSAURS

Unusual tracks of a quadrupedal animal with a three-digit (occasionall y four-digit) manus print and four-digit pes print were first interpre ted as those of pterosaurs in the 1950s. In the 1980s these tracks wer e reinterpreted as crocodilian, but new material shows that the origin al identification was correct. Two features: evidence for elongate pen ultimate phalanges in digits two to four of the pes, and manus trackwa ys up to three times the width of pes trackways, can only be attribute d to pterosaurs. Recent improvements in understanding of pterosaur ana tomy and functional morphology explain remaining difficulties regardin g the interpretation of ichnites such as the orientation of the manus digits and the absence of some expected ichnological features. Pteraic hnus and Pteraichnus-like tracks show that, when grounded, some, perha ps all, pterosaurs were plantigrade, quadrupedal, and had a semi-erect stance and gait. This is consistent with some functional interpretati ons of pterosaur anatomy and resolves a long-running debate regarding the terrestrial ability of this group.