The Aaron Scott Site dinosaur quarry (Quarry) in the Morrison Formation of Utah offers a unique view of Late Jurassic patterns of terrestrial diversity. The Quarry represents a rare perennial lacustrine environment of deposition, preserving a diverse population of large and small vertebrate and invertebrate fauna.
The null hypotheses state that patterns of diversity at the Quarry do not differ significantly from those found at ephemeral lacustrine sites elsewhere in the Morrison, and an even spread of terrestrial diversity across the Late Jurassic Morrison Basin.
While evidence has revealed a similarity between the Quarry and ephemeral lacustrine sites, multivariate analysis reveals distinct patterns in terrestrial diversity of the Morrison Formation, most prominently, a division between wetland and dry land taxa, and between ornithischian and sauropod dominated environments. Unusual patterns found among several taxa pairs hint that two (or more) Morrison genera may be sexual dimorphs or organisms at different stages in their ontogeny. While the Quarry itself may not be wholly unique, the Morrison was far more complex than traditionally portrayed.