I have written previously that deducing behaviour of extinct animals from fossils millions of years old might seem science fiction, but is very much science fact. That said, in his previous book, English palaeontologist David Hone pointed out that dinosaur behaviour is the one area where we see the greatest disconnect between what we know and what people think we know. His new book Uncovering Dinosaur Behavior is a sobering reality check for the lay reader, but I suspect that even palaeontologists might come away wondering whether there is anything we know for sure. Concise, well-structured, and beautifully illustrated by palaeoartist Gabriel Ugueto, this is a superb book that transcends “merely” being a good popular science work by also addressing professional palaeontologists.

Uncovering Dinosaur Behavior: What They Did and How We Know, written by David Hone, published by Princeton University Press in November 2024 (hardback, 232 pages)

Uncovering Dinosaur Behavior opens with a very clear mission statement: what the book is and is not about, who it is for, and even what its potential weak points are. Hone writes about dinosaur behaviour, yes, but this is more than a catalogue of studies showing that species X likely did behaviour Y. He is aiming for a more integrated work, explaining how we figured these things out and offering advice on how to resolve conflicting results and answer remaining questions. His target audience encompasses dinosaur enthusiasts, of course, but he is additionally aiming at both palaeontologists interested in animal behaviour and ethologists interested in dinosaurs. He is upfront about the potential weaknesses: in trying to serve several masters, he might please none. Furthermore, he unapologetically follows the biases of the existing literature that emphasizes the charismatic megafauna at the expense of a broader take on dinosaurs at large. Having explicitly laid his cards on the table, Hone follows through with a logically structured book.

Three introductory chapters cater to both palaeontologists and ethologists by providing primers on dinosaurs, the fossil record, and the study of animal behaviour. You will find both a helpful appendix briefly introducing all major dinosaur lineages, and an introduction to Niko Tinbergen’s four famous questions of why an animal behaves the way it does that became the foundation for ethology. One of the chapters introduces the basic biology that both determines and limits dinosaur behaviour; topics such as activity patterns (when during the day are you active?), habitat choice, physiology, posture, and locomotion. A final important concept is extant phylogenetic bracketing, that is, looking at the behaviour of the nearest living relatives of dinosaurs (birds, crocodilians, and reptiles more widely). This will help you determine how far back in time a certain behaviour likely evolved. Armed with all of the above, you should be better able to judge whether behaviours inferred for dinosaurs are theoretically possible, plausible, or even likely.

Hone here also lays out his challenge to fellow palaeontologists to produce more rigorous science, giving you a set of eleven guidelines that he published together with Chris Faulkes in a 2014 paper. He has observed several recurrent problems with how data is used, interpreted, and presented, leading to misrepresentation and over-extrapolation of behaviour far beyond what the data supports. His philosophy is to “always favor a degree of uncertainty or lack of confidence in a result, rather than embracing an interpretation confidently that may be wrong” (p. 35).

“[The] target audience encompasses dinosaur enthusiasts, of course, but he is additionally aiming at both palaeontologists interested in animal behaviour and ethologists interested in dinosaurs.”

The remainder of the book examines five broad categories of behaviours. Given what I just wrote about Hone’s attitude to the research field, I can now explain why I introduced this book as a sobering reality check. Take the frequently depicted idea that dinosaurs lived in groups, with a certain franchise making hay out of pack hunting. Now, many animals alive today live socially, and there are advantages to doing so, but how do you deduce this from fossils? The problem with bonebeds is that fossils found in groups did not necessarily live or even die together: the taphonomic history (what happened between death and burial) matters. But equally, many groups will have lost members individually: solitary fossils do not exclude social behaviour. Trackways can similarly not be taken at face value. Beyond the challenge of assigning them to species, determining if they were laid down together is challenging, and even if they were, many interpretations are possible beyond social behaviour.

Hone is similarly circumspect when it comes to signalling and reproduction. He highlights what we know and what remains unknown. For instance, dinosaurs likely used visual and auditory signals, and they laid eggs. But did they use touch, taste, or smell? How did they mate? How many eggs did a female typically lay? What amount of care did parents bestow on offspring before and after hatching? We have data and tentative hints for some species, but for many questions, we cannot go much beyond generalities. The situation is better for combat: many species sported implements that intuitively look like weapons, but how and on whom they used them is harder to determine. Studies have furthermore focused on a small number of species while ignoring many others. Feeding biology is the area that has the most robust support, bringing together many independent lines of evidence such as biomechanics, trace fossils, isotope data, tooth microwear analysis, stomach contents, and coprolites. Even here, though, such full pictures are only available for a handful of species.

Overall, interpreting dinosaur behaviour is “profoundly difficult” (p. 152) due to both the limitations of the fossil record and the diversity and plasticity we see in the behaviour of animals alive today. The problem he observes is that “much of the scientific literature tends toward a confidence in interpreting dinosaurian behaviors that probably should not be there [while failing] to recognize alternate possibilities and the inherent uncertainty of interpreting ancient behaviors” (p. 153). That sounds pretty damning but he also recognizes that the field has come a long way from early guesswork and extrapolations to more rigorous methods that take seriously the fact that dinosaurs were once real, living animals rather than mythical monsters.

“Hone’s work […] hit the sweet spot of the kind of depth I look for in my popular academic books: fairly technical, thought-provoking, never shirking the hard questions, and yet admirably brief”

Compared to the previously reviewed The Future of Dinosaurs, which had a somewhat haphazard ordering of its chapters, Uncovering Dinosaur Behavior benefits from an excellent and logical structure that flows very well. However, some noticeable typos did slip through again, despite the extensive proofreading. All chapters come with a helpful summary and an interesting case study; I thought the one on ankylosaurs and what their tail clubs were used for was particularly compelling. I also have to praise the fantastic illustrations by Ugueto. The colour plate section is mouthwatering eye candy, and there are numerous classy and useful black-and-white drawings and diagrams throughout the book. Some of the black-and-white photos of fossils are harder to decipher, and I would not have minded had some been included in the colour plate section.

Uncovering Dinosaur Behavior was published about a year after Michael J. Benton’s Dinosaur Behavior: An Illustrated Guide, meaning Princeton University Press now has two illustrated books on this topic. Which one do you choose? In my review, I highlighted that Benton’s is an introductory book for novices that starts from first principles. Hone’s work, though very accessible, is more advanced and, for me, hit the sweet spot of the kind of depth I look for in my popular academic books: fairly technical, thought-provoking, never shirking the hard questions, and yet admirably brief at 207 pages. One thing Hone does not do is introduce and explain the various techniques. He assumes that phrases such as isotope data, palynology, and finite element analysis mean something to you and do not require more than a brief definition. If you find your eyes glazing over at these terms, maybe start with Benton’s book. For everyone else, however, Uncovering Dinosaur Behavior is a superb book that should be your go-to reference for a thoughtful appraisal of what we know about dinosaur behaviour.

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

Uncovering Dinosaur Behavior

Other recommended books mentioned in this review:

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8-minute read
keywords: anatomy, biomechanics, paleontology

Having just reviewed a general illustrated introduction to dinosaur behaviour, I indicated wanting to go deeper. An Illustrated Guide to Dinosaur Feeding Biology provides in spades. This technical book gives a detailed and substantial taxon-by-taxon overview of what dinosaur skulls, jaws, and teeth reveal about what, but especially how dinosaurs ate. This is a welcome survey of an otherwise scattered literature that will be invaluable for specialists.

An Illustrated Guide to Dinosaur Feeding Biology, written by Ali Nabavizadeh & David B. Weishampel, published by Johns Hopkins University Press in June 2023 (hardback, 353 pages)

Ali Nabavizadeh is an assistant professor of anatomy who has spent the last 15-odd years working on cranial musculature and feeding mechanisms in dinosaurs, elephants, and dicynodonts. David B. Weishampel is a professor emeritus in anatomy and palaeobiology and is Nabavizadeh’s graduate advisor. With a research career of over 45 years, you will undoubtedly recognize him as e.g. co-author on four editions of the textbook Dinosaurs: A Concise Natural History and co-editor on two editions of The Dinosauria. In other words, you are in good, expert hands.

