Table Of ContentJ.L.Cloudsley-Thompson
Ecology and Behaviour of Mesozoic Reptiles
John L.Cloudsley-Thompson
Ecology and Behaviour
of Mesozoic Reptiles
With 129 Figures and 4 Tables
Professor Dr.John L.Cloudsley-Thompson
10 Battishill Street
London,N1 1TE
UK
ISBN3-540-22421-1Springer-VerlagBerlinHeidelbergNewYork
Library of Congress Control Number: 2004112900
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Preface
Popular interest in dinosaurs and other Mesozoic reptiles began during the
thirddecadeofthe19thcentury,andhasincreasedcontinuallysincethattime.
In 1841, the name Dinosauria (‘terrible lizards’) was proposed by Richard
OwenattheannualmeetingoftheBritishAssociationfortheAdvancementof
Science,heldinPlymouth;itfirstappearedinprintthefollowingyear.During
subsequent decades, both scientific and popular interest were extended to
pterosaurs,mosasaurs,ichthyosaursandplesiosaurs.Mesozoicreptiles,espe-
ciallydinosaurs,likewiseearnedtheirplaceinsciencefiction,filmsandcomic
strips.ItisnocoincidencethatbothmywifeandIwerethrilledespeciallyby
SirArthurConan Doyle’sTheLostWorld (1912)whilst atschool.Anneeven
readitbytheflickeringlightofacoalfirewhilstinthesanatoriumquarantined
forchickenpox!EdgarRiceBurroughs,creatorofTarzan,andnumerousother
authorswrotestoriesaboutdinosaursduringthefirstpartofthe20thCentury,
whilsttheyappearedinmanyearlyfilms,notablyTheLostWorld(1925)and
King Kong(1933).
MyowninterestinMesozoicreptileswasawakenedattheageof6or7when
myparentsfirsttookmetotheNaturalHistoryMuseum,London.Iwasaston-
ishedbytheirwondroussizeandthesoberingthoughtthattheyhadalldisap-
pearedfromthefaceoftheearthsome65millionyearsago.Whenwegothome
Iaskedmyfather,What“Whatiftherewasadinosaurburiedunderneathour
house?”Ineverforgothisreply,“Thenthehousewouldhavetobepulleddown
togetitout.”AsIgrewolder,themysteryofdinosaurextinctionintriguedme
moreandmore.OnmyreturntoCambridgeafterWorldWarII,despiteavery
busytimetableandknowingthatIwouldnotattempttoansweranyquestions
onvertebratepalaeontologyintheNaturalScienceTriposPart2exam,Inever-
thelessattendedF.R.Parrington’slectures,asdidAlanCharig.Indeed,theCreta-
ceousextinctiondidnotimpingeuponmyownfieldsofresearchfor30years.By
thattime,anumberofclueshadbeenprovidedthathelpedtoexplainthemys-
tery .They came not only from palaeontological and geological studies,but
also from research on the physiology and ecology ofextant reptiles.
Inthepresentvolume,Ihaveattemptedtoprovideanotunbiasedsynthesis
ofcurrentviewsregardingtheecology,physiologyandbehaviourofMesozoic
reptiles, and to outline the various hypotheses that have been proposed to
explain their extinction.
London,Autumn2004 JohnCloudsley-Thompson
Acknowledgements
MywarmestthankstoProfDrMichaelBenton,authorofover40booksonevo-
lution,fossilsanddinosaurs,forinvaluableadviceandforhiskindnessinal-
lowingmetoplunderhismuchacclaimedVertebratePalaeontology.Ishould
alsoliketoexpressmyappreciationforthehelpandadviceof LauraTatham
whotypedthemanuscriptandofMichaelPalmer,archivisttoTheZoological
SocietyofLondon,whotracedsomeelusivereferencesforme.Onceagain,my
thankstoDrDieterCzeschlikandDrAndreaSchlitzberger,BiologyEditorial
Springer-Verlag,fortheirfriendlycooperation.Asalways,Iamdeeplyindebted
tomydearestwifeAnneforherwonderfulcompanionshipandadvice.Alison
Bailey,on behalf of the Editorial Board,kindly gave me permission to quote
fromanarticleofminethatfirstappearedinBiologist(InstituteofBiology)in
2001.Iamalsogratefultovariousartists,authorsandpublishersforgranting
permissiontoredrawandadaptcopyrightmaterial.Sourceshavebeencredited
bothinthetextandinthelegendstothefigures;fulldetailsarecitedinthebib-
liography.Everyreasonableefforthasbeenmadetotraceandobtainpermis-
sionbut,ifanycopyrightownershaveinadvertentlybeenoverlooked,Iwillbe
pleasedtomakethenormalarrangementsandgivefullacknowledgementsat
the first opportunity.
