prehistoric world

8/8/2019 Prehistoric World

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INFORMATION AT YOUR FINGERTIP


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PREHISTORIC

WORLD


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HOW TO USE THIS BOOK ....................................................................................4

THE AGE OF THE EARTH ........................................................................................6 Oldest minerals, rocks and meteorites The Precambrian eon Phanerozoic eon to present day Major events Previous estimatesof the age of the Earth Geological timescale

PLATE TECTONICS ..........................................................................................................8 Continental drift Seafloor spreading Another theory Some speeds Features of the Earth caused by plate movement Cross section of the Earth

ROCKS AND MINERALS .....................................................................10 Types of rock Sediments to sedimentary rock Examples of igneousrock Examples of sedimentary rock The rock cycle Examples ofMetamorphic rock

FOSSILS ..................................................................................................................................12 How fossils form The uses of fossils Before fossilization

During fossilization Fossil assemblages After fossilizationPRECAMBRIAN..............................................................................................................14 Precambrian world Stromatolites Vendian period Snowball Earth Animals of the Vendian

EARLY PALEOZOIC ERA ....................................................................................16 Paleozoic era Land animals Cambrian Ordovician Silurian The Burgess Shale Calymene Diplograptus

DEVONIAN PERIOD .................................................................................................18 The world in the Devonian period Plants The age of fish Changing atmosphere Old red sandstone Cephalaspis Eusthenopteron Ichthyostega

CARBONIFEROUS PERIOD ...............................................................................20 The world in the Carboniferous period One period or two? Formation of coal Coal forest plants Eogyrinus Meganeura Westlothiana

PERMIAN PERIOD .....................................................................................................22 The world in the Permian period Desert features Reefs Mesosaurus Pareiasaurus Dimetrodon

TRIASSIC PERIOD.......................................................................................................24 The world in the Triassic period Mesozoic era Glossopteris Meaning of the name New plant life Reasons for the mass extinction Triassic climates

TRIASSIC LIFE .................................................................................................................26 Changing plants, changing animals Hard-shelled egg: the keyto land-living Footprints What makes a dinosaur? Eoraptor Thecodontosaurus Eudimorphodon

JURASSIC PERIOD .....................................................................................................28 The world in the Jurassic period Mass extinctions Meaning of thename Typical Jurassic rocks Two Jurassic rock sequences Economicimportance Index fossils

JURASSIC LIFE................................................................................................................30 The life on a continental shelf Cryptoclidus The fossils of the lagoons Liopleurodon Pterodactylus

JURASSIC DINOSAURS................................................................. Dinosaur types A dinosaur landscape Stegosaurus Diplodocus

CRETACEOUS PERIOD.................................................................... The world in the Cretaceous period Diverse dinosaurs Meaning of the name Tylosaurus Animals of air and se Elasmosaurus Kronosaurus Arambourgiana

CRETACEOUS DINOSAURS........................................................ Saltasaurus Caudipteryx Velociraptor Tyrannosaurus Therizinosaurus Carnotaurus

CRETACEOUS LIFE................................................................................ New plants Varied habitats Iguanodon Parasaurolophus Euoplocephalus Tricerat

THE GREAT EXTINCTION .............................................................

What caused the Great Extinction? Diseases Meteorite or comet strike Changing climates Volcanic a A combination of all of these Winners and losers Repe

EARLY TERTIARY PERIOD.......................................................... The world in the early Tertiary period Plant and animal Meaning of the name Mammal names Brontotherium Hyracotherium Diatryma Oxyaena

LATE TERTIARY PERIOD............................................................... The world in the late Tertiary period Phorusrhacos Thegrass Deinotherium Synthetoceras Sivatherium Cooling climate

QUATERNARY PERIOD..................................................................

The world in the Quaternary period Causes of the Ice Agof the name Ages of the Quaternay Glacial stages Evidglaciation Smilodon Elephas Primigenius Megatherium

THE FIRST HUMAN BEINGS ................................................. When and where did human beings first appear? Why dupright? Orrorin Ardipithecus Kenyanthropus Australopithecus

THE GENUS HOMO .......................................................................... Out of the cradle The development of culture and civiliz Homo

UNCOVERING THE PREHISTORIC WORLD ......... Timeline of the History of Geology and Palaeontology Sodeductions

KEY FIGURES .........................................................................................

PALEONTOLOGY ................................................................................. Dinosaurs all around the world Finding dinos Excavatiotransportation In the lab Dino displays Museums with collections

GLOSSARY...................................................................................................

INDEX ................................................................................................................

CONTENTS

s edition published in the United States in 2006 by School Specialty Publishing, a member of the School Specialty Family.

pyright ticktock Entertainment Ltd 2005 First published in Great Britain in 2005 by ticktock Media Ltd. Printed in China.

rights reserved. No part of this book may be reproduced, stored in a central retrieval system, or transmitted in any form or by

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itten by Dougal Dixon. Special thanks to Elizabeth Wiggans.

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INTRODUCTION TO TOPIC

Time: Silurian

Size: 2 in., each branchDiet: Suspended organic particlesHabitat: Open waterInformation: Diplograptuswas acommon graptolitea floatingcolonial organism. It consisted oftwo rows of living creatures back toback, and several hangingsuspended from a gas float.