An Illustrated Guide to Dinosaur Feeding Biology breaks down into roughly two parts: a background section and a taxonomic overview. Three background chapters form the aperitif. First is a guide to some of the major historical studies and milestones; the question of what dinosaurs ate has been part and parcel of palaeontology since the start. Also covered are the vegetation of the Mesozoic and trace fossil evidence of diets such as gastroliths and coprolites. Second is the basic biology of bones, teeth, and muscles, in particular their functional morphology, which studies what all this anatomy actually does in a living organism. Since dinosaurs are, well, dead, an awful lot of this relies on a solid understanding of, and comparison to, animals alive today, preferably descendants (birds), close relatives (crocodilians and lizards), and functional analogues (large herbivores). Functional morphology also involves techniques old and modern, whether histology of fossil bones, studies of dental microwear, or biomechanical analysis using techniques borrowed from engineering such as finite element analysis (FEA) or multibody dynamics analysis (MDA). Though you would have to look elsewhere for an introduction to biomechanics, my impression is that familiarity with this is not a strict requirement. The third thing you will need is an understanding of anatomy, especially of the skull. This chapter provides names and terminology of cranial bones, muscles, and soft tissues; a primer on postcranial anatomy (i.e. the rest of the body); and of course the all-important names for directions and orientations when navigating your way around this anatomy. You will want to bookmark page 32 if you struggle to tell your rostral from your caudal, and your labial from your lingual.

“with all due respect to carnivorous dinosaurs, if this book taught me one thing about jaw mechanics it is that herbivorous dinosaurs is where it is at.”

After this introduction, the main course consists of ten chapters that give a taxonomic overview. As you may be aware, the traditional division between Saurischia and Ornithischia received a shake-up in 2017 with a paper by Baron and colleagues. In very brief they proposed that, rather than
Theropoda + Sauropodomorpha = Saurischia,
Theropoda + Ornithischia = Ornithoscelida.
Though Nabavizadeh & Weishampel embrace the traditional division, they opt for a halfway-house solution and drill down the family trees of Theropoda, Sauropodomorpha, and Ornithischia separately. Each chapter opens with a family tree and then per subclade discusses available studies and findings on skulls, teeth, the likely feeding mechanism (i.e. how jaws chewed), inferred musculature, biomechanics (e.g. strains, stresses, and bite forces), the role of postcranial anatomy such as limbs and necks in feeding, and any direct evidence (e.g. bite marks) and trace fossil evidence. This is illustrated with drawings of reconstructed heads with overlays of jaw musculature and hypothesized jaw motions, as well as annotated photographs of skulls pointing out relevant and noteworthy features.

What does this survey reveal? When dinosaur feeding biology does make the news, attention usually focuses on carnivorous theropods: apparently, we are all dying to know how hard T. rex‘s chompers chomped. The answer, as discussed here, is bone-pulverizingly hard. More interesting I found, for instance, the idea that Allosauroids, rather than biting down hard, used their heads like a hatchet. The combination of relatively weak jaw muscles and strong neck muscles has led some authors to hypothesize that they used a puncture-pull mechanism of high-speed strikes followed by pulling back of the head to tear chunks of flesh off the prey. Or what to make of Alvarezsauridae who had a small skull with tiny teeth and highly reduced forelimbs with a single enlarged claw each? We do not really know what they ate. And remember the famous sickle-claw of Deinonychus? Rather than disembowelling prey, it was more likely used to grip and immobilize them, not unlike birds of prey do today.

Now, with all due respect to carnivorous dinosaurs, if this book taught me one thing about jaw mechanics it is that herbivorous dinosaurs is where it is at. For example, next to orthal (up-and-down) motion of the jaws, several groups add propalinal (back-and-forth) motion and even long-axis hemi-mandibular rotation: imagine that each half of your lower jaw could roll sideways, pointing your teeth inwards towards your tongue. Sauropods had unique skulls amongst dinosaurs, with adductor chambers for some of the major jaw muscles positioned below rather than behind the orbits holding the eyes. It is relatively well known that hadrosaurids and ceratopsids had dental batteries, the lower jaw containing hundreds of teeth packed in rows of stacked tooth columns. More interesting is how these teeth consisted of not the usual two, but five or six tissue types of different hardness, wearing down in a complex fashion while eating tough and fibrous vegetation.

“Equally interesting are the gaps in our knowledge […] we know almost nothing about dinosaur tongues.”

Equally interesting are the gaps in our knowledge. Except for ankylosaurs, for most groups we have little to no fossilized hyobranchial elements, the bones to which the tongue would have attached in life, meaning we know almost nothing about dinosaur tongues. What happened to diets as dinosaurs grew up? There are only a few taxa for which we have enough baby, juvenile, and adult fossils to construct ontogenetic series, but the results are intriguing. Limusaurus, part of the early theropod subclade Noasauridae, had small teeth as juveniles but lost them as adults, suggesting a shift from omnivory to herbivory. Similarly, the juveniles and adults of both diplodocoids and hadrosaurids differed in cranial and dental morphology, suggesting they fed on different types of plants as they grew up (so-called niche partitioning).

Despite its advanced level and technical detail, this book is accessibly written. You get into the swing of the terminology soon enough and each chapter writes out abbreviations at first use, meaning that, after the background chapters, you can read the book out of order. Cladograms in each chapter are useful in helping you understand sometimes unwieldy descriptors such as “non-ceratopsoid ceratopsians”. I have two minor nitpicks. First, I would not have minded if the authors had organized information for each subclade with further subheadings. The information is all there, and each chapter discusses skulls, teeth, biomechanics, etc. in the same order, but for intensively studied groups, this results in pages-long uninterrupted blocks of text. Some extra signposting would have helped navigate and later relocate information. Second, the drawings are very useful, though stylistically it feels Nabavizadeh is overusing the smudge/airbrush tool to smooth out textures. I actually prefer the few drawings where he has not done so, such as the comparison of Centrosaurus and Chasmosaurus on page 281. The use of white gradients around the arrows labelling photos and drawings is a lifesaver, however; it would have been impossible to tell what they are pointing to otherwise.

So, who is this book for? Whereas the previously reviewed Dinosaur Behavior was probably too superficial for all but palaeontology novices, this book is positioned at the other end of the spectrum, being only one step removed from the proverbial coalface of the primary technical literature. For palaeontologists and especially those working on dinosaur feeding biology, or facets thereof, this will be a very welcome overview, with the 38 pages of references being a goldmine of curated literature. For students entering this field, a book like this is a godsend. For the wider audience of dinosaur enthusiasts and palaeontology fanatics, this book should be, as mentioned earlier, accessible enough. If you take an undergraduate textbook such as Fastovsky & Weishampel’s Dinosaurs as your starting point, An Illustrated Guide to Dinosaur Feeding Biology would be the logical and manageable follow-up to deepen your knowledge on the topic. I, for one, cannot get enough of these kinds of advanced-level syntheses and enjoyed ploughing through this book.

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

An Illustrated Guide to Dinosaur Feeding Biology

Other recommended books mentioned in this review:

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6-minute read
keywords: paleontology

Reconstructing how dinosaurs behaved from just their fossilised bones might seem like science fiction but is very much science fact. Join me for a double review of two recent illustrated books. I will next review An Illustrated Guide to Dinosaur Feeding Biology but first up is Dinosaur Behavior: An Illustrated Guide. Here, veteran palaeontology professor Michael J. Benton joins forces with palaeoartist Bob Nicholls to do what it says on the tin: write a richly illustrated introductory book on dinosaur behaviour that is well-suited for novices.

Dinosaur Behavior: An Illustrated Guide, written by Michael J. Benton, illustrated by Bob Nicholls, published by Princeton University Press in October 2023 (hardback, 224 pages)

Dinosaur behaviour has come up previously on this blog. Locked in Time, also illustrated by Bob Nicholls, featured 50 vignettes of famous fossils, while Dinosaurs Without Bones was a chunky pop-science book. In Dinosaur Behavior, Benton takes the reader through five main topics: physiology (which sets the pace for everything else), locomotion, senses and intelligence, feeding, and social behaviour (which includes courtship, reproduction, parental care, and communication). One or several “forensics” boxes in each chapter introduce the basic gist of certain methods.

