Author's signature by G.G. Simpson, with a dedication to Oldřich Fejfar, a prominent Czech paleontologist and geologist, specializing in prehistoric mammals. He lived during the 20th century and contributed significantly to the development of paleontology in Czechoslovakia. His work mainly focused on fossils of mammals and their evolution. Fejfar also worked as an academic and authored numerous scientific publications. He is regarded as an important figure in paleontological circles, helping to expand knowledge about prehistoric life in Central Europe. George Gaylord Simpson (1902–1984) was a pioneering American paleontologist and one of the most influential evolutionary biologists of the 20th century. He made significant contributions to the understanding of mammal evolution and played a key role in developing the modern synthesis of evolutionary theory. Simpson’s work combined fossil evidence with genetics, helping to bridge gaps between paleontology and biology. His research remains foundational in the study of evolution. Condition: Only slightly worn edges of the dust jacket; otherwise, the overall condition of the book is very good.