Early Flowers and Angiosperm Evolution

597 Pages·2011·7.82 MB·English

by  Else Marie Friis

Early Flowers and Angiosperm Evolution
Therecentdiscoveryofdiversefossilflowersandfloralorgans
inCretaceousstratahasrevealedastonishingdetailsaboutthe
structural and systematic diversity of early angiosperms.
Exploring the rich fossil evidence that has been accumulated
over the past three decades, this unique study follows the
evolutionary history of flowering plants from their earliest
phasesinobscuritytotheirdominanceinmodernvegetation.
The book provides comprehensive biological and geological
background information, before moving on to summarise the
fossilrecordindetail.Includingpreviouslyunpublishedresults
based on research into Earlyand Late Cretaceous fossil floras
from Europe and North America, the authors draw together
direct palaeontological evidence of the pattern of angiosperm
evolutionthroughtime.
Synthesising palaeobotanical data with information from
livingplants,thisbookexploresthelatestresearchinthefield
and highlights connections with phylogenetic systematics
aswellasthestructureandthebiologyofextantangiosperms.
Else Marie Friis isintheDepartmentofPalaeobotanyatthe
Swedish Museum of Natural History. Her research interests
includeCretaceousflowersandotherfossilreproductivestruc-
tures,withparticularfocusontheoriginandearlydiversification
ofangiospermsandrelatedseedplants.
Peter R. Crane is in the School of Forestry and Environ-
mentalStudiesatYaleUniversity.Hisresearchinterestsinclude
large-scale patterns and processes of plant evolution and
integrated palaeobotanical and neobotanical studies of plant
diversityandevolution.
Kaj Raunsgaard Pedersen is in the Department of
Geology at the Universityof Aarhus. His research interests
include integrated palynological and palaeobotanical studies
ofMesozoicseedplantswithparticularfocusonCretaceous
reproductivestructuresandfloweringplantevolution.