Reading through this book, it becomes abundantly clear that our understanding of dinosaur behaviour relies on two approaches. Though Benton does not mention it as explicitly as in his previous book The Dinosaurs Rediscovered, the first of these is new high-tech toys and tools. Examples include computed tomography (CT) scanners normally used in hospitals to make detailed X-ray scans of fossilised brains (so-called endocasts) and so determine brain anatomy, or finite element analysis normally used in engineering to model forces and stresses on jaws and teeth and so determine e.g. bite force. The second approach is “old-fashioned” comparative anatomy and ethology: it pays to have a good knowledge of natural history when you are a palaeontologist. One example is the histological study of fossil dinosaur bones. Cutting thin bone sections and examining these under a microscope shows that some dinosaurs closely resemble mammals and birds, supporting the idea that smaller species were endotherms (“warm-blooded”, i.e. generating their own body heat). Or take the microscopic study of melanosomes (pigment-containing organelles) in fossil feathers to determine colour in life. A final example is the comparison of footprints made by modern running birds with fossil tracks to determine things such as gait and running speed.

“it becomes abundantly clear that our understanding of dinosaur behaviour relies on two approaches […] new high-tech toys and tools [and] “old-fashioned” comparative anatomy and ethology.”

If you are well-versed in (popular) palaeontology, much of what is presented here will be familiar. Even so, I picked up interesting titbits. One example is a recent study of Psittacosaurus that describes a cloaca, the multipurpose orifice also seen in birds where the digestive, urinary, and reproductive tracts all open to the outside world. This suggests that dinosaur sex for at least some species was a matter of the appropriately named cloacal kiss rather than the brandishing of reptilian genitals. Other insights fell into the embarrassing “I should have known this” category. We tend to think of walking on two legs as something advanced because our mammalian ancestors walked on all fours, but for dinosaurs, it was the reverse; they started out bipedal and quadrupedality only evolved later in e.g. the large sauropods. Particularly interesting is the study by Kat Schroeder and colleagues who looked at fossil communities of theropods and noticed a so-called carnivore gap: there is a lack of medium-sized ones in the fossil record, even though there are medium-sized herbivores. One explanation could be that dinosaur eggs had an upper size limit, meaning that young carnivores hatched small and had an awful lot of growing to do. As they did, “they passed through a whole range of feeding modes, each step along the way acting like a different species” (p. 137), effectively plugging the ecological niche of medium-sized carnivores.

Despite the broad range of topics, there are some curious omissions. The chapter on feeding e.g. discusses jaws, teeth, and the use of isotopes to determine diet, but not microwear analysis of teeth. What I found most surprising is that Benton does not introduce the concept of trace fossils or ichnology, their study. Yet, examples such as trackways (some possibly showing long-distance migrations), coprolites (fossil poop), and nests are all discussed here. Another surprising omission is that the two-page bibliography does not include most studies mentioned in the text, even though it references other technical articles.

“dinosaur sex for at least some species was a matter of the appropriately named cloacal kiss rather than the brandishing of reptilian genitals.”

Dinosaur Behavior is mostly very suitable for readers with little to no background in palaeontology. Benton explains even basic terminology (physiology, cannibalism) as he goes, though there is the occasional curveball. One example is the morphospace diagram showing a principal component analysis on page 131, which, I hope those with a background in statistics will agree, is a rather abstract way of visualizing data that requires a bit more explanation than is given here. Though the book is published by Princeton University Press, it has been produced by UniPress Books who, as I explained in a footnote to another review, can be considered the spiritual successor to popular science publisher Ivy Press. What this means is that information is accessibly presented in bite-sized sections on one or several page spreads, with long sections further divided using subheadings. The downside is that this restricts how thoroughly topics can be explored. Leafing through e.g. Naish & Barrett’s Dinosaurs: How They Lived and Evolved shows more nuance in its chapter on behaviour.

Finally, I have to mention the excellent colour and black-and-white artwork by Bob Nicholls that livens up the text. I loved the drawing of courtship in Confusiusornis on pages 168–169. Despite the overlap in topic, this is all-new artwork compared to Locked in Time. Other diagrams have all been carefully designed or redrawn, using colours where appropriate. The only design element that did not work for me was the choice of sans-serif font which made e.g. the letters a and o hard to tell apart.

Overall, this is a handsomely illustrated book that offers an accessible introduction suitable for novices and possibly even curious high-school pupils. Since it is December, I will add the words “gift suggestion” to that. Admittedly, serious palaeontology buffs might find the contents here somewhat superficial. So what if you wanted to go deeper on one of these topics, what would that look like? I will next turn to An Illustrated Guide to Dinosaur Feeding Biology to find out. [Edit: As of November 2024, the logical follow-up I would recommend is David Hone’s Uncovering Dinosaur Behavior.]

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

Dinosaur Behavior

Other recommended books mentioned in this review:

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Given that we are nothing but mammals, it is perhaps understandable that humans are rather mammal-centric, something that conservation organisations capitalise on. But where palaeontology is concerned, dinosaurs get all the love. And that does early mammals little justice says Scottish palaeontologist and Palaeocast co-host Elsa Panciroli. Far from mere bit players cowering in the shadows of these “terrible lizards”, mammals have a long and rich evolutionary history that predates the dinosaurs but is poorly known outside of specialist circles. Panciroli’s debut changes all that and does so in a most readable and immersive fashion.

Beasts Before Us: The Untold Story of Mammal Origins and Evolution, written by Elsa Panciroli, published in Europe by Bloomsbury Publishing in June 2021 (hardback, 320 pages)

To pick up the tale of mammal evolution, Panciroli takes you all the way back to the Carboniferous (roughly 360–300 million years ago) when higher oxygen levels supported a land of giants. It was here that the first fish made landfall and tetrapods evolved. To get from this distant ancestor to modern mammals, you have to follow the story through groups whose names are likely unfamiliar. To help you visualise these, stylish illustrations from April Neander open each chapter, while the endpapers* provide a helpful family tree drawn by Marc Dando. These do not list all mentioned groups but do present the big picture and I found myself referring to them frequently.

Thus we get to meet the synapsids, one of which you will know: the sail-backed, no-it-is-not-a-dinosaur Dimetrodon. Synapsids included the pelycosaurs (also not dinosaurs), which gave rise to the therapsids: carnivores with more powerful jaws and a stronger bite. Some of these, including the gorgonopsians, pioneered sabre-teeth, proving later groups to be mere copy-cats. Convergent evolution is, quite literally, a recurrent theme that Panciroli mentions whenever she can get away with it. Various therapsids were also the first groups to evolve endothermy or warm-bloodedness, though “like so many of the features associated with mammals [it] emerged scattershot. It wasn’t switched on like a lightbulb, lighting up all therapsids at once” (p. 120).

As the end-Permian mass extinction wiped the slate clean, the age of reptiles had begun. But some of our mammal ancestors survived. Rising like a phoenix from the ashes were, amongst others, the dicynodonts, who would have looked you in the eye from behind tusks and a turtle-like beak. One particularly successful group, possibly because it dug burrows, was Lystrosaurus, a genus that in the early Triassic made up 90% of all vertebrates. A related group, the cynodonts, is largely responsible for the misconception that our ancestors were insignificant during the reign of the dinosaurs, as they evolved to be smaller. But this was a feature, not a bug: “With no space among the giants, they took a different route: they perfected being tiny” (p. 163). They exploited the safety of the night, became nocturnal, and developed sensitive eyes. They also lost some ribs and developed a waist, allowing for more flexibility in their locomotion—early synapsids had ribs all the way down.

“[One] group, the cynodonts, is largely responsible for the misconception that our ancestors were insignificant during the reign of the dinosaurs, as they evolved to be smaller. But this was a feature, not a bug”

The Jurassic saw groups such as tritylodontids, docodontans, and multituberculates flourish. As their names imply, these groups experimented with tooth morphology, which later became important diagnostic fossil characters. None of them left living descendants. Instead, it was the therians who were our direct ancestors, but they did not diversify until after the K–Pg boundary. Interestingly, Panciroli suggests** that it was not the dinosaurs that kept the therians in check, but competition from all the other Jurassic mammal groups. This more recent history of the adaptive radiation into modern marsupials and placental mammals is well known, so she purposefully ends the book where most others start the story of mammal evolution .

