This work investigates the global distribution and taxonomic composition of Cenozoic mammalian faunas to provide a comprehensive reference for vertebrate paleontology. Authors D. and D. Russell Savage synthesize decades of fossil data to categorize species across major geological periods. The text serves as a systematic framework for researchers to identify and compare mammalian evolution on a worldwide scale, filling a significant gap in scientific literature that had persisted for seven decades prior to its publication.

Experts recognize this volume as a foundational reference for the study of Cenozoic mammals due to its exhaustive scope and detailed documentation. Readers frequently note the academic density of the prose and the utility of the included maps for comparative research.