Size-mediated competition and community structure in a Late Cretaceous herbivorous dinosaur assemblage

It has been argued that, throughout the Mesozoic, immature growth forms of megaherbivorous dinosaurs competitively excluded small herbivorous dinosaur species, leading to left-skewed species richness-body mass distributions their fossil assemblages. By corollary, where large and herbivores coexisted over a geologically significant period time, they must have exhibited niche partitioning. We use multivariate ecomorphological analysis Late Cretaceous ornithischian assemblage North America examine this prediction. Our results indicate good separation most, but not all, at body size, although more work is required demonstrate that these patterns were adaptive. Calculation browse profiles using corrected abundance data bracketed estimates energy requirements suggests megaherbivores – most particularly hadrosaurids outstripped coexisting in control resource base.