Other graptolites include

Monograptus, with a single row ofindividuals, and Didymograptus, withtwo rows arranged in a wishbone

shape. These are all valuable index

fossils for the early Paleozoic.

17

Time: SilurianSize: About 1

3

16 in.Diet: Organic particles fromsea bedHabitat: Shallow seasInformation: Calymenewasa typical trilobiteone of themost abundant of the sea-livingarthropods in the early Paleozoic.

16

E A R L YP A L E O Z O I CTIMELINE

543417 MYA

Isotelus

Period: Silurian

Diet: Buried organicmatter

Habitat: In sandy seabottoms

Information: Spade-shapedtrilobite, smooth surface,adapted for burrowing.

Cryptolithus

Period: Ordovician

Diet: Floatingorganic matter

Habitat: Open water

Information: Free-swimmingtrilobite, huge cephalonwith long spines at therear, small thorax andpygidium.

Eodiscus

Period: Cambrian

Diet: Floating organicmatter

Habitat: Open water

Information: Tiny earlytrilobite, free swimming,only two segments in thethorax, cephalon thesame size as pygidium.

Olenellus

Period: Cambrian

Diet: Organic detritus

Habitat: Shallow seabed

Information: An earlytrilobite, tiny pygidium,spines on the segments.

Meaning: From Ordovicesan old Welsh tribe.In the Ordovician period, thenorthern landmasses werebeginning to move toward oneanother. An ice age took placeat the boundary with the Silurian,450 to 440 million years ago.

ORDOVICIAN PERIOD

The most spectacular set ofCambrian fossils lies in theBurgess Shale in Canada. Theseconsist of all kinds of animals,most of which do not fit into anyestablished classification.

Burgess shale animalsMarella like a trilobite with longhorns on its head.Nectocaris like a shrimps bodywith an eels tail.Opabinia like a worm with atrunk and many pairs of paddles.Wiwaxia like a slug covered inchain mail.Hallucigenia a worm-like body

with tentacles along one side andstilts along the other.Anomalocaris a big swimmingpredator that probably huntedall these.

Meaning: From Cambria an oldname for Wales, where the originalwork was done on the lower

Paleozoic rocks.In the early Paleozoic, all of thesouthern continents, South America,Africa, India, Australia andAntarctica, were part of a singlelandmass. The northern continents,North America, Europe, and Asia,were individual landmassesscattered over the ocean.

Although we believe there wereno land animals in the earlyPaleozoic, somestrangetracefossilsfromCanada, from theCambrian period have beenfound.They were made by a soft-bodiedanimal. The animal moved alongthe damp sand of the Cambrianshoreline. The animal had flaps oneither side of its body and dugthose into the sand to pull itselfforward, creating tracks that looklike motorcycle tracks.

During the early Paleozoic era, many different kinds of hard-shelled

animals have evolved in the sea. By the end of the early Paleozoic,

however, some life was beginning to venture out of the water and

live on dry land.

EARLY PALEOZOIC ERA

LAND ANIMALS

DIPLOGRAPTUS

THE BURGESS SHALE

CAMBRIAN PERIOD

Meaning: From Silures an oldWelsh tribe.Continents were continuing tomove together. The edges of thecontinents were flooded, givinglarge areas of shallow sea overcontinental shelves. Many reefsand shallow-water organisms existedat that time. The firstland-living plants appeared.

SILURIAN PERIOD

Cephalon head shield

Thorax centralpart of body madeup of segments

Pygidium tail shield madefrom fused segments

The Burgess Shale in Canada today.

A N I M A LPROFILES

Silurian

Ordovician

Cambrian

Pridoli

LudlowWenlock

Llandovery

Bala

Dyfed

Canadian

Merioneth

St Davids

Caerfai

EarlyPaleozoicEra

See pages1213formoreinformationonINDEXFOSSILS.

The Palaeozoic era ismade up of six periods.The first three periods make upthe early Palaeozoic era. theother three are the Devonian,Carboniferous, and Permian.

PALAEOZOIC ERA

Permian 290248MYA

Carboniferous 354290 MYA

Devonian 417354MYA

earlyPalaeozoic543417MYA

See page 55formore informationon CHARLES

DOOLITTLEWALCOTTwhodiscoveredthe BurgessShale.

CALYMENE

HOW TO USE THIS BOOK

JUST THE FACTS, PREHISTORIC WORLD is a quick and easy-to-use way to look up facts

about dinosaurs, early reptiles, amphibians, and mammals. Every page is packed with names,

statistics, and key pieces of information about the history of Earth. For fast access to just the

cts, follow the tips on these pages.

TWO QUICK WAYS

TO FIND A FACT:

Look at the detailed CONTENTS list onpage 3 to find you

pic of interest.

rn to the relevantge and use the BOX HEADINGS to find theormation box you need.

Turn to the INDEXwhich starts on page60 and search for key words relating toyour research.

The index will direct you to the correct page,and where on the page to find the factyou need.

GLOSSARY A GLOSSARY of words and teused in this book begins on page

The glossary words provide additinformation to supplement the fac

the main pages.

