Book review – The Princeton Field Guide to Dinosaurs (Third Edition)

10-minute read
keywords: evolutionary biology, paleontology

If you have ever seen a diagram of a dinosaur skeleton in a book or scientific paper—white bones, black silhouette, I am looking at you—odds are that it was drawn by independent palaeontologist and palaeoartist Gregory S. Paul, or at the very least inspired by his work. As a consultant and illustrator-for-hire, he has been researching and drawing these diagrams for over 40 years, and The Princeton Field Guide to Dinosaurs brings together the largest such collection in print. I have previously reviewed his companion volumes on pterosaurs and extinct marine reptiles, which is coming at it somewhat the wrong way around. His tenure with Princeton University Press started back in 2010 with the first edition of this dinosaur guide, followed by the second edition in 2016, and the third edition in May 2024. High time, thus, to make up for that lack of review coverage. In the process, I will address the question of whether buyers of the second edition should upgrade.

The Princeton Field Guide to Dinosaurs, written by Gregory S. Paul, published by Princeton University Press in May 2024 (hardback, 384 pages)

If the idea of a field guide to extinct creatures sounds contradictory, think of them as illustrated guides for the palaeo-enthusiast. To recap, Princeton has thus far published guides to dinosaurs, pterosaurs, extinct marine reptiles, theropods (all by Paul), and prehistoric mammals (which features few skeletal reconstructions, though). A very welcome addition later this year will be a guide to Mesozoic plants, which are often neglected in palaeoart. All these books are large format hardbacks (216 × 279 mm) and make for an imposing set on your shelves. For his books, Paul has chosen a template and stuck with it: this third edition, like the previous ones and his other books, follows the same format, with many sections almost identically worded. As before, the book breaks down into an introduction to dinosaur biology (82 pages) and the species accounts (288 pages).

The introduction will set you up with everything you need to know, covering the history of research, a description of the Mesozoic world and its inhabitants, the era’s mass extinctions, a series of palaeogeographical maps, the steps involved in becoming a fossil, and the reverse steps to successfully excavate these. As before, Paul entertains some speculative zoology, imagining a spot of time travel for a dinosaur safari, and asking what might have happened had the asteroid missed and how we might interact with dinosaurs today. Most of the introduction is an extended primer on all aspects of dinosaur biology, including anatomy, appearance, locomotion, physiology, sensory biology, behaviour, reproduction, and the evolution and loss of flight.

One thing to note is that Paul does not provide citations to back up claims and includes only the briefest of recommended reading sections; this book aims to be neither textbook nor encyclopedia. Readers will want to keep in mind, as alluded to in previous reviews, that Paul has opinions and is not afraid to use them. Now, I think there is little here that will set you on the wrong foot; it is just that context as to how widely accepted his views are is not always present. Did an asteroid wipe out the dinosaurs? He thinks that extinction-by-asteroid, or even the combination of impact and Deccan volcanism, are problematic scenarios given everything else that survived. He settles for the not unreasonable conclusion that the mechanisms driving the K–Pg extinction “remain incompletely understood” (p. 28), which is more circumspect than you will typically encounter. He favours the presence of soft tissues such as lips—showing exposed teeth in palaeoart “may be an error as big as it is common” (p. 28)—which I would agree with, but equally confidently writes that birds have a poor sense of smell, to which I would object. A really interesting claim I have not seen elsewhere concerns the evolution of flight, or more accurately, its frequent loss early on. The conventional view that secondary loss was limited to birds proper “is critically flawed because the possibility that weak early fliers rarely if ever lost flight over the nearly 100 million years of the Late Jurassic and Cretaceous is not viable; it would have been happening all the time” (p. 66). He points to various anatomical features in non-fliers and thinks that “attempts to explain them as exaptations before the evolution of flight are at best speculative” (p. 66).

“[…] it is clear that a huge amount of work has gone into compiling all this information. Imbibing it all for days on end brings about a Gestalt shift in your perception of dinosaurs.”

The field guide section arranges taxa phylogenetically, though given that this is forever in flux, he has again “used a degree of personal choice and judgment to arrange the groups and species within the groups. Some of these placements reflect my considered opinion, while others are arbitrary choices between competing research results” (p. 76). Some 1700 species names are in circulation, but a substantial number of these are invalid, duplicated, or based on inadequate remains, so Paul limits himself to some 800 generally accepted ones that have sufficient fossil material behind them. Species are again described in telegram-style entries, listing size and weight estimates, known fossil remains, anatomy, geological age, location and geological formation of fossils, habitat, lifestyle, and other notes. This is the reference section of the book, collecting facts without a guiding narrative. Where sufficient material is available, he provides his signature drawings of skulls or (partial) skeletons, as well as the occasional life reconstruction. The few palaeoart pieces are, to my taste, still a mixed bag, though I liked some of these much better. There are no photos of fossils.