This brief exercise in name-dropping provides only a snapshot of what Panciroli discusses, and she does a far better job of it. She weaves in the history of fossil discovery and her own work at dig sites in South Africa and Scotland, or labwork at the European Synchrotron Radiation Facility in France. Next to telling the story of mammal evolution, Panciroli also takes on the task of disarming and deconstructing a large amount of cultural and linguistic baggage, with two issues standing out.

First, as part of a younger generation of scientists, Panciroli is keen to decolonise her discipline. This means acknowledging that the scientific collections on which she herself works are the spoils of empire. Our museums are filled with colonialist plunder. Especially in the first chapter, where she gives a potted history of geology and biology, she repeatedly points to the imperialist framework in which these disciplines were born and how that has shaped conventions and biases to this day. Celebrated figureheads such as Buckland, Darwin, Lyell, Cuvier, Hutton, Lamarck, Owen etc. simultaneously held ideas now considered unsavoury, and they rarely credited Indigenous knowledge or help in the acquisition of fossils. Furthermore, as a woman, she has a few things to say about diversity. Like many academic disciplines, palaeontology remains largely populated by white, Western men, and it has been hard to shake off the image of the “stereotypical male adventurer” and his “macho plundering of the past” (p. 249). Fortunately, the contributions of women are increasingly being acknowledged, and Panciroli here celebrates Polish Mesozoic mammal researcher Zofia Kielan-Jaworowska who was the first woman to lead fossil collection expeditions in Mongolia.

“[…] the long history of evolutionary theory means that outdated modes of thinking continue to permeate our language. […] Panciroli similarly uses every opportunity to remind you that evolution is not goal-directed”

Second, the long history of evolutionary theory means that outdated modes of thinking continue to permeate our language. She shudders at the term “mammal-like reptiles” still used to describe the synapsids: “This first amniote tetrapod was neither mammal nor reptile—neither of those groups had evolved yet” (p. 61). We did not evolve from reptiles, nor are they more primitive compared to us. Panciroli similarly uses every opportunity to remind you that evolution is not goal-directed: “It is random, the route forged by happenstance” (p. 57). It has proven hard to let go of the Scala Naturae, the idea of a linear series of improvements, “like an assembly-line through time” (p. 120) leading ultimately to the perfect organism: us.

This neatly leads to my last observation: Panciroli’s writing is sublime. Her prose is concise without being stunted, her visual metaphors rich without being flowery. Of the late Triassic mammals she writes: “These tiny ancestors were living microchips. They were night-vision goggles. They were fuzzy little ninjas, wielding shuriken teeth to reap their insect prey in silence and stealth” (p. 171). On the break-up of Pangaea: “After their epic 250 million-year snuggle, the continents of Earth were parting ways […] By the end of the Jurassic, the whole world was unzipping itself, with new seas and oceans splashing into the gaps” (p. 203). On the K–Pg event: “The universe drew an iridium line under things. From here on, life would be different” (p. 274). And her description of the tritylodontid herbivore niche is just beautiful: “All of the non-mammalian cynodonts had turned to dust, except for the tritylodontids […]. Natural selection had moulded them into premier leaf-grinding machines. Of course there had been synapsid herbivores before […] but those bulky predecessors were gone. In the world of crocs and dinosaurs, mammals had microscoped themselves into the understorey, and the tritylodontids were left to eat the scenery” (p. 237).

Beyond a few academic textbooks and technical monographs, the deep evolutionary history of mammals has remained largely hidden in the academic literature. Beasts Before Us unleashes their story most spectacularly and engagingly. This beautifully written debut marks Panciroli as a noteworthy new popular science author. May this be the first of many books! You might also want to check out my Q&A with Panciroli published over at the NHBS Conservation Hub.

* Illustrated endpapers are one of my favourite features in a book, and one that, I think, too few publishers and authors use.

** The paper arguing this, still in press when she wrote this book, has just been published in Current Biology.

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

Beasts Before Us

Other recommended books mentioned in this review:

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Say “dinosaurs”, and most people imagine fossilised bones and spectacular museum displays. But body fossils are not the only remains we have with which to reconstruct dinosaur lives. Nor, and this might sound controversial, are they the most important. Or so argues palaeontologist, geologist, and ichnologist Anthony J. Martin. Ichnology is the study of animal traces, whether modern or fossilised. Most traces are ephemeral and disappear within hours or days, but occasionally some are buried and end up in the fossil record. With tongue firmly planted in cheek, and with more puns than you can shake a T. rex thigh bone at, Martin forays into the rich dinosaur trace fossil record: from footprints, burrows, and nests, to teeth marks and fossil faeces. For all the jokes, and despite having been published in 2014, he raises some really interesting points.

Dinosaurs Without Bones: Dinosaur Lives Revealed by Their Trace Fossils, written by Anthony J. Martin, published by Pegasus Books in April 2015 (paperback, 484 pages)

You might indeed ask, why review this book now? Way back in 2018 I reviewed Martin’s 2017 book The Evolution Underground on the evolutionary history of burrowing behaviour and was suitably impressed. I vowed to search out his previous book, though I did not intend to wait this long. Having just reviewed Lomax’s book Locked in Time, now was the right time to make up for that.

Animals of all sorts leave behind traces wherever they go and dinosaurs were no exception. Footprints are probably the first thing to come to mind and a logical place to start. From the US, to Europe, to South America, they have been found on every continent except Antarctica*. Martin discusses how the number of toes and their orientation can reveal what group of dinosaur left the footprint and how their size can be used to estimate its maker’s size. Where multiple footprints form a trackway, their distance can reveal gait and velocity, or whether dinosaurs moved alone or in (family) groups. And with technological advances, we can extract more information from footprints than ever before.

One interesting thing Martin reveals here that I was not aware of, is that most fossil tracks are probably undertracks. That is, the subsurface deformation of the substrate caused by the pressure of the foot. Most tracks likely soon weathered beyond recognition, so unless you find clear skin impressions, the prudent assumption is that you are dealing with undertracks. As he points out: “The decided preservational advantage of this phenomenon is that such tracks were already buried, protecting them from destruction” (p. 33).

“One interesting thing Martin reveals here […] is that most fossil tracks are probably undertracks. That is, the subsurface deformation of the substrate caused by the pressure of the foot […]”

But feet can do much more than just walking and Martin examines trace fossil evidence of dinosaur nests and fossil burrows. Beyond traces made by feet, bones can record tooth marks, though care is needed to distinguish attacks on living animals from post-mortem scavenging. In turn, food leaves tell-tale traces of microwear on a tooth’s surface. More exotic—and controversial—are gastroliths or stomach stones that can act as digestive aids, though likely not all were swallowed on purpose. And then there is that which comes out at the other end. You might have heard of coprolites (fossil dung), and Lomax introduced me to urolites (fossil traces of urination). But what of enterolites (fossil stomach contents) and cololites (fossil intestinal contents)? Or, my favourite, regurgitalites—which is what you think it is.

For some behaviours we do not have clear evidence, while others are highly unlikely to leave traces in the fossil record. But this does segue nicely into one of the most important themes of this book: search image. At several points, Martin encourages readers and researchers alike to ask themselves: what would the traces left by certain behaviours look like? Take sauropod footprints. Given their size you might think they are hard to miss and yet: “In the early days of dinosaur tracking probably more than one paleontologist or geologist walked by their footprints without a second glance, thinking they were some sort of large erosion-caused features. Once these footprints were correlated with the sizes and shapes of sauropod feet […] sauropod tracks magically appeared in the search images of paleontologists worldwide” (p. 22). An important point of reference, and one that Martin profiled for his home turf of Georgia in his previous book, are the traces left by animals alive today, specifically birds. Because, as he reminds you towards the end of the book by shortly recapping the evolution of birds, technically speaking birds are living, flying, feathered dinosaurs.

“[…] one of the most important themes of this book [is] search image. At several points, Martin encourages readers and researchers alike to ask themselves: what would the traces left by certain behaviours look like?”

