This volume investigates the fundamental principles of paleontology, examining how fossilized remains serve as the primary evidence for the history of life on Earth. H. H. Swinnerton, a distinguished geologist and paleontologist, utilizes his extensive academic background to synthesize complex biological and geological data. The text provides a structured framework for understanding the processes of fossilization, the classification of ancient organisms, and the interpretation of evolutionary sequences within the geological record.

The subject matter points to a dense, specialist text that serves as a foundational reference for students and enthusiasts of natural history. Its inclusion in the long-standing New Naturalist series suggests a rigorous, scholarly approach to the study of ancient life forms and their geological context.