JUST THE FACTSEach topic box presents the facts youneed in short, quick-to-read bullet points.

BOX HEADINGSLook for heading words linked to yourresearch to guide you to the right fact box.

TIMELINES

A breakdown of the names given tothe different subdivisions of time.

PICTURE CAPTIONSCaptions explain what is in the pic

ANIMAL PROFILESDifferent animals statistics arelisted here.

For fast access to facts about diffeanimals, look for the name inthe headings.

LINKS

Look for the purple links throughobook. Each link gives details of othpages where related or additionalcan be found.

ANIMAL FEATURES

A more detailed study of an animal of the time. A pictureaccompanies the information to give a better idea of what life waslike at that time.

5455 Key Figure Biographies

54

Dates: 17691839Nationality:BritishBest known for: William Smithobserved the rocks of Britain in hisrole as a canal engineer, andrealized that the same layers, orbeds, of rocks could be traced overlarge areas by using their fossils toidentify them. He eventually used

this knowledge to compile the firstever geological map, wheremainland Britain was coloredaccording to the rock types.

Key discoveries: The principleof faunal succession, in which thesame rocks can be identified bythe fossils they contain, whereverthey occur.

Dates: 17841856Nationality: BritishBest known for: William Bucklandwasa geologylecturerattheUniversityofOxford.He touredEurope and established the basic

principlesofstratigraphiccorrelationand became a scientificcelebrityon

hisdiscoveryof Megalosaurus.Hewasthe DeanofWestminsterfrom1845tohisdeathi n1857.

Keydiscoveries: Megalosaurus,the firstdinosaurtobe scientificallydescribed.

Dates:180492Nationality:British

Best knownfor: SirRichardOwenbecame

the mostimportant anatomist

ofhisday,determiningthatthewayananimallived could be

deduced byitsshape and theorgansitpossessed.However,hecould notquite grasp the newlydeveloped conceptofevolution.

Keydiscoveries: Coined thetermdinosauriain1842,toencompassthree newanimalfossilsrecentlydiscovered,from whichwe getthe namedinosaur.

KEY FIGURESWILLIAM BUCKLAND

Dates: 180982Nationality:BritishBest known for: Afterfailedattemptsatcareersinmedicine andthe church,he became a naturalist.Hisfamousvoyage on HMS Beagleallowed him toobserve and collect

examplesofflora and fauna from all

otherthe world.He builtonthealreadyexistingideasofevolutionand deduced the mechanisminvolved.

Keydiscoveries:The idea ofnaturalselectionasthe force thatdrivesevolution.

Dates: 17691832Nationality:FrenchBest known for: GeorgesCuvierwasone ofthe mostinfluentialfiguresinscience ofthe time,particularlyinthe field ofanatomy.He isregarded asthe fatherofvertebrate palaeontology.Herefused toacknowledge evolutionand resisted the popularizationofscientificknowledge.

Keydiscoveries: Classified alllivingand fossilthingsaccording

totheirsimilaritytoone another,aswe dotoday.

GEORGES CUVIER

Dates: 183199Nationality: AmericanBest known for: ProfessorofpalaeontologyatYale Universityand curatorofthe PeabodyMuseum ofNaturalHistory.Hewasa rivalofEdward DrinkerCope,and theiranimosityresulted

inthe bone wars,wheneachtried todiscovermore thantheother.

Keydiscoveries: About80newgeneraofdinosaurs,establishingthe vastnessoffossillife.

Dates: 17991847Nationality:BritishBest known for: MaryAnningwasa professionalfossilcollectorworkingfrom the beachesofDorset and Devoninthe southoEngland.She beganwork whenshe was12yearsold tosupportherfamilyafterherfatherdied.MaryAnningiscredited withfindingthe firstcomplete fossilathe age ofjust12onthe beachLyme Regis.She supplied fossilsforallthe eminentscientistsofthe day.

Keydiscoveries: The firstfullskeletonofanichthyosaurandalsoofthe firstplesiosaur.

Dates: 18801930Nationality: GermanBest known for: Alfred Wegenerwas a meteorologist, doing agreat deal of work in Greenland.

He advocated the concept ofcontinental drift, calling itcontinental displacementwhen he first lectured on it in1912, although he could notthink of a mechanism that wouldaccount for the phenomenon.He died in an accident on theGreenland ice cap.

Key discoveries: Proposingcontinental drift as a seriousscientific idea.

WILLIAM SMITH

CHARLES DARWIN

Dates: 184097Nationality: AmericanBest known for: Edward DrinkerCope was one of the firstvertebrate palaeontologists inAmerica and was affiliated withThe Academy of Natural Sciencesin Philadelphia. His arrogancedrove him to fall out with OthnielCharles Marsh, instigating thebone wars. This event

stimulated the discovery ofdinosaurs, but drove moremethodical workers awayfrom the science.

Key discoveries: About 65 newdinosaur genera.

MARY ANNING

Seepage3031ICHTHYOSAURS

OTHNIEL CHARLESMARSH

SIR RICHARD OWEN

ALFRED WEGENER

EDWARD DRINKERCOPE

5352

610425BCPhilosophers Thales,Anaximander, Pythagoras,Xenophanes, and Herodotus recognizethat fossils show that the distribution ofland and sea was once dif ferent.