The other thing to note is Martin’s writing style. All of the above is served up with a healthy dollop of frequently irreverent humour. Some of it borders on dad-jokes though, so let me give you some tasters. He frequently lampoons his own profession: “[…] even dinosaur-track experts have doubts about the identity of some three-toed dinosaur tracks, especially if a rival dinosaur-track expert identified them” (p. 22), and regarding peer review “[…] the scientists who review journal articles are doing it as unpaid volunteers, finding time to perform this important duty in between all of their other tasks such as teaching, grading, research, walking the dog, or (most heinous of all) sleeping” (p. 76). The rear part of a dinosaur “[…] is properly called an ischial callosity, and not the more appealing term “dinosaur butt”” (p. 39). On front teeth: “If a theropod’s potential food item, such as a small ornithopod, was still alive and having issues with a proposal that it should devote its life to feeding a theropod, then the front teeth were the most persuasive tools used by that theropod” (p. 181). And on urolites: “Paleontologists who do such research could be assured of making a big splash with it, while also going against the flow of others’ prejudices. Afterwards, they will be flushed with success, and their colleagues pissed off” (p. 247). If the above made you laugh, you will have a blast with this book. I certainly did.

Dinosaurs Without Bones is great popular science: fascinating, thought-provoking, and told with verve and wit. This is an excellent companion book to Lomax’s Locked in Time and a very nice introduction to trace fossils and ichnology. My only regret is that I waited so long before finally reading it.

* That was true when this book was published in 2014. When I followed up on this, I found one news item claiming the 2016 find of a dinosaur footprint on Antarctica. However, when reading the actual 2019 paper in the open-access journal Polar Research, the authors are a bit more circumspect, attributing this footprint to “a primitive amniote, procolophonid or therapsid“.

Dinosaurs without Bones

Other recommended books mentioned in this review:

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Fossils can tell us what animals living in the distant past looked like. Over the centuries, palaeontologists have made incredible strides in reconstructing extinct life forms, helped along by cumulative experience, technological advances, and a steadily increasing body of rare but truly exceptionally preserved fossils. But reconstructing their behaviour—surely that is all just speculative? In Locked in Time, palaeontologist and science communicator Dean R. Lomax, with the able help of palaeoartist Bob Nicholls, presents fifty of the most exceptional fossils that preserve evidence of past behaviour: from pregnant plesiosaurs to a pterosaur pierced by a predatory fish. I was eagerly awaiting this book from the moment it was announced, but I was still caught off-guard by some of the astonishing fossil discoveries featured here.

Locked in Time: Animal Behavior Unearthed in 50 Extraordinary Fossils, written by Dean R. Lomax and illustrated by Robert Nicholls, published by Columbia University Press in May 2021 (hardback, 312 pages)

Locked in Time effectively consists of fifty vignettes organised around five themes. Perhaps surprisingly, this is not the first popular science book on behaviour revealed by the fossil record. Anthony J. Martin wrote Dinosaurs Without Bones in 2014, focusing on ichnology, the study of trace fossils such as fossil footprints, scratch marks, or nests. Lomax, however, casts his net far wider than just dinosaurs and has scoured the scientific literature for both trace and body fossils that reveal how these animals likely behaved in life. Some examples require careful inference, while others, cases that the pioneer Arthur Boucot called “frozen behaviour”, are blindingly obvious.

There are some truly astonishing fossils featured here. An ichthyosaur that died while giving birth proves beyond a doubt they were live-bearing. A pair of turtles was unfortunate enough to end up caught in the act of mating for eternity. There are well-known fossils such as the pregnant mother fish Materpiscis, the battle between a Protoceratops and a Velociraptor featured on the book’s cover, or the tall spiral structures once nicknamed Devil’s corkscrews by flummoxed fossil hunters that turned out to be burrows, some even containing fossilised beavers. There is violence: the skulls of two fighting male mammoths that died with tusks still interlocked; but also tranquillity: the fossil troodontid Mei long that was found in a posture reminiscent of modern-day birds resting or sleeping. There is the fossil that got Lomax started on this project: a metres-long trackway of a horseshoe crab scurrying over a lake bottom with the individual fossilised at the end of it! There is palaeopathology, parasites, and even fossil farts.

But make no mistake, Locked in Time is much more than a book of trivia and factoids. Palaeoethology, the study of behaviour of organisms in the fossil record, is a proper subdiscipline of palaeontology and has bearings on the study of palaeoecology. And for all the spectacular fossils and occasional puns, Lomax also subtly educates his reader on more serious topics. Three things struck me in particular.

“There is palaeopathology, parasites, and even fossil farts. But make no mistake, Locked in Time is much more than a book of trivia and factoids.”

First, as Lomax acknowledges, not all interpretations of behaviour are uncontested. Are the fossils of the primitive bird Confuciusornis sanctus that display exquisitely preserved ornamental feathers really males? Further research showed the fossils without these feathers to contain medullary bone, a temporary tissue associated exclusively with reproductively active females. The ornamented individuals showed no such evidence, strengthening the case for sexual dimorphism in this species. Or what of the 200-year-old claim that ichthyosaurs were cannibals? It took until the 1990s when further detailed studies of presumed stomach contents concluded that there were no signs of bite marks or etchings by stomach acids, strengthening the case that these were instead embryos. An important theme that Lomax highlights repeatedly is the utility of studying the behaviour of animals alive today. Although care is in order, comparisons with the behaviour of extant animals and the traces they leave can help demystify the behaviour of extinct animals.

Second, Lomax reveals the inner workings of palaeontology. It is not uncommon for fossils to linger for years or even decades after excavation pending the availability of funding and a skilled preparator. One specimen of the plesiosaur Polycotylus latipinnus was dug up in 1987 but not prepared until 2011, finally revealing its pregnancy. Sometimes technological advances breathe new life into old fossils, such as the burrow containing the therapsid Thrinaxodon liorhinus that was discovered in 1975. Not until 2013, when it was examined with powerful x-rays at a synchrotron facility, did the partially prepared fossil reveal a thus-far hidden injured amphibian that had crawled into the burrow and nestled itself against the likely dormant Thrinaxodon. In other cases, palaeontologists have to beware of frauds, as traders occasionally doctor fossils to make them fetch a higher price on the marketplace—some stories could just be too good to be true.

Third, Lomax proves himself to be a gentle educator. He will immediately explain jargon (e.g. Lagerstätten, ecdysis, or anamorphosis) and only introduce it where appropriate. And though this is popular science, Lomax is keen to bust myths. No, the large shark Megalodon is no longer alive, and there is zero evidence for either Dilophosaurus or other dinosaurs being capable of spitting acid, no matter what Jurassic Park tried to tell you. He beautifully channels deep time when writing “Before dinosaurs even appeared, trilobites were already fossils under their feet” (p. 110), and explains why trace fossils are much more common than body fossils: “Over its lifetime, an animal might leave behind countless footprints […] but only one skeleton” (p. 105).

“An important theme that Lomax highlights repeatedly is the utility of studying the behaviour of animals alive today. Although care is in order, comparisons […] can help demystify the behaviour of extinct animals.”

Finally, seeing is believing, and Locked in Time is richly illustrated. Most vignettes include photos and schematic drawings of the fossils, and my jaw dropped on numerous occasions. Given that disarticulated and fragmentary fossils are the norm, the selection that Lomax has curated here is truly breathtaking. Furthermore, all vignettes include a single or double-page spread with palaeoart from Bob Nicholls, tastefully reproduced in grayscale. He was featured in Dinosaur Art and wrote the introduction to Dinosaur Art II where he discussed his Psitaccosaurus reconstruction mentioned here on p. 75. Nicholl’s artwork is heavily informed by science and adds much flavour to this book.

In an interview I did with Lomax, published at the NHBS Conservation Hub, he mentioned having made an initial selection of 100 fossils, so many fascinating examples did not make the cut. Other interesting studies were unfortunately published too recently to be considered for inclusion, such as the 2021 Caneer et al. paper discussing possible tracks made by a Tyrannosaurid rising from a prone position, or the 2021 Lockley et al. paper on the sand-swimming trace fossils left by a Pleistocene golden mole.

Locked in Time is an outstanding and highly original piece of popular science that overflows with Lomax’s enthusiasm and passion for his topic. Even if your shelves are already heaving with palaeontology books, make space for one more. Believe me, you have not seen a book like this before.