Early Flowers and Angiosperm Evolution
Else Marie Friis
Swedish Museum of Natural History,
Stockholm
Peter R. Crane
School of Forestry & Environmental Studies,
Yale University
Kaj Raunsgaard Pedersen
Department of Geology, University of Aarhus
Line drawings by Pollyanna von Knorring
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Thispublicationisincopyright.Subjecttostatutoryexception
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Firstpublished2011
PrintedintheUnitedKingdomattheUniversityPress,Cambridge
AcataloguerecordforthispublicationisavailablefromtheBritishLibrary
LibraryofCongressCataloging-in-PublicationData
Friis,ElseMarie.
Earlyflowersandangiospermevolution/ElseMarieFriis,PeterR.Crane,
KajRaunsgaardPedersen.
p. cm.
ISBN978-0-521-59283-3(Hardback)
1. Angiosperms,Fossil. 2. Angiosperms–Evolution. I. Crane,PeterR.
II. Pedersen,KajRaunsgaard. III. Title.
QE980.F752011
561–dc22
2011001815
ISBN978-0-521-59283-3Hardback
CambridgeUniversityPresshasnoresponsibilityforthepersistenceor
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Contents
Preface pageix 5 Angiospermsincontext:extantandfossil
seedplants 101
1 Introductiontoangiosperms 1 5.1 Angiospermsamongextantandfossil
1.1 Phylogeneticpositionofangiosperms 1 seedplants 101
1.2 Characteristicfeaturesofangiosperms 6 5.2 Bennettitales–Erdtmanithecales–Gnetales
1.3 Timingofangiospermdiversification 16 (BEG)group 104
1.4 Risetoecologicaldominance 19 5.3 Gnetales 105
5.4 Erdtmanithecales 114
2 Thenatureoftheangiospermfossil 5.5 Unassigneddispersedseedsofthe
record 23 BEGgroup 119
2.1 Understandingtheplantfossilrecord 23 5.6 Bennettitales(Cycadeoidales) 124
2.2 Theadequacyoftheangiospermfossil 5.7 Pentoxylales 130
record 38 5.8 OtherPalaeozoicandMesozoicseedplants 131
3 Theenvironmentalcontextofearly 6 Originandageofangiosperms 141
angiospermevolution 39 6.1 Hypothesesofseedplantrelationships 141
3.1 Palaeogeography 39 6.2 Originofangiospermstructure 150
3.2 Palaeoclimate 45 6.3 Theageofangiosperms 155
3.3 Climatechangeduringthe 6.4 Pre-Cretaceousangiosperm-likefossils 158
Cretaceous 50
3.4 Implicationsforangiosperm 7 Phylogeneticframeworkandthe
diversification 53 assignmentoffossilstoextantgroups 163
7.1 Earlyideasonangiospermphylogeny 163
4 Stratigraphicframeworkandkeyareas 7.2 Phylogeneticstudiesofangiospermsbasedon
forCretaceousangiosperms 55 moleculardata 163
4.1 Thestratigraphicframework 55 7.3 Angiospermphylogenygroupclassification
4.2 KeyareasforCretaceousangiosperms 56 (APGIII) 164
4.3 Europe 57 7.4 Angiospermphylogeny:futuredirections 167
4.4 EasternNorthAmerica 72 7.5 Assignmentoffossilstoextantgroups 168
4.5 WesternInterioroftheUnitedStates
andCanada 79 8 Fossilsnearthebaseoftheangiospermtree 169
4.6 Alaska 81 8.1 Early-divergingangiospermlineagesatthe
4.7 Greenland 82 ANITAgrade 169
4.8 Israel,JordanandLebanon 82 8.2 Amborellaceae 171
4.9 NorthAfrica 84 8.3 Nymphaeales 171
4.10 WestAfricaandBrazil 85 8.4 Austrobaileyales 176
4.11 Asia 88 8.5 Chloranthaceae 180
4.12 SouthernGondwanaandIndia 96 8.6 Ceratophyllaceae 185
v
vi Contents
9 Earlyfossilangiospermsofuncertain 13.7 Caryophyllales 315
relationships 189 13.8 Saxifragales 316
9.1 Putativeangiosperms 189
9.2 Fossilflowersattachedtoinflorescences 14Fossilsofcoreeudicots:rosids 327
andstems 192 14.1 Classificationofrosids 327
9.3 Isolatedflowersandfruitspreservedas 14.2 Fossilevidenceofrosids 327
compressions/impressions 200 14.3 Vitales 329
9.4 Permineralisedflowers 201 14.4 Fabids(EurosidsI) 329
9.5 Isolatedangiospermmesofossils 202 14.5 TheCOMclade 329
9.6 Dispersedmonoaperturatepollen 208 14.6 Thenitrogen-fixingclade 332
9.7 Fossilleavesofuncertainrelationships 215 14.7 Malvids(EurosidsII) 354
10Earlyfossilsofeumagnoliids 219
15Earlyfossilsofeudicots:asterids 361
10.1 Classificationofeumagnoliids 219
15.1 Classificationofasterids 361
10.2 Magnoliales 223
15.2 Cornales 363
10.3 Laurales 231
15.3 Ericales 365
10.4 Canellales 244
15.4 Lamiids(EuasteridsI) 378
10.5 Piperales 246
15.5 Boraginaceae,IcacinaceaeandVahliaceae 379
15.6 Garryales 381
11Fossilsofmonocots 249
15.7 Gentianales 381
11.1 Classificationofmonocots 249
15.8 SolanalesandLamiales 382
11.2 Fossilevidenceofmonocotdiversification 250
15.9 Campanulids(EuasteridsII) 382
11.3 Putativeearlymonocotfossils 250
15.10 Aquifoliales,EscallonialesandAsterales 383
11.4 Acorales 255
15.11 Bruniales,Apiales,Paracryphialesand
11.5 Alismatales 256
Dipsacales 385
11.6 Dioscoreales 266
11.7 Pandanales 266
16Patternsofstructuraldiversificationin
11.8 Liliales 267
angiospermreproductiveorgans 387
11.9 Asparagales 267
16.1 Inflorescencestructure 388
11.10 Commelinids 268
16.2 Floralorganisation 391
12Fossilsofeudicots:early-diverginggroups 275 16.3 Otheraspectsoffloralconstruction 412
12.1 Classificationofeudicots 275
12.2 Early-divergingeudicots 276 17Historyandevolutionofpollinationin
12.3 Fossilevidenceofeudicotdiversification 277 angiosperms 415
12.4 Fossilsofuncertainrelationships 277 17.1 Pollinationinextantnon-angiospermseed
12.5 Ranunculales 289 plants 415
12.6 Proteales 292 17.2 Pollinationinextantangiosperms 417
12.7 Sabiaceae 301 17.3 Insectsaspollinators 419
12.8 Buxales 303 17.4 Vertebratesaspollinators 426
12.9 Trochodendrales 308 17.5 Historyofpollinationinangiosperms 428
17.6 Large-scaletrendsinthehistoryof
13Fossilsofcoreeudicots:basallineages 311 angiospermpollination 441
13.1 Classificationofcoreeudicots 311
13.2 Earlyfossilevidenceofcoreeudicots 312 18Historyandevolutionofdispersalin
13.3 Gunnerales 312 angiosperms 445
13.4 Dilleniaceae 313 18.1 Dispersalinextantnon-angiosperm
13.5 Berberidopsidales 313 seedplants 445
13.6 Santalales 314 18.2 Dispersalinextantangiosperms 447
Contents vii
18.3 Animaldispersers 448 20Theaccumulationofangiospermdiversity 475
18.4 Historyofdispersalinangiosperms 450 20.1 Large-scalepatternsinangiosperm
18.5 Large-scaletrendsinthehistoryof diversification 475
angiospermdispersal 456 20.2 Patternsofangiospermdiversification:early
lineages 477
19Vegetationalcontextofearlyangiosperm 20.3 Patternsofangiospermdiversification:
diversification 461 eumagnoliids 483
19.1 Transitiontoangiosperm-dominated 20.4 Patternsofangiospermdiversification:
vegetation 461 monocots 486
19.2 ComponentsofEarlyCretaceous 20.5 Patternsofangiospermdiversification:
vegetation 462 eudicots 488
19.3 Vegetationduringtheearlydiversification 20.6 Angiospermevolutionandglobalchange
ofangiosperms 467 throughtheCenozoic 495
19.4 Earlyangiosperms:diversityinobscurity 469 20.7 Prospects 498
19.5 Mid-Cretaceousvegetation 471
19.6 LateCretaceousvegetationandfloristic References 501
provinces 472 Index 573