78BCPliny the Elder writes the f irstnatural history encyclopaedia.

cAD1000Al-Beruni (9731050)observes that dif ferent grades ofsediment is deposited by dif ferentstrengths of river currentsan earlyobservation of sedimentology. He alsoputs precious minerals intogeological context.

1020Avicenna (or Sina)observes the work of erosion.

1056Albertus Magnus publishesa book on minerals.

1500 Leonardo daVinci states that

fossils are remains of animals andtheir enclosing rocks must have beenlif ted from below sea level.

1542Leonhart Fuchs publishes acataloge of 500 plant species.

1546Georgius Agricola (bornGeorge Bauer, 14941555), Fatherof mineralogy, classif ies minerals bytheir crystal shape and composition.Publishes an analysis of ore bodies.

1585Michele Mercati opens the f irstgeological museum.

1596Dutch cartographer AbrahamOrtelius f irst suggests continental drif t.

1600William Gilbert, Elizabeth Isphysician, describes the Earthsmagnetism.

1616Italian philosopher LucilioVanini f irst to suggest humansdescended from apes. He was

executed for this belief.

1641 Lawyer Isaac LaPeyrre suggests thatpeople existed before

Adam and Eve. Hisideas were only

published afterhis death.

1658JesuitmissionaryMartinoMartinishowsthatChinesehistorypredatestheabove.Nobodytakesnotice.

1668 RobertHookeclaimsthatEarthsmovements, and not the biblical Flood,moved fossils to dry land.

1669 Nicolaus Steno (born NeilsStensen, 163886) establishes thelaws of stratigraphy, which state thatrock beds laid down horizontally,stacked on one another, andsubsequently contorted.

1679 ScandinavianhistorianOlofRudbecktriestodatesedimentaryrocks.

1688 The Ashmolean Museum opensin Oxfordthe worlds f irst public

museum.

1715 Edmund Halley suggests theage of the Earth can be calc ulatedfrom the salinity of the seas.

1735 Linnaeus establishes thebinomial classif ication of living things.

1745 Mikhail Vasilevich Lomonosov(171165) recognizes that ancientgeological processes would have beensimilar to todays, in anticipation of

James Hutton (see 1795 ).

1749 Georges-Louis Leclerc deBuffon speculates that the planetsformed by a comet crashing into thesun. The people in power force him toretract it.

1751 Diderot and dAlembert publishthe f irst encyclopaediawith areliance on factual information ratherthan on traditional beliefs.

1760 Giovanni Arduino classif ies thegeological column Primary: with nofossils, Secondary: deformed and withfossils, Tertiary: horizontal and withfossils, and Quaternary: loose sandsand gravels over the rest. This was a

rough basis of modern classif ication.

1766 TorbernOlafBergman(17351784)seesthatdif ferentrock

typeswereformedatdifferenttimesandappreciatestheorganicoriginoffossils.

1768James Cooks voyage brings anawareness of the range of plants andanimals around the world to theUnited Kingdom.

1771Joseph Priestley discoversoxygen and shows its importance to

life.

1778 Buffon puts the age of the Earthat 74,832 years.

1789 French researcher AntoineLavoisier interprets dif ferentsedimentary rocks as showing di fferentsea levels in the past.

1795James Hutton, the Founder ofmodern geology, sees geologicalprocesses as a cycle, with nobeginning and no end.

1799Alexander von Humboldtnames the Jurassic system.

1799 British surveyor William Smithproduces the f irst geological map,establishing the importance of fossilsto define rocks and times.

1804 Cuvier acknowledges that fossilanimals are older than can beexplained by the Bible and suggestsprevious cycles of creation anddestruction.

TIMELINE OF THE HISTORY OF GEOLOGY AND PALAEONTOLOGY

1824 Buckland describes the f irstdinosaur.

1830 Charles Lyell publishes hisinf luentialPrinciples ofGeology.

1837 Charles Darwin uses naturalselection to explain evolution, but theidea is not published until 1859.

1837 Swiss scientist Louis Agassizdetects the Ice Age.

1841William Smiths nephew, JohnPhillips, names the geological erasPalaeozoic, Mesozoic, and Cenozoic.

1842 Sir Richard Owen invents theterm dinosaur.

1848 Science magazine establishedby the American Association for the

Advancement of Science.

1866Austrian monk Gregor Mendelestablishes the laws of heredity. His

work remains unknown until about1900.

1871 Darwin publishes TheDescentofMan.

1894 Eugene Debois describesPithecanthus erectus (nowHomoerectus) as the missing link betweenhumans and apes.

1902Walter Sutton discovers thechromosometheoryofinheritance.

1902 Physicist Ernest Rutherfordshows that radioactivity means that

the Earth is older than Kelvin said.

1912Alfred Wegener proposescontinental drif t.

1927 Belgian priest GeorgesLematre proposes that the universebegan with the explosion of aprimeval atoma forerunner of theBig Bang theory.

1934AmericangeologistCharlesF.RichterestablishestheRichterscaleformeasuringearthquakes.