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

Locked in Time

Other recommended books mentioned in this review:

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The reintroduction of wolves to Yellowstone National Park is one of the best-known examples of wildlife conservation. To celebrate its 25th anniversary and summarise the many lessons learned, Yellowstone Wolf Project leaders Douglas W. Smith and Daniel R. Stahler, together with wildlife ecologist Daniel R. MacNulty, bring together research from over 70 colleagues in this large, edited collection. The combination of academic content, excellent photography, guest essays, and an online bonus documentary with interviews make this the go-to reference work for anyone wanting to go beyond the headlines on this reintroduction project.

Yellowstone Wolves: Science and Discovery in the World’s First National Park, edited by Douglas W. Smith, Daniel R. Stahler, and Daniel R. MacNulty, published by the University of Chicago Press in December 2020 (hardback, 339 pages)

The first thing that struck me about Yellowstone Wolves is how well-organised the book is. Six parts contain nineteen chapters, none going beyond twenty pages, and most include a clearly signposted conclusion. To give equal airtime to so many different studies and opinions is remarkable—the six years the editors spent on this book have borne fruit. The second thing is how readable the book is. To do justice to the subtleties and complexities of real-world ecosystems means digging into scientific research. Thus, it discusses methodologies and research results and provides graphs galore, but without bogging the reader down with excessive jargon or complex statistics. Only occasionally, when the discussion turned to species interactions or ecosystem ecology, did I feel that I was reading an academic paper.

So, what have we learned from 25 years of having wolves back in Yellowstone? This book covers a wide range of topics, more than I can hope to discuss here. Sensibly, it opens with a short history of the park, wolf extermination, and the reintroduction—a dramatic story complete with last-minute lawsuits that almost scuppered the whole operation.

“The first thing that struck me about Yellowstone Wolves is how well-organised the book is. […] To give equal airtime to so many different studies and opinions is remarkable”

After some basic wolf biology, the bulk of the book discusses long-term research. This covers pathogens and parasites, the genetic studies that inform wolf pedigrees and explain why you see both black and grey wolves in the park, and, notably, the different aspects of wolf packs. How they form, how long they last, how they defend territories and compete with one another, and how they change over time. This introduces some of the legendary wolves from Rick McIntyre‘s Alpha Wolves of Yellowstone series, or the very popular female O-Six, but also reveals the value of older wolves to their pack, or the surprisingly high mortality due to intraspecific (i.e. wolf-wolf) conflict when wolves are not constantly hunted by humans.

My impression, however, is that the seven chapters across parts 4 and 5 will be the most relevant to many readers. Why? First, because the chapters on community ecology (particularly wolf-prey interactions) touch both on the concerns of the hunters and ranchers who opposed wolf reintroduction, and on the challenges faced by generations of park managers. Second, because the topic of ecosystem ecology (the effects of wolves on ecosystems) catapulted the park to internet fame.

We are going to need some history here.

Woven throughout this book is the story of how predator removal at the beginning of the 20th century saw elk populations boom, leading to concerns of too many elk overgrazing and trampling the park and surrounding farmland. From 1920 to 1968 park management and hunters culled and relocated tens of thousands of elk, leading to concerns of too few elk and, from 1969 onwards, new policies that let nature take its course. Predictably, without predators, there was a new elk boom. This is the context in which wolf reintroduction was finally put on the table.

“Of course, wolves eat elk, but the devil is in the details […] these chapters seek to correct misconceptions [as] wolves are not the ungulate killing machines some imagine”

Elk numbers have since declined again, causing—you cannot please everyone—renewed consternation. This time, though, wolves get the blame. Of course, wolves eat elk, but the devil is in the details: “what is in doubt is the size and timing of [their] contribution” (p. 187). So, these chapters seek to correct misconceptions. Though wolves are formidable pack hunters capable of taking down large prey, failure is frequent and the risk of injury high. Lacking the powerful bite and retractable claws of big cats or the muscular forelimbs of bears, wolves are not the ungulate killing machines some imagine, instead preying on young, old, and sick elk, or scavenging e.g. bison carcasses. Furthermore, elk decline started months before the wolves returned to Yellowstone in 1995. In subsequent years other predators such as cougars, bears, and coyotes also flourished, while hunters continued to shoot substantial numbers of elk just outside the park. Guest contributors weigh in here with lessons learned from other long-term wolf studies in national parks such as the island of Isle Royale, Banff, and Denali.

The other controversial topic tackled is ecosystem effects: the idea that the impact of predators on prey affects the prey’s food base, rippling down the food web and influencing a whole ecosystem. Now, such trophic cascades do occur in nature, but in Yellowstone’s case, the narrative has been hijacked by that one viral video clip, How Wolves Change Rivers. It presents a straightforward story of wolves killing elk, which reduced elk overgrazing of trees, in turn stabilising river banks and leading to the return of numerous animals. Broken ecosystem? Just add Wolves! Obviously, I am being facetious. In her contribution to Effective Conservation Science, Emma Marris examined the clip, the accusations of oversimplification, and the power of a good story. Ben Goldfarb, in his book Eager, noted that it downplays the effect of beaver reintroductions.

“the topic of ecosystem ecology […] catapulted the park to internet fame […] trophic cascades do occur in nature, but in Yellowstone’s case, the narrative has been hijacked by that one viral video clip”

Given this background, I was very curious to see how this book dealt with the matter. In one word: circumspect. The clip is only hinted at: “Some videos on the topic have garnered online audiences of millions. Although scientists have discredited some of these works as romantically simplistic […]” (p. 257). One chapter has a research group present the argument in favour of trophic cascades. They admit that indirect effects on vegetation have not been observed everywhere in the park where wolves now roam and add that players such as beavers, bison, wildfire, and disease complicate the picture. The next chapter has another research group consider more complex networks of interactions between wolves, other predators such as bears and cougars, scavengers, and herbivore prey. They open by writing that: “the preceding chapter considered […] processes in a single oversimplified food chain (i.e. wolves-elk-aspen/willow) in Yellowstone. Here, we discuss a broader set of food web relations that are too often ignored in the push to explain the links between wolves, elk, and vegetation” (p. 223). And so the discussion rumbles on.

The book ends with very relevant chapters on park management that explain the rationale behind visitor rules, celebrate dedicated wolf watchers, and hash out a framework for the perenially controversial topic of transboundary wolf management. That last one, in layman’s terms, gives recommendations for wildlife agencies on dealing with predators that cross the borders we draw on maps and come into conflict with stakeholders such as ranchers or hunters living near national parks.

As noted elsewhere, Yellowstone’s wildlife is subject to continuous change. By reintroducing wolves, scientists have had the unique opportunity to study the complexities of living, breathing ecosystems. Written by the very people who spent decades in the field doing the research, Yellowstone Wolves is a formidable achievement that presents a wide range of scientific topics in a well-organised, readable, and beautifully illustrated book.

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

Yellowstone Wolves

Other recommended books mentioned in this review:

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When I recently reviewed The Real Planet of the Apes, I casually wrote how that book dealt with the evolution of Old Work monkeys and apes, ignoring New World monkeys which went off on their own evolutionary experiment in South America. But that did leave me wondering. Those New World monkeys, what did they get up to then? Here, primatologist Alfred L. Rosenberger provides a comprehensive and incredibly accessible book that showed these monkeys to be far more fascinating than I imagined.

New World Monkeys: The Evolutionary Odyssey, written by Alfred L. Rosenberger, published by Princeton University Press in September 2020 (hardback, 350 pages)

Most people are probably not very familiar with these monkeys. Technically known as platyrrhines, they are predominantly arboreal (i.e. living in trees), small to medium-sized primates. You might know the insanely loud howler monkeys from nature documentaries. Perhaps you have heard of capuchin monkeys or spider monkeys. But you could be forgiven for not having heard of marmosets and tamarins, or the even more obscurely named titis, sakis, and uacaris. A total of 16 genera are recognized, but outside of the scientific literature and abovementioned technical books, these monkeys are not all that well known. And that is a shame as, from an evolutionary perspective, this is a unique group.

Now, before Rosenberger gets to this, it helps to better know these monkeys. Accompanied by many excellent illustrations and photos, the first half of New World Monkeys is dedicated to their ecology, behaviour, and morphology. Topics covered include their diet and dentition; locomotion and the anatomy of hands, feet, and prehensile tails; but also brain size and shape; and their social organization and ways of communicating via sight, sound, and smell.