Contents
1 Classification................................................................................................... 1
1.1 Introduction ........................................................................................... 1
1.2 Amphibians ............................................................................................ 3
1.3 Reptiles ................................................................................................... 3
1.4 NoteonColoration ................................................................................ 7
2 DiversificationofPalaeozoicReptiles...........................................................9
2.1 Introduction ........................................................................................... 9
2.2 ContinentalDrift .................................................................................. 10
2.3 ReptilianAncestors .............................................................................. 10
2.4 AnapsidReptiles .................................................................................. 12
2.5 SynapsidReptiles ................................................................................. 14
3 TheMesozoicEnvironment ......................................................................... 19
3.1 Introduction ......................................................................................... 19
3.2 TheTriassicPeriod .............................................................................. 20
3.3 TheJurassicandCretaceousPeriods ..................................................20
4 AmphibiousandEarlyMarineMesozoicReptiles .....................................23
4.1 Introduction ......................................................................................... 23
4.2 Locomotion .......................................................................................... 24
4.3 Testudines ............................................................................................ 26
4.3.1 Respiration ................................................................................ 27
4.3.2 Evolution ................................................................................... 28
4.4 PlacodontsandNothosaurs ................................................................29
4.4.1 Placodonts ................................................................................. 29
4.4.2 Nothosaurs ................................................................................ 31
4.4.3 Claudiosaurians ........................................................................ 33
4.5 Thalattosaurs,MosasaursandOtherSeaLizards ..............................34
4.6 Champsosaurs,PhytosaursandCrocodilians....................................36
4.6.1 Choristodera.............................................................................. 36
4.6.2 Phytosaurs ................................................................................. 37
4.6.3 Crocodilians .............................................................................. 38
5 PlesiosaursandIchthyosaurs ...................................................................... 45
5.1 Introduction ......................................................................................... 45
5.2 Swimming............................................................................................. 46
X Contents
5.2.1 Plesiosaurs................................................................................. 46
5.2.2 Ichthyosaurs.............................................................................. 48
5.3 Plesiosaurs ............................................................................................ 51
5.3.1 PlesiosaurDiversification.........................................................51
5.4 Ichthyosaurs ......................................................................................... 54
5.4.1 IchthyosaurDiversification......................................................55
5.5 Conclusions .......................................................................................... 59
6 AerialMesozoicReptiles .............................................................................. 61
6.1 Introduction ......................................................................................... 61
6.2 GlidingReptiles .................................................................................... 63
6.3 PterosaurFlight.................................................................................... 67
6.4 LocomotionontheGround.................................................................70
6.4.1 BipedalLocomotion .................................................................70
6.4.2 QuadrupedalLocomotion ........................................................71
6.5 Rhamphorynchoids ............................................................................. 72
6.6 Pterodactyloids..................................................................................... 77
6.6.1 CretaceousPterosaurs ..............................................................79
6.7 LifeStyles .............................................................................................. 82
6.7.1 Feeding ...................................................................................... 82
6.7.2 Reproduction ............................................................................ 83
6.7.3 Enemies ..................................................................................... 85
6.8 Extinction ............................................................................................. 85
6.9 Summary .............................................................................................. 86
7 TerrestrialMesozoicReptiles:
Size,LocomotionandThermalPhysiology ................................................89
7.1 Introduction ......................................................................................... 89
7.2 QuadrupedalLocomotion ................................................................... 89
7.3 BipedalLocomotion............................................................................. 90
7.4 WeightandSizeLimits ........................................................................ 92
7.5 ThermalPhysiology ............................................................................. 99
7.5.1 BehaviouralThermoregulation..............................................100
7.5.2 ThermoregulatoryStructures.................................................102
7.6 Tachymetabolism............................................................................... 103
7.6.1 AnatomicalEvidence ..............................................................104
7.6.2 BoneHistology ........................................................................ 105
7.6.3 EnergyFlowandPredator:PreyRatios .................................107
7.6.4 PalaeolatitudinalDistribution................................................109
7.7 BradymetabolicThermoregulation...................................................110
7.8 HairandFeathers............................................................................... 111