1946 Geologist Reg Sprigg f inds theoldest fossils of multicellular organismsin Australia.

1953 Stanley Miller and Harold Ureycombine the gases of the Earth s initialatmosphere and form the chemicalsfrom which living things are made.

1953James Watson and FrancisCrick determine the molecularstructure of DNA.

1953 Fiesel Houtermans and ClairePatterson use radiometric dating todate the Earth at 4.5 billion years old.

1956 Keith Runcorn notes polarwandering based on paleomagneticstudies.

1961AmateurmeteorologistGSCallandernotestheriseingreenhousegasesintheatmosphereandwarnsofaglobalwarming.

1963 Fred Vine and DrummondMatthews discover seafloor spreading.This leads to the establishment of platetectonics.

1964Arno Penzias and RobertWilson detect cosmic radiation anduse it to confirm the Big Bang Theory.

1966Willi Hennig developscladistics , a new approach to studyingevolutionary relationships.

1969 Moon rock samples prove thatthe moon the same age as the Earth.

1972 Stephen Jay Gould and NilesEldredge develop the theory ofpunctuated equilibrium, meaning thatevolution takes place in short bursts.

1974John Ostrom resurrects theidea that birds evolved from dinosaursan idea that had been dormant fora century.

1980 Louis and Walter Alvarez putforward the asteroid impact theory ofdinosaur extinction.

1985 Discovery by scientists of theBritish Antarctic Survey of thedepletion of ozone in the upperatmosphere.

1988 Hottest northern hemispheresummer on record brings publicawareness of global warming.

1991 Chicxulub crater in Yucatan ispinpointed as the site of the impactthat may have caused the dinosaurextinction.

1992Joe Kirschvink suggests thesnowball Earththeorythat the Earth

was covered by ice during thePrecambrian.

The history of life on Earth is pieced together through the detailed accumulation of

knowledge gained over the centuries by visionary and hard-working scientists.

Alist such as this cannot be exhaust ive. There are many others whose contributions were as

great but just did not make it on to this page because of lack of room.

UNCOVERING THEPREHISTORIC WORLD

S O M E W R O N GDEDUCTIONS

1650 Irish ArchbishopUssher calculates date ofCreation at 4004 BC.This is widely accepted.

1780 Abraham GottlobWerner (17491817)theorizes that all rocks areformed in ancient oceans.He is wrong but greatlyinfluential.

1800 Lamarck proposesa theory of evolution.It suggested that traits thatare acquired in life canbe passed on to the nextgeneration. This is nolonger accepted since thegeneral acceptance ofDarwins theory of naturalselection.

1862 Lord Kelvin suggeststhat the Earth is 20400million years old, basedon rates of cooling.

Calcitea common mineral

Darwin studied thefeaturesof different speciesto develop

histheoryof evolution.Alfred Wegener

Crickand Watson

TheEarthsmagnetism

JamesCook

A50,000-year-oldcratershowsthattheEarthis stillbeingbombardedbymeteors.

5253 Uncovering the Prehistoric World Timeline

See pages 1213 for moreinformation on index fossils.

Isotelus


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Precambrian eon coversee eras and over 4,000ion years. However, duringperiod, primitive lifeformse only starting to develop, it wasnt until later that life

truly began to take shape aswe know it.

Proterozoic 2,500543 MYA

Archaean 3,8002,500 MYA

Hadean 4,5003,800 MYA

THE PRECAMBRIAN EON 4,500543 MYA

This is what the surface of the Earth may have looked likewhe it was still forming in the Hadean era.

The oldest minerals 4.3billion years old. They werefound in much youngersedimentary rocks in Australia.

The oldest rocks 4.03billion years old found inthe Great Slave Lake innorthwestern Canada (shown

below). These are metamorphicrocks and are formed fromrocks that already existed andmust have been older.

The oldest meteorites 4.6billion years ago. They areassumed to have formed at thesame time as Earth.

OLDEST MINERALS, ROCKS, AND METEORITES

About 5 or 6 thousand yby the dates in the Bible anaccepted until about 150 y

2540 million years L1862. He based his calculathe Earth would take to cootemperature assuming thatand molten. He did not knowRadioactivity continues to gthe Earth cools much more

Irish Geologist Samuel H1878 suggested that the aestimated by measuring thesedimentary rocks.

27.6 million years Wa

18.3 million years Solhe and Walcott were influen

704 million years Goo 96 million years John

He was working on the ratesalt in the ocean.

PREVIOUS ESTIMTHE AGE OF TH

The Phanerozoic eeras: the PaleozoiGREEN, the Meshighlighted in PUCenozoic, highlighEach one of these subdivided into difnoted. Although theon is only 543 mcovers the period wadvances on Earth

PHANEROZTO PRESE

We can look at

radioactive minerals

in rocks.

Radioactive mineralschange at a regular rateover time. By looking atthe amount of radioactivemineral that has changed,we can figure out howlong the changes have beengoing on, which providesthe length of time sincethe mineral was formed.

HOW DO WEKNOW?