Having spent the last 13 days spelling out this book, it is clear that a huge amount of work has gone into compiling all this information. Imbibing it all for days on end brings about a Gestalt shift in your perception of dinosaurs. Any lingering notion of these as mythical monsters is swept away, replaced by a blossoming of biodiversity over millions of years, with evolution producing many and sometimes wild variations on themes. Some other impressions I came away with are just how many species are based on fragmentary fossils. Especially the skeletal diagrams, which make a point of showing only the bones we have, drive this point home. Very few illustrations are marked as composites. Related to this is the nomenclature: it is easy for each fossil discovery to get its own name, and the impression is of names serving more as specimen labels than representing distinct biological entities. This is how it is possible for Paul to write that several fossils assigned different names might represent different sexes or age groups of a single species. Species concepts are a notoriously tricky topic in biology, and applying them to fossils represents an additional challenge. Only a very small number of entries mention fossil evidence for behaviours, reinforcing that studying this is a speculative affair. Simultaneously, it is a testament to the hard work of generations of researchers that we have learned so much from such challenging material.

Given that I own the second edition, I compared the two in some detail for this review. The one-liner is that the third edition is not a drastically different book but is more of the same. Lest that sound negative: more is good. Increasing from 360 to 384 pages, the third edition has been expanded and revised throughout, the changes many and subtle. This, of course, sounds like the generic claim every publisher makes about new editions, but rather than regurgitating my changelog, which would be as riveting as reading the phone book, let me provide a select few examples.

“I compared [editions two and three] in some detail for this review. The one-liner is that the third edition is not a drastically different book but is more of the same. Lest that sound negative: more is good.”

The first part, in replicating the previous edition word for word, quickly reveals where Paul has inserted additional paragraphs or rewritten sections, discussing e.g. proposals for new top-level taxonomical arrangements such as Ornithoscelida, new details about the asteroid impact and the discovery of the site that seems to have recorded the last day of the dinosaurs, or the novel use of bone biomolecules to restore metabolic rates. In the field guide section, I noticed updates to size, mass, and age estimates throughout. Paul has introduced new divisions: prosauropods now holds baso-prosauropods and euprosauropods, while maniraptors and paravians have been eliminated in favour of a new group called airfoilans (one of the few examples of a semi-formal taxonomical proposal made here). There are well over 50 new species, e.g. Latenivenatrix mcmasterae (the current largest-known troodont), or the awesomely named ankylosaurid Minotaurasaurus ramachandrani (previously considered a juvenile of Tarchia kielanae). The alvarezsaurid Kol ghuva has been removed, while the lambeosaur Sahaliyania elunchunorum is now considered a juvenile of Amurosaurus (or Hypacrosaurus) riabinini. Some groups have been thoroughly reshuffled: a large number of species have been moved from baso-titanosaurids to lithostrotians, and from ankylosaurids to nodosaurids. There are new illustrations (a skeletal diagram of the euprosauropod Macrocollum itaquii) and expanded ones (the baso-tetanuran Cryolophosaurus ellioti has gone from a skull to a partial skeleton). You could even play “spot the difference”: the skeleton of the basotheropod Tawa hallae now features gastralia and a sclerotic ring, while the entry for the baso-eusauropod Spinophorosaurus nigerensis mentions that reconstructions showing tail spikes are incorrect. Looking at the second edition, this reads like a mental note to self, as he has removed the tail spike and tail tip that he previously drew.

Given that many readers might already possess an older version, should you spend the money to upgrade? If you are still rocking a copy of the first edition, what are you still doing here? But what about going from second to third? It all depends on your mileage with the second edition. For casual readers, this is going to be a personal choice dictated by, e.g. shelf space and liquidity. Unless you are a completist who must have every good dinosaur book, maybe you want to hold on to your money and check out the (*drumroll*) three-volume dinosaur encyclopedia that Princeton announced for later this year. If, however, the above changes sound meaningful and relevant to you, then you are in the market for the third edition. For palaeontologists or palaeoartists who regularly consult their current copy, the choice is straightforward: you need to upgrade. If you happen to be new to these books and are looking for a detailed reference work to as many dinosaurs as possible, or need scientifically sound illustrations, look no further. Paul’s drawings are a benchmark in the discipline, and this guide is a mouth-watering cornucopia of detailed skeletal diagrams.

I was going to conclude that, after three books, Paul has completed a remarkable trilogy of guides to all extinct Mesozoic reptiles and has shown laudable perseverance in updating the dinosaur guide not once, but twice, to keep it current. However, only six months later, Princeton published The Princeton Field Guide to Predatory Dinosaurs. What is this all about? Does it contain anything new? Is the dinosaur guide not as complete as it claims to be? Stay tuned for a follow-up review soon.

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

The Princeton Field Guide to Dinosaurs (3rd edition)