Table Of ContentDinosaur 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
intotheprimaryliterature,andwillactaspointersforfuturedirectionsforresearch.Aswellas
volumes on individual groups, the Series will also deal with topics that have a cross-cutting
relevance,suchastheevolutionofsignificantecosystems,particularkeytimesandeventsinthe
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.
COMPANIONWEBSITE
Thisbookhasacompanionwebsite:
www.wiley.com/go/brusatte/dinosaurpaleobiology
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Dinosaur
Paleobiology
Stephen L. Brusatte
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LibraryofCongressCataloging-in-PublicationData
Brusatte,Stephen.
Dinosaurpaleobiology/StephenL.Brusatte.
p. cm.– (Topicsinpaeobiology)
Includesbibliographicalreferencesandindex.
ISBN978-0-470-65657-0(hardcover:alk.paper) 1. Dinosaurs. 2. Paleobiology. I. Title.
QE861.4.B7862012
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Setin9/11.5ptTrumpMediaeval-RomanbyThomsonDigital,Noida,India
1 2012
Dedication
To my wife, Anne
Contents
Foreword ix
Preface xi
Acknowledgments xiii
Chapter1 AnIntroductiontoDinosaurs 1
Chapter2 HardTissues 29
Chapter3 SoftTissues 65
Chapter4 Phylogeny 88
Chapter5 Form 117
Chapter6 LocomotionandPosture 135
Chapter7 FeedingandDiet 159
Chapter8 Reproduction,Growth,andPhysiology 191
Chapter9 PaleoecologyandDwelling 227
Chapter10 MacroevolutionandExtinction 242
References 262
Index 309
Platesectionbetweenpp.130and131
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
agineduniversesofpastlife,allowingustoexplore fictionauthor.DuringtheMesozoic,thesauropod
times when the world was entirely different and dinosaurssolvedbasicphysiologicalproblemsthat
whensomeorganismscoulddothingsthatarenot allowedthemtoreachbodymassestentimesthose
achievedbyanythingnowliving. of the largest elephants today. Further, the giant
Much current work on biodiversity addresses pterosaur Quetzalcoatlus was larger than any fly-
questionsoforigins,distributions,andfuturecon- ing bird, and so challenges fundamental assump-
servation. Phylogenetic trees based on extant or- tionsinbiomechanics.
ganismscangivehintsabouttheoriginsofclades Books in the Topics in Paleobiology series will
and help answer questions about why one clade featurekeyfossilgroups,keyevents,andanalytical
mightbemorespecies-rich(“successful”)thanan- 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 phylogeneticdebates.
fuller impression of early clade histories, and so Thebookswillprovideasummaryofthecurrent
expandingourunderstandingofthedeeporiginsof stateofknowledge,atrustedrouteintotheprimary
biodiversity. literature,andwillactaspointersforfuturedirec-
Inthefieldofglobalchange,paleobiologistshave tionsforresearch.Aswellasvolumesonindividual
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 tionofsignificantecosystems,particularkeytimes
paleobiological histories can be matched to evi- andeventsinthehistoryoflife,climatechange,and
denceofchangesinthephysicalenvironment,such theapplicationofnewtechniquessuchasmolecu-
asvaryingtemperatures,sealevels,episodesofmid- larpaleontology.
oceanridgeactivity,mountainbuilding,volcanism, The books are written by leading international
continental positions, and impacts of extraterres- experts and will be pitched at a level suitable for
trialbodies.Studiesoftheinfluenceofsuchevents advanced undergraduates, postgraduates, and re-
andprocessesontheevolutionoflifeaddresscore searchersinboththepaleontologicalandbiological
questions about the nature of evolutionary pro- sciences.
cessesonthelargescale.
