PREFACE

Dinosaur Odyssey explores two worlds: the ancient world of dinosaurs and the presentday world of dinosaur paleontology. Combining current science with personal stories from the field, the book conveys the entire prehistoric odyssey of dinosaurs, from humble origins on the supercontinent Pangaea, to the largest land animals the planet has ever known, and, finally, to an abrupt and catastrophic demise. Rather than focus solely on the “charismatic megafauna” of the time, the scope extends to encompass the shifting web of life on Earth and the roles that dinosaurs played in this evolutionary drama. Woven into the story are the latest discoveries and controversies. Why did gargantuan body sizes evolve so many times within dinosaurs? Were these famed prehistoric animals warm- or cold-blooded? In what ways was the hothouse Mesozoic world similar to and different from our own? How did dinosaurs go extinct and what meaning do they have for our lives today? Dinosaur Odyssey tackles these questions and many more.

Arguably, the most recent previous attempt by a paleontologist to synthesize the cutting edge of dinosaur paleontology was Robert Bakker’s 1986 book, The Dinosaur Heresies. Bakker, a leading figure in the 1970s “Dinosaur Renaissance,” portrayed these animals as highly dynamic—hot-blooded, active, and intelligent—much more similar to modern-day mammals and birds than to “dim-witted” reptiles. Bakker’s efforts to popularize this revitalized view of dinosaurs, combined with those of other paleontologists such as Jack Horner, reinvigorated popular interest in dinosaurs, eventually resulting in books and movies like Jurassic Park.

Dinosaur paleontology also underwent a dramatic surge in the wake of the Dinosaur Renaissance. Now rescued from their swamp-dwelling, tail-dragging torpor, these supercharged giants became a major research focus for enthusiastic young scientists. Indeed, the quarter century since the mid-1980s represents the most active period ever in dinosaur science. As a result, more dinosaurs have been named during the past 25 years than in all prior history. Entire groups of dinosaurs such as the plant-eating therizinosaurs and the meat-eating abelisaurs were virtually unknown prior to the 1990s. Many of these creatures were discovered on Southern Hemisphere landmasses, opening an entirely new window into Mesozoic Earth. Fieldwork in Asia has revealed a surprising and wondrous menagerie of feathered dinosaurs, documenting an intimate evolutionary relationship between T. rex and your Thanksgiving turkey. Meanwhile, in North America, the pace of research greatly accelerated, yielding amazing insights into dinosaur reproduction, growth, behavior, and ecology. This period also witnessed the first comprehensive use of high technology to study dinosaurs, with techniques like electron microscopy, histology, and computed tomographic (CT) scanning providing stunning answers to previously unapproachable questions.

To date, no book for a general audience has addressed this exciting time in the most popular of sciences. Dinosaur Odyssey fills that gap. To my mind, all science writing should follow Albert Einstein’s dictum: “Make everything as simple as possible, but not simpler.” Throughout the chapters that follow, I have done my best to achieve this goal. Use of some technical terminology is, of course, unavoidable, but recurring terms that may be unfamiliar to many readers (noted with capital letters in the text) are defined in a glossary section at the end of the book. As with any general interest science book, this one represents my own unique perspective. Along with simplicity, I have aspired toward a balanced synthesis of the various ideas currently debated by dinosaur experts, yet the end result inevitably reflects my own professional experiences and biases.

The story builds in a stepwise fashion, progressing through three major parts, each more integrative than its predecessor. Following an introduction in chapter 1, the first of these parts (chapters 2–5) presents some of the raw materials necessary for reconstructing the Mesozoic web of life. First up is the amazing evolutionary history that gave rise to Mesozoic Earth, from its stardust beginnings 14 billion years ago to the Triassic origin of dinosaurs about 230 million years ago. Chapter 3 shifts focus to the physical aspects of the Mesozoic world, among them the restless dynamics of Earth’s interior and the hothouse climates that far exceeded the direst present-day projections of global warming. Finally, chapters 4 and 5 explore ecology and evolution, respectively—the dual themes of this book and the twin forces that guided the building (and rebuilding) of the dinosaurs’ world.

The next section of the book (chapters 6–10) delves deeper, further integrating dinosaurs into their prehistoric web of life and making use of the previously described raw materials to weave a number of critical threads. Successive chapters discuss the flow of energy and the cycling of nutrients, first from plants to herbivores, then from herbivores to carnivores, and, finally, from all of these life-forms to decomposers and back to plants. Dinosaurs take their rightful place in this ancient web of relationships as the dominant, large-bodied, land-dwelling consumers of plants and meat. I then turn to the spectacular array of horns, crests, spikes, and other bony “bells and whistles” in an attempt to figure out why so many dinosaurs were not only big but truly bizarre. Also discussed here is dinosaur physiology—the famous warm- versus cold-blooded debate—in which I present a new hypothesis linking the evolution of metabolism with the recurring appearance of giants.

The final section of the book (chapters 11–15) is the most synthetic. The ecoevolutionary threads of earlier chapters are now used to spin some Mesozoic webs and present an up-to-date summary of the dinosaur odyssey. We begin with the origin of dinosaurs in the Triassic Period, investigating whether their marvelous success on land was the result of good fortune or evolutionary superiority. Moving forward in time to the Jurassic Period, I tackle a profound paleontological conundrum: how did so many varieties of dinosaurs—many of them larger than modern elephants—manage to live side by side? In the succeeding Cretaceous Period, the story shifts to the best-known case study in dinosaur evolution—the parade of forms that existed on the island landmass of western North America for tens of millions of years. Eventually, of course, the dinosaurs went extinct. Or did they? The saga now turns to the disappearance of the dinosaurs 65.5 million years ago, and to their continued legacy to the present day. Finally, the epilogue explores the meaning of dinosaurs for humans, arguing that they still have much to teach us; indeed, dinosaurs might even play a significant role in the persistence of our species.

In the end, Dinosaur Odyssey is more than a book about dinosaurs. It’s a book about how the world works, with dinosaurs serving as the primary protagonists. Highlighting the twin themes of ecology and evolution, I attempt to demonstrate how any ecosystem, past or present, is the culmination of moment-to-moment energy flow (ecology) married to the flow of information over millions of years (evolution). Many of the topics addressed—such as extinction and global warming—have direct relevance to our lives today. Although the book is intended for anyone with an interest in dinosaurs and science, it is my hope that science educators in particular will embrace some of the approaches presented here, using dinosaurs as a vehicle to address a broad range of topics. Ultimately, it is my hope that readers will come to see the odyssey of dinosaurs not merely as a tale of prehistoric monsters in some distant land, but rather a major chapter in our own ongoing story.