Final answer:
Plesiadapiforms had a wide geographic range and diverse taxonomic attributes, which may have included various body sizes and dietary preferences. Smaller geographic ranges likely correlated with lower local abundance, while larger ranges may have conferred greater species resilience.
Step-by-step explanation:
The geographic range of the Plesiadapiforms refers to the areas where these prehistoric mammals could be found. Their remains suggest that their range was widespread across various continents. The taxonomic diversity of Plesiadapiforms indicates a varied group of species within this category of early mammals. Examples of taxonomic diversity can be seen in their varying body sizes, dietary preferences, and adaptations, indicating that Plesiadapiforms evolved into multiple forms to occupy different ecological niches.
Regarding the local abundance of species with small ranges, it is established that species with smaller geographic ranges tend to be less abundantly found within their habitats, which may similarly have been true for Plesiadapiforms with restricted ranges. In considering the principles of species richness and range expansion mentioned in the reference literature, Plesiadapiforms with more extensive ranges might have experienced lower rates of extinction and possibly greater taxonomic diversity.