When the geolois shown verticadivision is alwayand the youngepresent day, is a

This reflects thewhich sedimentlaid down (see

GEOLOGICSCA

The Reptiles FlourishBetween the Perm ian and Triassicperiods, there was another massextinction. This brought about a spurtin the development of lifeform. Thefirst dinosaurs appeared on Earth.

The First ReptilesIn the Carboniferous period,life on land was fully established.The coal forests are filled with giantinsects and the first reptiles.The forests eventually formedthe coal we use as fuel today.

The Age of MammalsAfter nearly all of life is wiped out bythe Great Extinction, the Early Tertiaryperiod sees life on Earth taking newdirection. Gone are the dinosaurs andgreat pterosaurs that ruled the sky,new creatures that graze on thenewly developing grass and plantsthrive during this time.

Human Beings First AppearHuman beings first appeared about200,000 years ago. Earth begins tolook more and more like it does now.

The Great ExtinctionAt the end of the Cretaceous period,a cataclysmic event occuredthat wiped out all the dinosaurs,pterosaurs, and sea reptiles.This cleared the way for the firstmammals.

t Signs of Life on Lande early Paleozoic period, life wasominantly sea-based. Hard-shelledals were evolving at this time. Bynd of the period, life was startingnture onto the land.

The Earth is

about 4.6 billion

years old.

During that time, there

have been extreme

changes in layout of the

land and the oceans, as well

as vast differences in the kinds of life that have

walked on Earths land, flew in its sky, and

swam in its seas. While everything looks to be

stable in our eyes, the Earth is constantlychanging, continents are moving, and life

continues to change.

THE AGE OFTHE EARTH

The Age of Dinosaurs BeginsDinosaurs evolved in the late Triassicperiod and ruled the Earth until theend of the Cretaceous period. As thecontinents moved apart, newer andmore fantastic dinosaurs evolved onthe separate continents.

rly Paleozoic 543417 Devonian 417354 Carboniferous 354290 Permian 290248 Triassic 248206 Jurassic 206144 Cretaceous 14465 Tertiary 651.75 Quaternary 1.75present


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German geologist O.W. Hilgenbergand British physicist P.A.M .Dirac (inthe 1930s) and British geologistH.G. Owen (in the 1960s)suggested that the continents weremoving apart because the Earth wasexpanding. Few scientists accept thisidea today.

ANOTHER THEORY

k at a map of the world.shape of the east coast ofth America fits into the westst of Africa. People in the paste noticed this as well.

1620, Francis Bacon noticed thelarity but did not suggest a reason.

668, P. Placet suggested thatBiblical Flood had forced thetinents apart.

855, Antonio Snider drewps to illustrate how the world used

to be, but nobody took him seriously.

In 1908, F.B. Taylor tried toexplain it, along with the formationof mountains, by a movement ofcontinents southwards from theNorth Pole.

In 1915, Alfred Wegener iscredited with beginning the seriousscientific discussion of thephenomenon.

f the continents are moving apart,hen something must be happeningo the ocean floor between them.cientists started discovering thisuring the late-20th century.

he crew of the US Atlantis, in 1947,oticed that sediment was thin onhe floor of the Atlantic Ocean. Thismeant that part of the ocean floorwas younger than other parts.

Various oceanographic surveys

n the 1950s observed oceanicdges, particularly the one in themiddle of the Atlantic.

American geologist Harry Hessoted in 1960 that the sediment

was thinner over the ocean ridgeshan in the deeper waters at eachide. The ridges were youngerhan the rest of the ocean.

ritish geophysicists Fred Vine

and Drummond Matthews found,

in 1963, that the rocks of theridges in the Atlantic Ocean werearranged in strips, magnetized indifferent directions. They hadformed at different times whenthe Earths magnetic field waspointing in different directions.

Canadian geologist LawrenceMorley made the sameobservations in the Pacific Oceanin 1963.

This showed that the oceans were

growing larger at their ridges.Volcanic activity formed newseafloor there, and this movedaway from the ridge as evennewer material formedin between. Hess proposed thename seafloor spreading.

Combined with continental drift,these two theories make up platetectonics.

The surface of the globe is madeup of plates, like the panelsof a soccer ball. Each plate isgrowing from a seam along oneside and moving along beneaththe next plate at the seam onthe other side. The continentsare carried by in these plates.

As the continents move about,they occasionally crash into oneanother. This causes the edge tocrumple up, forming mountains;

fusing together to form biggercontinents; or splitting apart asnew seams grow beneath them.

All the continents consist ofancient cores, that have beenthere for billions of years, andsurrounded by progressivelyyounger ranges of mountains.

Movement of plates in NorthAtlantic

68 in per year. This is

typical.

Movement of plates in Pacific 1

58 in per year. This is the

fastest.

In 1492, Christopher Columbus sailed across the Atlantic and became the first European recorded to

have set foot in North America. His voyage took him 70 days. Today, the Atlantic Ocean is over 30

feet wider now than it was 500 years ago. The plate tectonics theory states that the Earth is made up

about 30 plates that sit on a layer of molten rock. the plates move about 4 inches a year. While that

y not seem like a lot, combine that small amount with billions of years, and there is a large change.

