Comparative cranial myology and biomechanics of Plateosaurus and Camarasaurus and evolution of the sauropod feeding apparatus

摘要: Sauropodomorpha represents an important group of Mesozoic megaherbivores, and includes the largest terrestrial animals ever known. It was first dinosaur to become abundant widespread, its members formed a significant component ecosystems from Late Triassic until end Cretaceous. Both these factors have been explained by their adoption herbivory, but understanding evolution sauropodomorph feeding has hampered scarcity biomechanical studies. To address this, jaw adductor musculature basal Plateosaurus sauropod Camarasaurus reconstructed. These reconstructions provide boundary conditions for finite element models assess differences in structural performance between two taxa. Results demonstrate that capable much greater bite forces than Plateosaurus, due relative muscle mass shape changes mandible. The skull mandible are also ‘stronger’ under static biting. appears compromise efficiency force transmission order maintain relatively high closure speed. This supports suggestions facultative omnivory expanded mandibular symphysis ‘lateral plates’ sauropods each lead overall craniomandibular robustness, may especially accommodating related asymmetric loading. functional roles characters, observed general increasing consistent with hypotheses linking bulk-herbivory origin Sauropoda gigantism.