Cranial Morphology in North American Edmontosaurs
2011

Cranial Growth and Variation in Edmontosaurs: Implications for Latest Cretaceous Megaherbivore Diversity

Sample size: 23 publication Evidence: high

Author Information

Author(s): Nicolás E. Campione, David C. Evans

Primary Institution: University of Toronto

Hypothesis

What is the diversity of edmontosaur species leading up to the end Cretaceous extinction event?

Conclusion

The study suggests that only two valid species of Edmontosaurus existed, indicating a decline in hadrosaurid diversity before the extinction event.

Supporting Evidence

  • Only two valid species of Edmontosaurus were identified.
  • Hadrosaurid diversity decreased from the early to late Maastrichtian.
  • Previous interpretations of edmontosaur diversity were based on flawed taxonomic schemes.

Takeaway

Scientists studied dinosaur skulls to find out how many types of Edmontosaurus there were, and they discovered there were only two kinds, not as many as thought.

Methodology

The study used morphometric analyses of complete edmontosaur skulls to assess species diversity and biostratigraphy.

Potential Biases

Potential biases may arise from the subjective nature of taxonomic assessments.

Limitations

The study could not test for fine-scale stratigraphic segregation of morphological variation due to lack of precise locality data.

Statistical Information

P-Value

p<0.01

Statistical Significance

p<0.01

Digital Object Identifier (DOI)

10.1371/journal.pone.0025186

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