Preface
Developmentsinthestudyoffossilandlivingplantsover standard approaches to Cenozoic fossil floras in Europe,
thepastfewdecadeshavegreatlyclarifiedmanyaspectsof and pioneered in the Late Cretaceous of Scania, Sweden,
earlyangiospermevolution.Explicitphylogeneticanalyses, have now yielded diverse angiosperm flowers from many
facilitatedbythedevelopmentofcomputertechnologyand new fossil floras (mesofossil floras) discovered in Lower
based on both morphological and molecular data, have and Upper Cretaceous strata in Europe, North America,
renewed interest in the relationships of angiosperms to Asia,NewZealandandAntarctica.
other plants, the patterns of relationship among major In this book we provide a synthesis and overview of
groupsofangiosperms,andtheprocessesthathavegener- currentdataandideasonthemajorpatternsofangiosperm
ated angiosperm diversity at both microevolutionary and evolution,focusingespeciallyontheearlyevolutionofthe
macroevolutionary scales.At thesame time, arapid accu- group. Our emphasis is on the new information from
mulationofnewinformationonthestructureandbiology the fossil record that has accumulated over the past three
of many key groups of living angiosperms has catalysed decades and how this relates to recent findings on the
comparative studies and brought tolight many previously phylogenetic systematics, structure and biology of extant
unrecognised features that provide new perspectives on angiosperms.Centraltothissynthesisofthepalaeobotani-
angiospermevolution. cal data is its integration with information from living
Palaeobotanicalstudieshavealsobeencentralinrevital- plants and the presentation of previously unpublished
ising research on early angiosperm evolution and have results based on our research with Early and mid-
advanced significantly our understanding of early angio- Cretaceous fossil floras from eastern North America and
sperm history. In particular, the discovery of diverse and Portugal.
exquisitelypreserved fossil flowers andfloralorgans from Chapters1to4providethebackgroundtoinformation
the Cretaceous has yielded detailed information on the and ideas discussed in more detail later in the book.
structural and systematic diversity of early angiosperms. Chapter 1 introduces recent developments in angiosperm
These data complement the information available from palaeobotany, molecular systematics and studies of the
livingplants,andarealsoinvaluablefortestingevolution- flowers of livingplants, and brieflyconsiders some of the
aryhypothesesbasedonextanttaxaagainstpalaeobotanical waysinwhichtheseadvancesarechangingourperspective
andstratigraphicevidence.Therecognitionoffossilpollen on early angiosperm evolution. Major features of angio-
grainsinsituwithinflowershasalsoprovidednewpossibil- sperm structure and biology are also reviewed along with
ities for interpreting the record of dispersed fossil pollen. previous ideas on the origin and earlyevolution of angio-
Onlya fewdecades agothe abundant occurrence of fossil spermsandtheirflowers,aswellastheriseofangiosperms
angiosperm flowers in Cretaceous strata was unimagined, toecologicaldominance.Chapter2providesanoverviewof
buttodaythereisarichfloralrecord,muchofwhichstill the nature of the angiosperm fossil record. Chapter 3
remainstobeanalysedindetail.Thekeybreakthroughwas briefly outlines changes in palaeogeography and climate
the recognition that numerous small fossil flowers, which since the Early Cretaceous, as an introduction to the
are generally not visible to collectors in the field, can be changing world in which angiosperm diversification took
extractedfromCretaceoussedimentsbyusingbulk-sieving place.Chapter 4brieflydiscussesthestratigraphicframe-
techniques and studied with scanning electron micros- workandoccurrenceoftheangiospermfossilsconsidered
copy(SEM),andnowalsowithsynchrotronX-raymicro- in this book and provides a review of the key fossil
tomography (SXRTM). These techniques, modified from localities.
ix