The platyrrhines are a diverse bunch with some remarkable specialisations. In the family Cebidae we find the smallest members, some of whom, the Marmosets and Pygmy Marmosets, have teeth specialized for gouging the bark of gum trees and feeding on the gum that is released in response. In the family Pitheciidae we find the only nocturnal member, the Owl Monkeys, which have concomitant morphological adaptations such as enlarged eyes. In both this and the closely related Titi Monkeys, individuals have the adorable habit of twining their tails when e.g. socializing or sleeping. The family Atelidae is home to species with exceptionally prehensile tails whose underside ends in a pad with a fingertip-like surface. The Muriquis and the aptly-named Spider Monkeys use them as a fifth limb in locomotion, as demonstrated by a striking photo of a Black-faced Spider Monkey on plate 13. Here we also find the well-known Howler Monkeys, whose skull is heavily modified to support the exceptionally loud vocal organs in their throat and neck.

“[…] the whole radiation has been remarkably stable for at least 20 million years. Today’s New World monkeys are virtually unchanged from their ancestors […] This stands in sharp contrast to the evolutionary history of Old World monkeys […]”

Despite these differences, platyrrhines are closely related and form what is called an adaptive radiation. Just like the textbook example of Darwin’s finches, many members have evolved unique adaptations and ways of living to minimise competition and maximise resource partitioning. Two ideas feature prominently in this book to explain how platyrrhines have evolved and what makes this adaptive radiation both so diverse and so interesting.

One idea is what Rosenberger calls the Ecophylogenetics Hypothesis. If I have understood him correctly, this combines information on a species’s ecology and phylogeny, its evolutionary relationships. It can offer hypotheses on how ecological interactions have evolved, but it also recognizes that ecological adaptations are shaped and constrained by evolutionary relatedness. For the platyrrhines, taxonomically related members are also ecologically similar. To quote Rosenberger: “[…] phylogenetic relatedness literally breeds resemblance in form, ecology, and behavior” (p. 96) and “Each of the major taxonomic groups that we define phylogenetically is also an ecological unit […]” (p. 97).

The other idea that makes the platyrrhines so interesting is dubbed the Long-Lineage Hypothesis. An extensive chapter on the fossil record documents how the whole radiation has been remarkably stable for at least 20 million years. Today’s New World monkeys are virtually unchanged from their ancestors, living the same lifestyles and occupying the same ecological niches. Some fossils have even been classified in the same genus as their living counterparts. This stands in sharp contrast to the evolutionary history of Old World monkeys where there has been a constant churn, whole groups of primates evolving and going extinct with time.

“Without ever losing academic rigour or intellectual depth, Rosenberger quietly proves himself to be a natural-born teacher and storyteller […]”

What stands out, especially when Rosenberger starts talking taxonomy and evolution, is how well-written and accessible the material here is. He takes his time to enlighten you on the history, utility, and inner workings of zoological nomenclature, making the observation that “names can reflect evolutionary hypotheses“. Here, finally, I read clear explanations of terms such as incertae sedis (of uncertain taxonomic placement), monotypic genera (a genus consisting of only a single species), or neotypes (a replacement type specimen). Similarly, there are carefully wrapped lessons on how science is done—on the distinction between scenarios and hypotheses, or how parsimony and explanatory efficiency are important when formulating hypotheses. Without ever losing academic rigour or intellectual depth, Rosenberger quietly proves himself to be a natural-born teacher and storyteller, seamlessly blending in the occasional amusing anecdote.

A final two short chapters conclude the book. One draws on the very interesting question of biogeography, i.e. on how platyrrhine ancestors ended up in South America, which was long an island continent. Rosenberger convincingly argues against the popular notion of monkeys crossing the Atlantic on rafts of vegetation* and in favour of more gradual overland dispersal. The other chapter highlights their conservation plight as much of their tropical forest habitat has been destroyed by humans.

With New World Monkeys, Rosenberger draws on his 50+ years of professional experience to authoritatively synthesize a large body of literature. As such, this book is invaluable to primatologists and evolutionary biologists and should be the first port of call for anyone wanting to find out more about the origins, evolution, and behaviour of these South and Central American primates.

* One mechanism that Rosenberger does not mention is that tsunamis could be behind transoceanic rafting, as argued in a recent Science paper. This looked at marine species in particular and I doubt it would make much of a difference for terrestrial species. Most of the objections Rosenberger gives would still apply.

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

New World Monkeys

Other recommended books mentioned in this review:

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In the field of palaeoanthropology, one name keeps turning up: the Leakey dynasty. Since Louis Leakey’s first excavations in 1926, three generations of this family have been involved in anthropological research in East Africa. In this captivating memoir, Meave, a second-generation Leakey, reflects on a lifetime of fieldwork and research and provides an inspirational blueprint for what women can achieve in science.

The Sediments of Time: My Lifelong Search for the Past, written by Meave Leakey and Samira Leakey, published by Houghton Mifflin Harcourt in November 2020 (hardback, 396 pages)

With The Sediments of Time, Meave* follows a family tradition. Her husband Richard, and his parents Louis and Mary have all been the subject of (auto)biographies, now many decades old. Science writer Virginia Morell later portrayed the whole family in her 1999 book Ancestral Passions. Much has happened in the meantime, and though this book portrays Meave’s personal life, it heavily leans towards presenting her professional achievements, as well as scientific advances in the discipline at large. Thus, Meave’s childhood and early youth are succinctly described in the first 15-page chapter as she is keen to get to 1965 when a 23-year-old Meave starts working with Louis in Kenya.

Whereas Louis and Mary were famous for their work in Olduvai Gorge in Tanzania, Richard and Meave have made their careers around Lake Turkana in northern Kenya. The first two parts of the book take the reader chronologically through the various excavation campaigns. These include the decade-long excavations in and around Koobi Fora, one highlight of which was the find of Nariokotome Boy (also known as Turkana Boy), a largely complete skeleton of a young Homo erectus. The subsequent campaign in Lothagam yielded little hominin material but did reveal a well-documented faunal turnover of herbivore browsers being replaced by grazers with time. Meave has also described several new hominin species. This includes Australopithecus anamensis, which would be ancestral to Australopithecus afarensis (represented by the famous Lucy skeleton), and Kenyanthropus platyops, which would be of the same age as Ardipithecus ramidus. That last name might sound familiar, because…

“Woven into Meave’s narrative of exploration and excavation is an overview of how palaeoanthropology developed as a discipline, and what are some of its big outstanding questions.”

Having just reviewed Fossil Men, which portrayed the notorious palaeoanthropologist Tim White, I was curious to see what Meave had to say about him. In Fossil Men, Kermit Pattison already mentioned that she described White “with a note of sympathy” (p. 5), and she affirms that picture here, writing that he is “a meticulous scientist […] intolerant of bad science […] outspoken and frank […] although he was charming and a gentleman in less formal situations” (p. 136). And though they meet more than once to compare fossils, notes, and ideas, they remain at loggerheads over certain claims.

Woven into Meave’s narrative of exploration and excavation is an overview of how palaeoanthropology developed as a discipline, and what are some of its big outstanding questions. A recurrent theme is the influence of climate on evolution, often by impacting diet and available food sources. There is the difficult question of naming species and how much difference is enough to recognise a separate species, which ties into the whole lumpers vs. splitters debate in taxonomy. The latter readily name new species whereas the former (White being an example) point to sexual dimorphism and morphological variation and recognize only one or very few hominin species. Your stance in that debate affects what you think of Meave’s descriptions of Au. anamensis as being part of a lineage towards Au. afarensis, and whether K. platyops is a species distinct from Ar. ramidus (White obviously thinks not).

This discussion of topics relevant to palaeoanthropology strongly comes to the fore in the book’s third part, by which time Meave is examining the Homo lineage and the question where we appeared from. This sees her tackling topics such as human childbirth and the role of grandmothers, Lieberman’s hypothesis of endurance running as a uniquely human strategy to run prey to exhaustion, palaeoclimatology and the mechanism of the Milankovitch cycles, the spread of Homo erectus around the globe (the Out of Africa I hypothesis), and the use of genetics to trace deep human ancestry. I feel that Meave overstretches herself a little bit in places here. Though her explanations are lucid and include some good illustrations, some relevant recent literature, on e.g. ancient DNA and Neanderthals is not mentioned.

