This volume investigates the taxonomic classification and stratigraphic distribution of fossil ungulates found within the Pliocene and Pleistocene sediments of the Koobi Fora region in Kenya. J. M. Harris utilizes extensive field data collected from geological investigations to categorize remains of hippopotamuses, camels, giraffes, and antelopes. By synthesizing these findings with existing palaeogeographic data, the author establishes a framework for understanding the environmental shifts that occurred alongside hominid development in the region.

Experts recognize this work as a foundational reference for researchers focusing on East African paleoecology and hominid site formation. The text is noted for its high degree of technical density and its reliance on primary stratigraphic data.