PLATE TECTONICS

SEAFLOOR SPREADING

CONTINENTAL DRIFT

SOME SPEEDS

CROSS SECTION OF THE EARTH

The Azores are a group of islands that lie on the Mid-Atlantic ridge, whichwere formed by molten rock as the plates move away from each other.

Eurasian plate

Anatolian plate

Arabian plateAfrican plate

Antartic plate

Indian-Australianplate

Philippineplate

Somali sub-plate

North American plate

Caribbeanplate

SouthAmericanplate

Nazcaplate

Cocos plate

Pacific plate

Mid-Atlantic Ridge

Where the two halvesof the Atlantic Oceanare growing apart.

Australia

A continent beingcarried north as the

plate moves.

East AfricanRift Valley

Where a continent isbeginning to split apart.

Red Sea

Where the continentis already split.

Mediterranean Sea

Where two plates are sliding next to oneanother, creating islands, mountains, and

volcanoes.

Ur

T

coto

d

AndesMountains

formed as anocean plate is

forced beneath acontinental

plate.

Aleutian Islands

Arc of islandsformed where oneocean plate slidesbeneath another.

Center

3950 miles down.

Inner core

solid iron upper boundary 3200 miles.

Outer core

liquid iron upper boundary 1800 miles.

Mantle

mostly solid stone upper bounda3 to 6 miles beneath the ocean a56 miles beneath the continents.

Crust

solid stone. The upper 60 miles of and topmost mantel is called the lithos

forming the plates. The next 60 miles ofmantel is called the asthenosphere, which

mobile layer on which the plates move.

FEATURES OF THE EARTH CAUSED BY PLATE MOVEMEN

See page 55ALFREDWEGENER.


7/36

Marble (thermas limestone is igneous activity.

Slate (regionalmountain-buildion sedimentary shale. It splits eof weakness.

Schist (regionamore intense mactivities. New mformed along tw

Gneiss (regionin the extreme dmountains and obvious crystals

EXAMPMETAMORP

Granite (intrusive) has bigcrystals created by cooling slowly.It is light in color because of thehigh proportion of silica in the

minerals. It comes from deep inmountain ranges.

Gabbro (intrusive) has bigcrystals. It is dark in color becauseof the low proportion of silica inthe minerals. It is found deep inmountain ranges and the crust ofthe ocean.

Dolerite (intrusive) is coolednear the surface, so it has smallercrystals that need to be seen with

a microscope.

Basalt (extrusive) is very fine-grained due to rapid cooling. It issolidified lava flow. It has a blackcolor because of the lowproportion of silica minerals. Itcomes from freely-flowingvolcanoes.

Andesite (extrusive) It isvery fine-grained due to rapidcooling. It is solidified lava flow. Ithas a pale color because of the

high proportion of silica minerals.It is found in explosive volcanoes,such as Mount Saint Helens and

Vesuvius.

EXAMPLES OF IGNEOUS ROCK

The material of the Earthscrust is constantly changing,usually through plate-tectonicactivity.

Rocks melt and are solidified asigneous rocks. These may breakdown when exposed and becomesedimentary rocks or may be

changed into metamorphic rocks.These then may break downagain. This is known as therock cycle.

Conglomerate (clastic) is coarse,like a solidified pebble bed, and isformed from shingle beaches.

Sandstone (clastic) is medium-grained and formed from sandaccumulated in river beds or deserts.

Shale (clastic) is fine-grained andformed from mud laid down in verythin beds in a river, lake, or sea.

Mudstone (clastic) is fine-grainedlike shale, but does not split intoeven beds.

Clay (clastic) is so fine-grained thatit is difficult to see the fragments,even with a microscope. It is usuallyformed in still waters, such as lakes.

Coal (biogenic) is formed asvegetable material piles up in bedsand does not rot away.

Halite/rock salt (chemical) isformed as salty waters dry out inlakes or sheltered bays.

Limestone can be clastic, frompreviously-formed limestone;biogenic, from seashells or coral

reefs; or chemical, from dissolvedcalcite in sea water.

Sedimentary rocks afor fossil formation.

re are three types of rock, these form in different ways.

eous rock is formed whenten material from inside theth cools and solidifies. Usuallyminerals can be seen as distincttals in igneous rock. There are

types of igneous rock:ntrusive formed under theace of the Earth. This tends tooarse with big crystals.

2. Extrusive formed on thesurface of the Earth from coolingmolten lava. This is usually fine, withcrystals that cannot be seen with thenaked eye.

Sedimentary rock is formed fromfragments that are laid down aslayers. There are three types ofsedimentary rock:

1. Clastic formed from pieces ofrock that have broken from rocksthat already exist.

2. Biogenic formed from materialgathered by living things.

3. Chemical formed as mineralscrystallize out of seawater.

Metamorphic rock.is the result ofexisting rocks being heated and compressed by Earths movements

that cause their minerals to change.The original rock does not meltotherwise the result would be anigneous rock. There are two types ofmetamorphic rock:

1. Thermal metamorphic formedprincipally by the action of heat.

2. Regional metamorphic formed principally by the actionof pressure.

diments pile up in beds onbottom of a river, sea, ore, or even in a desert.

he weight of the sediments onop compress those below.