“Meave can draw on a deep pool of remarkable and amusing anecdotes that are put to good use to lighten up the text. And though the focus is on her professional achievements and the science, real life interrupts work on numerous occasions.”

Meave can draw on a deep pool of remarkable and amusing anecdotes that are put to good use to lighten up the text. And though the focus is on her professional achievements and the science, real life interrupts work on numerous occasions. Some of these are joyful, such as the birth of her daughters Louise and Samira. Some are a mixed blessing, such as Richard’s career changes, first when Kenya’s president hand-picks him to lead the Kenya Wildlife Service and combat rampant elephant poaching, then when he switches to attempting political reform. It removes him from palaeoanthropology and their time together in the field. Other occasions are outright harrowing, such as Richard’s faltering kidneys that require transplantations, or the horrific plane crash that sees him ultimately lose both legs despite extended surgery.

Illustrator Patricia Wynne contributes some tasteful drawings to this book, though the figure legends do not always clarify the important details these images try to convey. And I would have loved to see some photos of important specimens, whether during excavation or after preparation, especially given how much Meave focuses on the scientific story in this book. Many specimens are described in great detail but the colour plate section mostly contains photos of the Leakeys and collaborators in the field. Another minor point of criticism is that I was not clear on Samira’s part in writing this book. The dustjacket mentions her as a co-author, but the story is told exclusively through Meave’s eyes, and the acknowledgements do not clarify Samira’s role. I am left to surmise that Meave and Samira together drew on their store of memories for this book.

These minor criticisms notwithstanding, I found The Sediments of Time an inspiring memoir that provided a (for myself long-overdue) introduction to the Leakey dynasty. Meave has led a charmed existence and she is a fantastic role model for women in science.

* I normally refer to authors by their last name but, for obvious reasons and with all due respect, I will be deviating from that habit here and mention the various Leakeys by their first name.

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

The Sediments of Time

Other recommended books mentioned in this review:

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In his book Half-Earth, the famous biologist E.O. Wilson proposed setting aside half of the planet’s surface for conservation purposes. Deborah Rowan Wright will do you one better; given how important they are for life on the planet, how about we completely protect the oceans. What, all of it? Yes, not half, all of it. We need a gestalt shift, from “default profit and exploitation to default care and respect” (p. 11). Such a bold proposal is likely to elicit disbelief and cynicism—”Impossible!”—and Wright has experienced plenty of that. But hear her out, for sometimes we are our own worst enemy. Future Sea is a surprisingly grounded, balanced, and knowledgeable argument that swayed me because, guess what, the oceans are already protected.

Future Sea: How to Rescue and Protect the World’s Oceans, written by Deborah Rowan Wright, published by The University of Chicago Press in November 2020 (hardback, 192 pages)

This was the book’s most surprising revelation, at least for me. Legally speaking, the oceans are already under full protection. Having worked on topics such as ocean governance reform and public-trust law, Wright is perfectly positioned to dig into law statutes and serve up the relevant sections to prove her point. Between the 1982 United Nations Convention on the Laws of the Sea (UNCLOS III), the 1992 Convention on Biodiversity, and a raft of other global codes and treaties, 96.5% of the Earth’s oceans are already legally protected from exploitation, pollution, and other miscreants. This is where Wright starts asking the first of a series of very simple, seemingly naïve questions, a strategy she repeats throughout the book. The laws are there, why are they not working?

Unfortunately, like so many other international laws, they are paper tigers that are not really enforced. We have no planetary government, if you will, that has the power to hold individual countries to account. And although countries can exert pressure on one another via high-level organisations such as the United Nations: “when it comes to the sea the weight of the upright majority isn’t available to force compliance because much of the upright majority is itself breaking the laws that protect it” (p. 22).

Of all the perils facing our oceans that Wright mentions—plastic pollution, deep-sea mining, marine aquaculture, climate change, ocean acidification, coral bleaching, ghost fishing—she focuses on overfishing. She explains that vital concept of shifting baseline syndrome: the creeping form of collective amnesia that makes each generation accept a progressively more degraded environment as the new normal. How industrial-scale overfishing came about, and how government subsidies are now keeping it afloat. And how many regulatory bodies such as Regional Fisheries Management Organizations seem set up to fail by focusing on profit rather than protection. The International Commission for the Conservation of Atlantic Tuna (ICCAT) is mentioned here as a particularly egregious example.

“[…] Wright starts asking the first of a series of very simple, seemingly naïve questions, a strategy she repeats throughout the book. The laws are there, why are they not working?”

However, as she clarifies early on, “Protection doesn’t necessarily mean you can’t use something. It can also mean using something well” (p. 12–13). She is balanced enough in her argumentation to highlight that properly managed large-scale fisheries do not necessarily deplete fish populations (this was also an important theme of Ocean Recovery). Furthermore, the benefits of Marine Protected Areas and marine reserves have been well documented. Fish and other species can recover so quickly that even sceptical fishermen frequently become their staunchest defenders when their livelihoods improve again. Next to these top-down approaches, she discusses successful examples of community-based marine conservation, such as small-scale fisheries in Fiji and Palau.

Another important concept to understand is how the sea is divvied up. Every coastal country has an Exclusive Economic Zone (EEZ) that extends for two hundred miles seawards where they have exclusive jurisdiction. Everything outside of that (64% of ocean surface, 95% of ocean volume) is the high seas. A global commons* that, on paper, should be a jointly owned resource set aside for public use. In reality, it is a lawless wild west where some of the most depraved excesses of human cruelty play out. Yet, where overfishing is concerned, it need not be so. Ecosystem-based management, which considers whole ecosystems with all their interdependencies, is all the rage nowadays. We already have an example of this strategy working on the high seas: the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR), which was initially negotiated to protect Antarctic krill.

So, how can Wright’s bold plan of protecting the oceans become reality, she asks? In short by modernizing, implementing, and enforcing the law. As she shows here, all three steps are already underway or can be achieved. Political inertia is great, however, and time is running out. So, how do you get governments to act now? As Adam Ansel once wrote in Playboy, horrified: “we have to fight our own government to save our environment” (p. 79). Recent years have seen unprecedented legal cases where citizens have taken governments to court for neglecting environmental laws. And won. We, the people, have to hold them accountable, for they do not have to live with the repercussions of their poor decisions. Wright pointedly observes of politicians and business leaders that: “They’re mostly wealthy men in their fifties, sixties, and seventies and will be dead before very long” (p. 84).

“[…] Wright [points] out the power of language in shaping our perception. Take that loaded term “ocean management” […] “we should be managing ourselves […] “Ocean management” then becomes “people management”“.”

At this point in the book I started shifting in my chair uneasily. As I have written elsewhere, I am frustrated with the environmental movement’s narrative that casts politics and business as evil overlords. These discussions are hollow, hypocritical even, if they do not also consider the question of self-limitation: what is each of us willing to forego and give up for a better world?

I was very pleased, therefore, that Wright fully acknowledges and embraces this ethos. Best of all, she discusses more than just token efforts such as “shop responsibly” and “avoid single-use plastics”, tackling the big topics such as dropping meat and dairy from your diet and, significantly, having fewer children (I am so pleased to see this becoming part of the mainstream conversation around environmental issues). On that note, one last noteworthy thing is how Wright takes a leaf from Eileen Crist’s Abundant Earth when it comes to pointing out the power of language in shaping our perception. Take that loaded term “ocean management”. Given that oceans have existed for billions of years before we appeared (and did just fine, thank you very much) “we should be managing ourselves […] “Ocean management” then becomes “people management”” (p. 97)

I admit that Wright’s initial brief raised my eyebrows. However, her even-handed treatment of the subject and her insights into environmental law quickly tempered my scepticism. The way forward proposed here will not be easy, and she never pretends it will be, but the urgency with which she makes her case is utterly convincing. Future Sea is a galvanising book.

* The term “commons” was made famous by ecologist Garrett Hardin’s 1968 Science paper The Tragedy of the Commons, though it need not be a tragedy, political economist Elinor Ostrom would later argue in Governing the Commons.

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

Future Sea

Other recommended books mentioned in this review:

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