Possible regional tectonic controls on mammalian evolution in western North America

We explore the extent to which these topographic changes influenced or are decoupled from diversity changes exhibited by the local mammal faunas and conclude that the passage of the hotspot and consequent surface uplift created rainshadows in the lee of high-elevation calderas and/or generated large volumes of volcanic materials, influencing soils and vegetation. Collectively, that may explain a possible rise in mammal diversity in the CP/SRP region at ~ 14 Ma, coincident with a drop in diversity in the NRM. It is still unclear, however, how different taphonomic pathways and sample-standardization problems are influencing apparent diversity peaks at this temporal and geographic resolution.