The Story of the Mammals in 25 Discoveries: Amazing Fossils and the People Who Found Them, by Donald R Prothero

Jon Trevelyan (UK)

I have previously reviewed Donald R Prothero’s The Story of Earth’s Climate in 25 Discoveries for Deposits, and one of the things that particularly impressed me about that book was his ability to explain complicated scientific ideas in straightforward, entertaining language. I am pleased to say that this latest volume is every bit as successful in that respect. Prothero has a gift for making palaeontology accessible without oversimplifying the science, ensuring that both beginners and experienced readers have much to enjoy and learn from.

Prothero is particularly well qualified to write this book. Although he has published extensively on a wide range of geological and palaeontological subjects, much of his professional research has concentrated on fossil mammals and their evolution. Consequently, this is a subject he knows intimately, and that expertise is apparent throughout the book.

As the title suggests, the book is organised around 25 discoveries in mammalian palaeontology. Each chapter takes a particular fossil mammal or group of mammals as its starting point, ranging from familiar animals such as mammoths, giant ground sloths and sabre-toothed cats to some of the more extraordinary and less familiar creatures that once inhabited the Earth. Among these are chalicotheres, uintatheres and brontotheres, animals whose unusual appearances and evolutionary histories are fascinating in their own right.

Although the chapter headings suggest that each concentrates on a particular extinct mammal, this is somewhat misleading – and in a very welcome way. Prothero uses the featured animals as starting points for much broader discussions of their relatives and evolutionary histories. Consequently, the reader learns about considerably more than the 25 animals or groups highlighted in the contents. This approach provides valuable context, helping to explain how different mammals evolved, how they were related and what made them distinctive. It is one of the book’s great strengths.

It is also worth clarifying the book’s scope. Although Prothero discusses some of the earliest mammals and their Mesozoic relatives, his principal interest is in the extraordinary diversity of mammals that evolved during the Cenozoic, following the end-Cretaceous mass extinction. Readers hoping for a detailed account of the earlier synapsids, therapsids and other mammalian ancestors will not find it here. However, given the enormous subject matter and the book’s emphasis on particular fossil discoveries, this is an understandable limitation, rather than a serious omission.

One of the most enjoyable features of the book is Prothero’s inclusion of numerous anecdotes about the scientists responsible for the discoveries. These are frequently fascinating and sometimes amusing, bringing the personalities behind the fossils vividly to life. Rather than interrupting the scientific narrative, they complement it beautifully, reminding us that palaeontology is as much a story of human curiosity, ingenuity and occasional eccentricity, as it is of ancient animals. Prothero explores how our understanding of these creatures developed, often through discoveries made by remarkable individuals working in circumstances very different from those of modern palaeontologists. This approach works particularly well, humanising the science and contributing enormously to the book’s readability.

Although I already knew a fair amount about fossil mammals and their evolution, I was pleasantly surprised by just how much new information I encountered. Prothero manages the difficult task of making his subject accessible to complete beginners, without sacrificing the detail that makes it interesting to more knowledgeable readers. I found myself learning something new throughout the book, while thoroughly enjoying the experience. That is no small achievement in a volume of more than 500 pages.

I do have a couple of minor reservations. The first concerns the organisation of the book. By concentrating on individual discoveries, rather than following a chronological sequence, Prothero occasionally makes it difficult to appreciate how the various mammals relate to one another in geological time. I sometimes found myself wondering whether the animals being discussed were contemporaries or separated by millions of years. Although the approach is understandable, a little more attention to the relative ages of the different groups would have helped place their evolutionary histories in context. A simple geological timeline showing when the principal groups lived would have been particularly helpful. However, this is a relatively minor criticism of what is otherwise a thoroughly enjoyable book.

The second reservation concerns the illustrations. The book is generously illustrated with photographs, drawings and reconstructions, all of which help bring the animals and their evolutionary histories to life. However, the illustrations are entirely in black and white, and I couldn’t help feeling that a little colour would have made the book even more appealing. This is a minor disappointment, rather than a serious criticism, since the illustrations generally serve their purpose well.

Neither of these reservations should detract from what is an excellent book. Prothero’s enthusiasm for his subject is apparent throughout, and the breadth of material covered, the fascinating accounts of the discoveries and the sheer variety of extinct mammals discussed make this a consistently rewarding read.

I thoroughly enjoyed The Story of the Mammals in 25 Discoveries and would recommend it without hesitation to anyone interested in palaeontology, evolution or the history of life on Earth. Beginners will find an accessible introduction to an extraordinary group of animals, while those who already know something about fossil mammals will almost certainly discover plenty that is new to them.

Prothero has once again demonstrated that serious palaeontology can be both scientifically informative and genuinely enjoyable to read.

About the author

Donald R Prothero is an American palaeontologist, geologist and prolific science writer. He is an adjunct professor of geological sciences at California State Polytechnic University, Pomona, and a research associate in vertebrate palaeontology at the Natural History Museum of Los Angeles County. His research has focused particularly on fossil mammals, vertebrate evolution and Cenozoic geology; and he has written numerous scientific and popular books on palaeontology, evolution and Earth history.

The Story of the Mammals in 25 Discoveries: Amazing Fossils and the People Who Found Them, by Donald R Prothero, Columbia University Press (2026), 544 pages (hardback), ISBN: 780-231218306