Predicting the Distribution of the Extinct Sea Bird Hesperornis

In the Late Cretaceous, North America was divided by a shallow epicontinental sea known as the Western Interior Seaway. Native life included various marine reptiles, fish, ammonites, and seabirds such as Hesperornis . Previous research has applied ecological niche modeling to discuss competition among large vertebrates in the seaway (mosasaurs and predatory fish) but ignored small vertebrates. The present study combined localities of Hesperornis fossils with sea surface temperature estimates to characterize the distribution of Hesperornis in the upper Great Plains. Temperature interpolation in ArcGIS and niche analysis in Maxent predicted that Hesperornis preferred warmer marine waters (highest suitability values) and may support the hypothesis that Hesperornis migrated between the paleo Arctic and the lower Western Interior Seaway. Most of the study area, however, is homogenous in suitability, indicating the results are largely inconclusive. Additional ecosystem variables (e.g., biological interactions and rock type) will be applied in future analyses to describe the distribution of Hesperornis