Abstract
Sauropodomorpha represents an important group of Mesozoic
megaherbivores, and includes the largest terrestrial animals ever known.
It was the first dinosaur group to become abundant and widespread, and
its members formed a significant component of terrestrial ecosystems
from the Late Triassic until the end of the Cretaceous. Both of these
factors have been explained by their adoption of herbivory, but
understanding the evolution of sauropodomorph feeding has been hampered
by the scarcity of biomechanical studies. To address this, the jaw
adductor musculature of the basal sauropodomorph Plateosaurus and the sauropod Camarasaurus
have been reconstructed. These reconstructions provide boundary
conditions for finite element models to assess differences in structural
performance between the two taxa. Results demonstrate that Camarasaurus was capable of much greater bite forces than Plateosaurus, due to greater relative adductor muscle mass and shape changes to the mandible. The skull and mandible of Camarasaurus are also ‘stronger’ under static biting. The Plateosaurus
mandible appears to compromise structural efficiency and force
transmission in order to maintain relatively high jaw closure speed.
This supports suggestions of facultative omnivory in basal
sauropodomorph taxa. The expanded mandibular symphysis and ‘lateral
plates’ of sauropods each lead to greater overall craniomandibular
robustness, and may have been especially important in accommodating
forces related to asymmetric loading. The functional roles of these
characters, and observed general shape changes in increasing skull
robustness, are consistent with hypotheses linking bulk-herbivory with
the origin of Sauropoda and the evolution of gigantism.
Original language | English |
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Pages (from-to) | 887-913 |
Number of pages | 27 |
Journal | Palaeontology |
Volume | 59 |
Issue number | 6 |
Early online date | 28 Oct 2016 |
DOIs | |
Publication status | Published - Nov 2016 |
Keywords
- Sauropodomorpha
- finite element analysis
- herbivory
- palaeoecology