Appendicular skeleton of Protoceratops andrewsi (Dinosauria, Ornithischia): comparative morphology, ontogenetic changes, and the implications for non-ceratopsid ceratopsian locomotion

Protoceratops andrewsi is a well-known ceratopsian dinosaur from the Djadokhta Formation (Upper Cretaceous, Mongolia). Since the 1920s, numerous skeletons of different ontogenetic stages from hatchlings to adults, including fully articulated specimens, have been discovered, but the postcranial anatomy of Protoceratops has not been studied in detail. A new, mostly articulated subadult individual provides an excellent opportunity for us to...