ABSTRACT

Plateosaurus from the late Triassic of Central Europe is one of the best known dinosaurs. Despite the large number of finds, including complete and articulated skeletons, its posture and locomotion capabilities are still being debated. While recent assessments of the range of motion of the forelimb indicate that Plateosaurus was incapable of manus pronation, and thus an obligate biped, practically all other possible alternatives have been suggested in the literature. Here, I present evidence, derived from a detailed mounting of a 3D digital skeleton and a computer-aided engineering assessment of a digital 3D model of the living animal, that Plateosaurus was indeed an obligate biped. The position of the center of mass is assessed in several variations of the basic model to account for differing interpretations of soft tissue amounts. All models allow a stable bipedal pose with a subhorizontal back that is consistent with the requirements of both slow and rapid locomotion. Quadrupedal models, in contrast, suffer from locomotion restrictions due to highly uneven limb lengths and a limited motion range in the forelimb, and result in a smaller feeding envelope.

Heinrich Mallison, Glambecker Weg 6, 13467 Berlin, Germany

KEY WORDS: Plateosaurus, locomotion, virtual skeleton