7.9 Conclusions ........................................................................................ 111
Contents XI
8 Therapsids,AnapsidsandEarlyDiapsids.................................................113
8.1 Introduction ....................................................................................... 113
8.2 TherapsidsandtheOriginofMammals ...........................................113
8.3 Anapsids ............................................................................................. 116
8.4 EarlyDiapsids..................................................................................... 117
8.4.1 Lepidosauria............................................................................ 117
8.4.2 Squamata ................................................................................. 118
8.4.3 EarlyArchosauromorphs .......................................................120
9 TheDinosaurs:Weapons,DisplayandReproduction .............................125
9.1 TheEarliestDinosaurs....................................................................... 125
9.2 DinosaurWeapons............................................................................. 128
9.2.1 WeaponsofAttack..................................................................128
9.2.2 DefensiveWeapons.................................................................130
9.2.3 DefensiveDisplay.................................................................... 135
9.3 Reproduction...................................................................................... 136
9.3.1 AgonisticBehaviour ...............................................................136
9.3.2 CourtshipandMating ............................................................142
9.3.3 NestingBehaviour................................................................... 143
9.3.4 GrowthandDevelopment ......................................................147
10 HerbivorousDinosaurs .............................................................................. 149
10.1 Introduction ....................................................................................... 149
10.2 Teeth,GastrolithsandDigestion.......................................................149
10.3 BasalSauropodomorphs–Prosauropods ........................................151
10.4 Sauropods ........................................................................................... 153
10.5 HerbivorousBipeds ........................................................................... 156
10.5.1 FabrosauridsandHeterodontosaurids..................................157
10.5.2 Hypsilophodontids .................................................................158
10.5.3 Iguanodontids ......................................................................... 160
10.5.4 Hadrosaurids........................................................................... 160
10.5.5 Psittacosaurids ........................................................................ 162
10.5.6 Pachycephalosaurians ............................................................163
10.6 Horned,PlatedandArmouredDinosaurs .......................................163
10.6.1 Ceratopsians............................................................................ 163
10.6.2 Stegosaurs................................................................................ 165
10.6.3 Ankylosaurs ............................................................................ 166
10.7 Conclusions ........................................................................................ 168
11 CarnivorousDinosaurs .............................................................................. 171
11.1 Introduction ....................................................................................... 171
11.2 Dentition............................................................................................. 171
11.3 Ceratosaurs ......................................................................................... 172
11.3.1 Maniraptora ............................................................................ 174
11.3.2 Dromaeosaurids...................................................................... 176
XII Contents
11.3.3 Troodontids............................................................................. 177
11.3.4 Therizinosaurids–Segnosaurs ..............................................178
11.4 Carnosaurs.......................................................................................... 179
11.4.1 PredationandScavenging ......................................................180
11.4.2 Megalosaurids ......................................................................... 181
11.4.3 Spinosaurids............................................................................ 181
11.4.4 Allosaurids .............................................................................. 183
11.4.5 Tyrannosaurids ....................................................................... 184
11.5 TheOriginofBirds............................................................................. 185
11.5.1 Feathers ................................................................................... 186
11.5.2 Flight ........................................................................................ 187
11.6 Conclusions ........................................................................................ 188
12 TheCretaceousExtinction ......................................................................... 189
12.1 Introduction ....................................................................................... 189
12.1.1 MassExtinctions ..................................................................... 189
12.1.2 ThePermianExtinction .........................................................190
12.1.3 TheTriassicExtinction...........................................................191
12.2 TerminalMesozoicEvents ................................................................191
12.3 DinosaurExtinction:ImprobableHypotheses.................................192
12.4 CataclysmalHypotheses .................................................................... 193
12.4.1 ImpactwithaMeteoriteorBolide .........................................194
12.5 GradualistHypotheses....................................................................... 195
12.5.1 Longevity,InjuriesandDisease .............................................196
12.5.2 NutritionalFactors..................................................................197
12.5.3 ThermalEffects ....................................................................... 197
12.6 Conclusions ........................................................................................ 199
Epilogue............................................................................................................. 201
Bibliography ..................................................................................................... 203
SubjectIndex .................................................................................................... 213
