Cranial biomechanics underpins high sauropod diversity in resource-poor environments

David J Button*, Emily J Rayfield, Paul, M. Barrett

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

34 Citations (Scopus)

Abstract

High megaherbivore species richness is documented in both fossil and contemporary ecosystems despite their high individual energy requirements. An extreme example of this is the Late Jurassic Morrison Formation, which was dominated by sauropod dinosaurs, the largest known terrestrial vertebrates. High sauropod diversity within the resource-limited Morrison is paradoxical, but might be explicable through sophisticated resource partitioning. This hypothesis was tested through finite-element analysis of the crania of the Morrison taxa Camarasaurus and Diplodocus. Results demonstrate divergent specialization, with Camarasaurus capable of exerting and accommodating greater bite forces than Diplodocus, permitting consumption of harder food items. Analysis of craniodental biomechanical characters taken from 35 sauropod taxa demonstrates a functional dichotomy in terms of bite force, cranial robustness and occlusal relationships yielding two polyphyletic functional 'grades'. Morrison taxa are widely distributed within and between these two morphotypes, reflecting distinctive foraging specializations that formed a biomechanical basis for niche partitioning between them. This partitioning, coupled with benefits associated with large body size, would have enabled the high sauropod diversities present in the Morrison Formation. Further, this provides insight into the mechanisms responsible for supporting the high diversities of large megaherbivores observed in other Mesozoic and Cenozoic communities, particularly those occurring in resource-limited environments.

Original languageEnglish
Article number20142114
Number of pages9
JournalProceedings of the Royal Society B: Biological Sciences
Volume281
Issue number1795
DOIs
Publication statusPublished - 22 Nov 2014

Keywords

  • niche partitioning
  • megaherbivores
  • sauropod
  • Morrison Formation
  • biomechanics
  • finite-element analysis
  • FINITE-ELEMENT-ANALYSIS
  • ANTERIOR PRESACRAL REGION
  • MAMMALIAN HERBIVORES
  • MAMMOTH STEPPE
  • WESTERN USA
  • BODY-SIZE
  • DINOSAURS
  • NECK
  • PERFORMANCE
  • EVOLUTION

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