The Sauropods: Evolution and Paleobiology

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THE SAUROPODS: EVOLUTION AND PALEOBIOLOGY. Kristina A. Curry Rogers and Jeffrey A. Wilson (eds). 2005. The University of California Press, Berkeley, California. ISBN 978-0-52024623-2 (hard cover). 358 p. $65.00 (hard cover).—The giant sauropods have captured the imagination of the public since their discovery. Their enormous size and morphological oddities embody the exotic nature of dinosaurs and present conundrums of physiology and biomechanics that have, for decades, challenged scientists who study them. The monophyly of sauropods as a group is unquestioned (Upchurch, 1998; Wilson and Sereno, 1998; Wilson, 2002; Upchurch et al., 2004), and their close relationship to prosauropods as an ancestral taxon is likewise robustly supported. However, relationships within the clade are less clear, a problem exacerbated by fragmentary remains and missing or incomplete skull material that would be diagnostic. Evolutionary relationships aside, this dinosaurian taxon poses many questions that were thought to be unanswerable. However, in the book The Sauropods, edited by K. Curry-Rogers and J. Wilson, many of these issues are addressed, and new light is being shed, not only on relationships, but on many aspects of the paleobiology of the group as a whole. New techniques, analytical approaches, and comparisons, coupled with new sauropod discoveries, are beginning to provide answers to questions regarding growth strategies (Chapter 11), feeding mechanisms and strategies (Chapters 4–6), behavior (Chapter 9) and even reproduction (Chapter 10). Most chapters in the multi-authored book end with a heartfelt dedication to Jack MacIntosh, whose unfailing passion for this wonderful group of animals has inspired many present and future generations of scientists. I am not a morphologist, or an expert in phylogenetic analyses, and sauropods are not the focus of my research. But I love dinosaurs, and I will not soon forget the pleasure of sitting next to Jack at a dinner after one of many meetings celebrating dinosaur diversity. I have never met a nicer, more humble, kind, warm human being—a rarity among academics devoted to obscure and esoteric studies, including paleontology. Jack’s passion for sauropods was and is immediately apparent, but his childlike curiosity for all things dinosaurian is captivating—and motivating as well. He has a gift for encouraging beginning and ‘old guard’ scientists alike, and his enthusiasm radiates to all who study any aspect of dinosaur science. These accolades to an exceptional scientist, and more, a wonderful human being, and the high praise and recognition of his contributions to this discipline, are richly deserved. The book ranges from overly technical in places to an almost folksy discussion of topics. The early chapters in this book are dedicated to the history of scientific investigation of the sauropods, and to the evolutionary relationships between sauropod clades and of sauropods to other dinosaurian taxa. The copious reference list at the end of every chapter provides a comprehensive summary of work done in the area discussed, and provides a wonderful starting place for students of dinosaur biology interested in any area of study. Chapter 1 is a thorough description of diagnostic characters that nest the sauropod clade within Saurischia, and that diagnose individual clades within Sauropoda. It also presents a brief history of the attempts to classify this group of dinosaurs and the various methods employed to do so. It also discusses the various ‘defining’ characters of sauropods, including elongation of cervical vertebrae and adaptations of the limbs to a columnar stance, requirements for terrestrial animals of such great mass. Chapter 2 embraces the outlandish and bizarre features of titanosaurs, arguably one of the most successful of sauropod linages, and describes the geographical and temporal distributions of this clade. CurryRogers segues nicely from the phylogenetic overview of sauropods presented in Chapter 1 to a narrower cladistic analysis of characters defining the titanosaurs within the sauropods. The discussion and diagnosis of Rapetosaurus krausei as a ‘keystone titanosaur’ provides some resolution to the phylogenetic and evolutionary picture of this dominant, widespread, diverse clade. The list of diagnostic characters provided in the appendix is impressive, and forms a robust framework for future phylogenetic hypotheses as new specimens are discovered and described. An informative discussion of fluctuating patterns of sauropod diversity is the focus of Chapter 3. The attempts to distinguish taphonomic artifacts from true evolutionary trends is thoughtful and emphasizes the need for consideration of sedimentary and stratigraphic context when attempting to discern true extinction and/or diversification events vs. number of opportunities to observe.