Asexamplesofunimagineduniverses,oneneed MichaelBenton,
only think of the life of the Burgess Shale or the Bristol,
times of the dinosaurs. The extraordinary arthro- November2011
ix
Preface
Dinosaursareeverywherethesedays.Theyarethe proceeding at a frenetic pace, as illustrated by a
mostpopularexhibitsinmanymuseums,thestars simple statistic: during 2010, the year I proposed
of movies and the focus of television documen- andbeganwritingthisbook,some63newspeciesof
taries,thepitchmeninadvertisingcampaignsand dinosaurswerediscovered.That’sastupendousrate
the subject of gushing articles in magazines and ofoveronenewspeciesperweek,whichhaslargely
newspapers. Looking at how dinosaurs are por- beenfueledbyagreatincreaseinfieldworkexplora-
trayedinthepopularpress,itiseasytolumpthem tion (especially in China and South America) and
togetherwithleprechauns,unicorns,anddragons– an ever-expanding roster of graduate students and
creaturesofmythandiconiclorethatonlyexistin other young researchers choosing to study
theimaginationsofchildrenandthewhimsyofpop dinosaurs.Andnotonlyisourstockpileofdinosaur
culture.Butdinosaursarenotcreaturesoffantasy– fossilsgrowingatanexponentialpace,butsoisthe
they were real animals, of many fantastic shapes developmentofnewresearchtechniques.Itusedto
andsizes,thatdominatedterrestrialecosystemsfor be that paleontologists could pontificate on the
anastoundingspanofover160millionyears.They biology,evolution,andextinctionofdinosaursbased
were living, breathing, feeding, moving, reprodu- onlyontheflimsiestscrapsofevidence,interpreted
cing, evolving organisms that originated in the withahealthydoseofimaginationandasnickering
aftermath of the worst mass extinction in earth dismissal of the explicit, quantitative, repeatable
history,rosetodominanceasasupercontinentwas methodologiesthathavelongbeenthenorminmost
splitting and climates were fluctuating, evolved other sciences. Those days are long gone. Today,
intosomeofthelargestandmostfearsomeanimals dinosaur paleontology is a dynamic science that
the planet has ever seen, and then suddenly went demandsevidence-basedrigorandisfirmlyintegr-
extinctrightatthesametimethatagiantcometor atedwithmanyotherscientificdisciplines.Indeed,
asteroid slammed into the earth and supervolca- researchersoftendrawfromadiverserepertoireof
noeswerebelchingriversoflava.Andperhapsmost anatomy,geology,chemistry,physics,mathematics,
astonishingofall,theseancientcreatures,sooften and statistics when studying dinosaurs. It is not
symbolsoflethargyandfailure,weretheancestors uncommon to see advanced calculus used to esti-
of one of the most successful groups of living matedinosaurbodymasses,computerizedengineer-
animals:thebirds. ing analyses marshaled to test whether certain
The scientific study of dinosaurs has been dinosaurswerecapableoffeedingormovingacer-
experiencing a remarkable renaissance over the tain way, or statistics utilized to explicitly assess
pastcoupleofdecades.Scientificunderstandingof whether some dinosaurs were evolving faster or
dinosaur anatomy, biology, and evolution has ad- slowerthanothers.
vancedtosuchadegreethatpaleontologistsoften Thebreadthofcurrentdinosaurresearchisvast.
know more about 100 million-year-old dinosaurs Somescientistsspendtheircareersdiscoveringand
thanmanyspeciesoflivingorganisms.Researchis describingnewspecies,othersmayfocussolelyon
xi
anatomy or genealogy, and others concentrate perspectivethathasyettobetappedbytheover-
on studying dinosaur locomotion or feeding. In saturated dinosaur book market. I have been
general, though, all contemporary work on dino- brought up and trained within the dynamism of
saurs provides evidence for addressing two main contemporary dinosaur research, and have been
questions. First, how did dinosaurs function as experiencingtheexplosivegrowthofthisfieldasa
livinganimals?Second,whatisthegrandnarrative dizzying cocktail of new discoveries and techni-
of dinosaur evolution across the Mesozoic? The ques have enabled modern scientists to under-
onlywaytoattackthesequestionsinadefensible stand dinosaurs in unprecedented detail. In
competent manner is to interpret the primary many ways this book is a personal journey. I do
evidence–theactualdinosaurfossilsthatprovide notpretendthatthisbookisanexhaustiveency-
a bedrock for the entire enterprise of dinosaur clopedia of everything that is currently known
research – using explicit quantitative methodolo- about dinosaurs, or a technical critique of the
gies.Theemerginganswerstothesequestions,and minutiae of every method and each piece of evi-
theevidenceandmethodsthatarerevealingthem, dence.Instead,whatIpresentismyunderstanding
arethefocusofthisbook.Like anyscience,dino- of dinosaur biology and evolution – the under-
saur paleontology is constantly changing as new standing of a student actively learning about
fossils are found and new research techniques are dinosaurs and in the midst of planning his own
developedandrefined.Ourknowledgeofdinosaur researchprogramandcareer.IpresentwhatIfind
biologyandevolutionisshiftingfast,andthisbook interestingandempowering,whatIthinkismost
is an attempt tocapture what is currently known important and exciting about contemporary
about this remarkable group of ancient creatures research,andwhereIthinkthefieldisheading.
thatdominatedourplanetforsolong. So,then,whatdoscientistsactuallyknowabout
From a more personal standpoint, this book is dinosaurs?Asitturnsout,thetruthaboutdinosaur
alsoayoung,perhapsbrazen,researcher’sexami- biology and evolution is surely more fascinating
nationofhisfieldofstudy.Iaminthesomewhat thaneventhemostsensationaldinosaurdocumen-
unusual position of writing this book as a PhD taryormovie,andmorethanfascinatingenoughto
student–ascientistwithoutanadvanceddegree, fuelthepassionofthismemberoftheMTVgenera-
withlessthanadecadeofresearchexperience,who tion.Indeed,withoutevenahintofhyperbole,the
hasnothadthetimeandwisdomto(atleastyet) story of dinosaur evolution is one of the greatest
makeasubstantialmarkonthefield.Butalthough storiesevertold.
I may not be the most traditional author of a
technical dinosaur book, and although perhaps I SteveBrusatte
should be focusing more on my thesis than on NewYork,USA
writing books, I feel that I am able to present a September1,2011
xii
PREFACE
