Book review – The Princeton Field Guide to Predatory Dinosaurs

10-minute read
keywords: evolutionary biology, paleontology

Independent palaeontologist and palaeoartist Gregory S. Paul is well-known for his scientifically informed diagrams of dinosaur skeletons. Over the course of four decades, he has perfected this style of infographic, showing white bones laid out on the black silhouette of a body. After writing and illustrating three editions of The Princeton Field Guide to Dinosaurs and two companion volumes on pterosaurs and extinct marine reptiles, I was ready to congratulate him on a job well done. He has collated arguably the largest collection of skeletal reconstructions of extinct Mesozoic reptiles in print. Imagine my surprise, then, when Princeton published this book on predatory dinosaurs only six months after the most recent iteration of the dinosaur guide. But… hang on. Does that mean that the dinosaur guide is not as complete as claimed? Have there been that many developments that a separate book is already warranted? I am confused by this book: time for an in-depth comparison.

The Princeton Field Guide to Predatory Dinosaurs, written by Gregory S. Paul, published by Princeton University Press in November 2024 (hardback, 256 pages)

In this review, I will only briefly describe the book’s contents and assume that you are already familiar with Paul’s earlier Princeton guides. Do please check out any of my previous reviews if you are new to this, otherwise, you know what to expect. Here, I will focus on two comparisons that, I hope you will agree, are relevant to prospective buyers: first, to his original Predatory Dinosaurs of the World and, second, to the just-published third edition of The Princeton Field Guide to Dinosaurs.

To recap: as before, this book consists of two parts. The introduction contains the usual extended primer on all aspects of, here, predatory dinosaur biology, including anatomy, appearance, locomotion, physiology, sensory biology, behaviour, reproduction, and the evolution and loss of flight. This is complemented by relevant background information on the history of research, a description of the Mesozoic world and its inhabitants, the era’s mass extinctions, a series of palaeogeographical maps, the process of fossilisation and excavation, and Paul’s imagined zoological what-if scenarios. The field guide arranges taxa phylogenetically, relying as before on “a degree of personal choice and judgment” (p. 96), and provides the familiar telegram-style entries, listing size and weight estimates, fossil remains, anatomy, age, distribution and geological formation, habitat, habits, and other notes. This is the reference section of the book, collecting facts without a guiding narrative. For species where there is sufficient material available, his signature diagrams of skulls or (partial) skeletons are given, together with the occasional life reconstruction. There is a refreshed selection of colour and black-and-white palaeoart throughout the book.

Those who are getting long in the tooth might remember Paul’s first book with Simon & Schuster in 1988, Predatory Dinosaurs of the World: A Complete Illustrated Guide (PDW for short). It acquired somewhat of a legendary status, though my eight-year-old self completely missed the boat, and I only recently bought a copy second-hand. Remarkably, Paul does not mention what motivated him to write the current book or how it relates to PDW. He acknowledges its existence only once in the section on the history of palaeontology, briefly stating that it “covered the same basic subject as this field guide” (p. 11).

“I will focus on two comparisons that […] are relevant to prospective buyers: first, to his original Predatory Dinosaurs of the World and, second, to […] The Princeton Field Guide to Dinosaurs“

This first comparison is thus straightforward. PDW is a charming and chunky book of smaller trim size but larger page count (464 then vs. 256 now). Flipping through it, a lot of the artwork and diagrams look familiar and were later reused or redrawn in much crisper detail. The field guide section contains many more technical details, such as museum specimen numbers and, for the more complete specimens, dimensions such as skull length, femur length, and hip height. Obviously, the number of known species has increased dramatically and there have been numerous changes to the taxonomical and biological details, so the book is a time capsule. However, do not get rid of your copy just yet! The narrative entries for each species contain historical information and technical details that would not be repeated in later books. In a way, that is a shame, but I can see that redoing the current book in the same style would have been a mammoth undertaking, resulting in a large book that probably would have been neither commercially viable nor of general interest. Now, if all we had was PDW, I would have no hesitation in recommending The Princeton Field Guide to Predatory Dinosaurs as a long overdue and much-needed update. However, that is not the world we live in.

This brings me to the second comparison. Having just reviewed the third edition of The Princeton Field Guide to Dinosaurs (D3E) and compared it to the second edition (D2E), I have done a similar page-by-page comparison between this book and D3E. Before we proceed, I want to emphasise that I have no qualms with any of the material itself: it is of the same high quality as found in D3E, but that is because most of it is found in D3E.

