Topics in Paleobiology The study of dinosaurs has been experiencing a remarkable renaissance over the past few decades. Scientifi c understanding of dinosaur anatomy, biology, and evolution has advanced to such a degree that paleontologists often know more about 100-million-year-old dinosaurs than many species of living organisms. This book provides a contemporary review of dinosaur science intended for students, researchers, and dinosaur enthusiasts. It reviews the latest knowledge on dinosaur anatomy and phylogeny, Brusatte how dinosaurs functioned as living animals, and the grand narrative of dinosaur evolution across the Mesozoic. A particular focus is on the fossil evidence and explicit methods that allow paleontologists to study dinosaurs in rigorous detail. Scientifi c knowledge of dinosaur biology and evolution is shifting fast, Dinosaur and this book aims to summarize current understanding of dinosaur science in a technical, but accessible, style, supplemented with vivid photographs and illustrations. Paleobiology Dinosaur The Topics in Paleobiology Series is published in collaboration with the Palaeontological Association, Paleobiology and is edited by Professor Mike Benton, University of Bristol. Stephen Brusatte is a vertebrate paleontologist and PhD student at Columbia University and the American Museum of Natural History. His research focuses on the anatomy, systematics, and evolution of fossil vertebrates, especially theropod dinosaurs. He is particularly interested in the origin of major groups such Stephen L. Brusatte as dinosaurs, birds, and mammals. Steve is the author of over 40 research papers and three books, and his work has been profi led in The New York Times, on BBC Television and NPR, and in many other press outlets. Photography: Mick Ellison Life reconstructions: Jason Brougham Skeletal reconstructions: Scott Hartmann A companion website with additional resources is available at: www.wiley.com/go/brusatte/dinosaurpaleobiology Cover image: The small feathered dromaeosaurid Sinornithosaurus (“Dave” specimen) from the Early Cretaceous of China. Photograph by Mick Ellison. Cover design by Design Deluxe Series Editor: Professor Michael J. Benton Dinosaur Paleobiology Books in the Topics in Paleobiology series will feature key fossil groups, key events, and analytical methods, with emphasis on paleobiology, large-scale macroevolutionary studies, and the latest phylogenetic debates. The books will provide a summary of the current state of knowledge and a trusted route into the primary literature, and will act as pointers for future directions for research. As well as volumes on individual groups, the Series will also deal with topics that have a cross-cutting relevance, such as the evolution of significant ecosystems, particular key times and events in the history of life, climate change, and the application of new techniques such as molecular paleontology. The books are written by leading international experts and will be pitched at a level suitable for advanced undergraduates, postgraduates, and researchers in both the paleontological and biological sciences. The Series Editor is Mike Benton, Professor of Vertebrate Palaeontology in the School of Earth Sciences, University of Bristol. The Series is a joint venture with the Palaeontological Association. COMPANION WEBSITE This book has a companion website: www.wiley.com/go/br usatte/dinosaurpaleobiology with Figures and Tables from the book for downloading Dinosaur Paleobiology Stephen L. Brusatte This edition first published 2012 Ó 2012 by John Wiley & Sons, Ltd. Wiley-Blackwell is an imprint of John Wiley & Sons, formed by the merger of Wiley’s global Scientific, Technical and Medical business with Blackwell Publishing. Registered office: John Wiley & Sons, Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial offices: 9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK 111 River Street, Hoboken, NJ 07030-5774, USA For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley-blackwell. The right of the author to be identified as the author of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. All rights reserved. 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Library of Congress Cataloging-in-Publication Data Brusatte, Stephen. Dinosaur paleobiology / Stephen L. Brusatte. p. cm. – (Topics in paeobiology) Includes bibliographical references and index. ISBN 978-0-470-65657-0 (hardcover : alk. paper) 1. Dinosaurs. 2. Paleobiology. I. Title. QE861.4.B786 2012 567.9–dc23 2011050466 A catalogue record for this book is available from the British Library. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Set in 9/11.5pt Trump Mediaeval-Roman by Thomson Digital, Noida, India 1 2012 Dedication To my wife, Anne Contents Foreword ix Preface xi Acknowledgments xiii Chapter 1 An Introduction to Dinosaurs 1 Chapter 2 Hard Tissues 29 Chapter 3 Soft Tissues 65 Chapter 4 Phylogeny 88 Chapter 5 Form 117 Chapter 6 Locomotion and Posture 135 Chapter 7 Feeding and Diet 159 Chapter 8 Reproduction, Growth, and Physiology 191 Chapter 9 Paleoecology and Dwelling 227 Chapter 10 Macroevolution and Extinction 242 References 262 Index 309 Plate section between pp. 130 and 131 vii Foreword Paleobiology is a vibrant discipline that addresses pods and other animals of the Cambrian sites of current concerns about biodiversity and about exceptional preservation sometimes seem more global change. Further, paleobiology opens unim- bizarre than the wildest imaginings of a science agined universes of past life, allowing us to explore fiction author. During the Mesozoic, the sauropod times when the world was entirely different and dinosaurs solved basic physiological problems that when some organisms could do things that are not allowed them to reach body masses ten times those achieved by anything now living. of the largest elephants today. Further, the giant Much current work on biodiversity addresses pterosaur Quetzalcoatlus was larger than any fly- questions of origins, distributions, and future con- ing bird, and so challenges fundamental assump- servation. Phylogenetic trees based on extant or- tions in biomechanics. ganisms can give hints about the origins of clades Books in the Topics in Paleobiology series will and help answer questions about why one clade feature key fossil groups, key events, and analytical might be more species-rich (“successful”) than an- methods, with emphasis on paleobiology, large- other. The addition of fossils to such phylogenies scale macroevolutionary studies, and the latest can enrich them immeasurably, thereby giving a phylogenetic debates. fuller impression of early clade histories, and so The books will provide a summary of the current expanding our understanding of the deep origins of state of knowledge, a trusted route into the primary biodiversity. literature, and will act as pointers for future direc- In the field of global change, paleobiologists have tions for research. As well as volumes on individual access to the fossil record and this gives accurate groups, the Series will also deal with topics that information on the coming and going of major have a cross-cutting relevance, such as the evolu- groups of organisms through time. Such detailed tion of significant ecosystems, particular key times paleobiological histories can be matched to evi- and events in the history of life, climate change, and dence of changes in the physical environment, such the application of new techniques such as molecu- as varying temperatures, sea levels, episodes of mid- lar paleontology. ocean ridge activity, mountain building, volcanism, The books are written by leading international continental positions, and impacts of extraterres- experts and will be pitched at a level suitable for trial bodies. Studies of the influence of such events advanced undergraduates, postgraduates, and re- and processes on the evolution of life address core searchers in both the paleontological and biological questions about the nature of evolutionary pro- sciences. cesses on the large scale. As examples of unimagined universes, one need Michael Benton, only think of the life of the Burgess Shale or the Bristol, times of the dinosaurs. The extraordinary arthro- November 2011 ix Preface Dinosaurs are everywhere these