The introductory sections have been updated in numerous places, but some of these are rather inconsequential, omitting sections on ornithischians and sauropods, updating examples so they mention theropod genera and species, and replacing references to “dinosaurs” with “dinopredator” or “avepod”. In places, there are additional sentences or paragraphs with some extra information. but, by my rough estimate, some 90–95% of the text is identical. The only substantial additions are a 13-page section on hunting, scavenging, defence, and the occasional herbivory; and an expanded section on the evolution of flight that adds roughly a page of text. That section sees him double down on the idea that flight was secondarily lost numerous times: “Early flight loss not being the frequent norm is an extraordinary hypothesis that requires correspondingly extraordinary evidence in the tradition of the Carl Sagan axiom” (p. 83). The selection of diagrams and illustrations has been updated, remixed, and refreshed in many places, though quite a few images are found in earlier books. For example, Lewisuchus admixtus with prey (p. 20), the diagram with running animals (p. 44), the swimming Dilophosaurus (p. 45), and various others all featured in PDW but have been slightly modified. The diagram with eggs and nests (p. 59) leaves out non-theropod eggs but adds some nest layouts missing from D3E that were present in D2E.

“Casually flicking through [the field guide section], you would be forgiven for thinking this is literally The Princeton Field Guide to Dinosaurs‘ theropods section, but that is not quite true.”

For the field guide section, the situation is much the same. Casually flicking through it, you would be forgiven for thinking this is literally D3E‘s theropods section, but that is not quite true. Although all the groups are discussed in the same order, after carefully comparing and cross-referencing with the index in D3E, I came up with the following tally:
– two species (Rahiolisaurus gujaratensis and Ceratonykus oculatus) have been demoted to the notes section of other entries;
– five species have changed affiliation, e.g. Nedcolbertia justinhofmanni now being placed in baso-ornithomimosaurs rather than neocoelurosaur miscellanea;
– seven species have changed names, e.g. Allosaurus? europaeus previously being listed as “Lourinhanosaurus antunesi and/or Allosaurus? europaeus“;
– twelve species previously only mentioned in notes have been upgraded to separate entries (eleven of these are based on fragmentary remains);
This is all housekeeping. More consequential are the 71 species not previously mentioned in D3E, though only nine are based on substantial remains or multiple skeletons; the other 62 are based on fragmentary or partial remains, meaning there is often “insufficient information” on anatomy. Whether these names will stand the test of time remains to be seen. It is also unclear where they came from, as Paul does not indicate whether they are new discoveries since the publication of D3E or whether he has used less stringent selection criteria for this book. This leaves around 230 species that were already present in D3E. Although I did not systematically check all the details for each one, most appear identical. For some of the better-known species and groups, additional notes have been added, and I noticed only one species, Hesperornithoides miessleri, where size and weight estimates have been updated compared to D3E, as more fossil remains have become available.

What about the skeletal diagrams, arguably the unique selling point of these books? The vast majority of these are the same. I counted three new skull restorations (Allosaurus? europaeus, Nanotyrannus lancensis, and Lythronax argestes), for a new total of 45; three new skeletal restorations (Saurornitholestes langstoni, Jaculinykus yaruui, and Oksoko avarsan), for a new total of 110; and eight diagrams with added fore-and-aft views. Four other skeletal diagrams were taken from elsewhere in D3E (“Stygivenator? unnamed species” and “Nanotyrannus or unnamed genus and unnamed species” from the Tyrannosaurus imperator growth series, and Lagosuchus talampayensis and Lewisuchus admixtus from a composite image of protodinosaurs on p. 18 of D3E). Additionally, there are nine new colour pieces, one additional shaded skull, and one additional muscle study.

Totting it all up, the outcome of this exercise is somewhat frustrating. There is new material in this book: notably a new section on feeding biology, an expanded section on flight evolution, six new skeletal diagrams, some new palaeoart, 71 new species (most of them based on fragmentary remains), and sundry smaller edits and changes. To be honest, however, given the amount of duplicated material, and seeing how substantial the update from D2E to D3E was, this represents slim pickings, even for completists. To reiterate, it is not the material itself I take issue with, but how much of it was published just six months prior. Owners of D3E are justified in asking whether such a derivative book is a good use of their limited funds and shelf space, while others might just as well spend a little bit extra to get all dinosaurs between the covers of one book. These updates could, and should, have been included in D3E. This would have made D3E somewhat larger, yes, but seeing the announcement of a 3-volume dinosaur encyclopedia, Princeton believes that there is a market and appetite for large dinosaur books. Alternatively, they could have formed the basis for a future fourth edition.

Unfortunately, as I was wrapping up this review, I noticed that Paul’s website announces plans for separate field guides to sauropods and ornithischians as well. Given his formulaic approach so far, I fear that this would result in three books sharing very similar introductions between them while largely duplicating the field guide section of D3E. Such repackaging of material is not something I am in favour of, and, in my opinion, time and effort would be better spent working towards the fourth edition of the dinosaur guide.

Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

The Princeton Field Guide to Predatory Dinosaurs