Ground water percolates through

he beds, depositing minerals as

goes, cementing the

edimentary particles together.

he result is a solid mass, called

edimentary rock.

ny undisturbed area, the oldestimentary bed is at the bottom,ch is why it appears at thetom of a geological time scalegram.

The crust of the Earth is made up of minerals. Usually, minerals form crystals of a particular

shape, but sometimes these crystals are distorted or too small to see. When differ ent minerals

form together, the result is rock.

ROCKS AND MINERALS

THE ROCK CYCLE

EXAMPLES OF SEDIMENTARY ROCK

SEDIMENTS TOEDIMENTARY ROCK

TYPES OF ROCK

Metamorphic rock

Extrusive rock

Sedimentary rock

Conglomerate

Gne

Intrusive rock

Volcanic ash settles in sediment

Layer upon layer ofrock and sediment form

Rivers carryweathered rock

to the sea

Layers harden to formsedimentary rock

Igneous rockand sedimentaryrock change to

metamorphic rock

Heat andpressure

Lithfication

MeltingMetamorphic andsedimentary rock melt

to form magma(molten rock)

Magma isforced up to

Earthssurface

Magma is calledlava at Earths

surface

Lavacools

Heat andpressure

Heat andpressure

Rocks reachEarthssurface

Rocks on Earths surface areeroded by weathering



Lava becomes solid

igneous rock

Granite


8/36

Apart from showing us the historyof life on Earth, fossils can beused for a number of purposes.

Index fossils Some animals orplants only existed for a shortperiod of time. When the fossils ofthose animals are found in rock,

the rock must have formed duringthat time. By observing thepresence of fossils with overlappingtime periods, the date of that rockcan be more precise.

Facies fossil Some animals orplants can only live under specificenvironmental conditions. Whenthe fossils of these creatures arefound, the rocks in which they areentombed must have formed underthese conditions. Facies fossils areimportant to oil geologists whoare looking for rocks that formedunder the right conditions toproduce oil.

THE USES OF FOSSILS

Fossils are not usually found individually. Many are fotogether as groups called assemblages.

Life assemblage This occurs when the fossils reflect hthe animals and plants lived. In a life assemblage, themolluscs are still joined together and attached animalsare in their growth positions. It is as if the whole commjust dropped dead on the spot. This is very valuable in how the animals lived.

Death assemblage This occurs when the dead animalare carried by currents and end up all jumbled togetheidentify a death assemblage by the fact that bivalve shapart and may be aligned in the direction of the currenskeletons are disarticulated and scattered, and fossils fenvironments are mixed up with them.

For an organism to become a fossilit must be buried rapidly insediment. This will ensure thatnone of the taphonomic effectswill take place.

This is why most of the fossilsfound are of animals that live inthe water, where sediment is

accumulating, and why fossils ofland-living animals are very rare.

The remains are then affectedin various ways, producing thedifferent fossil types.

The process that takes place as thesediment becomes sedimentaryrock, is known as diagenesis.

Once a fossil is formed, it lies

deep beneath the surface ofthe Earth, maybe severalmiles down.It must be brought to thesurface to be found. Thisusually happens if thesedimentary rocks that containit are caught up in mountain-building processes through theactions of plate tectonics. Therocks may be twisted and

crushed up so mu

end up as mountabove sea level. the rain then bredown, forming nefor clastic sedime

The fossil-bearthen be exposed

sils form in different waysd can be classed on howch of the original creatureeft.

Organisms preserved in theirntirety. These are very rare andnclude things like insectsntombed in amber.

The hard parts of living thingsreserved unaltered, such asharks teeth in Tertiary sediments.

Only some of the original substancef the living thing left. Leaves canreak down leaving a thin film ofhe original carbon in the shape ofhe leaf. This produces coal.

4. Petrified living things. The originalorganic substance is replacedmolecule by molecule to producea fossil with the original structurebut made entirely of mineral.Petrified wood is created by thisprocess.

5. Mould. This is a hole left inthe rock when all the originalorganic material has decayedaway. A special kind of mouldforms from the hollow betweenthe shells of a bivalve seashell.

6. Cast. When a mould (see E) is

filled by minerals deposited byground water, the result is a lumpin the shape of the original body,but does not have the internalstructure. A cast can form in thespace between the valves ofseashells, showing us the shapeof the interior of the shells.

7. Trace fossils. Sometimes nothingof the original organism is left just its burrows or the marks thatit made, showing us how it livedbut not what it looked like.Dinosaur footprints are importanttrace fossils.

We know that animals and plants existed long ago on the Earth. They have left their remains

behind as fossils. These may be parts of the original organisms or traces, such as footprints,

that they left behind. Fossils give unique insight into what kinds of life lived millions of

ars ago. How they grew, if and how they cared for their young, and what they are are many of the

ngs we have discovered from studying fossils.

FOSSILS

AFTER FOSSILIZATION

FOSSIL ASSEMBLAGESDURING FOSSILIZATION

HOW FOSSILS FORM

ny things can happen to an organism before it is fossilized.

t can be eaten, or partially eaten, by other animals.

t may rot away.

It may break down under the influence of the weather.

This is why it is very unlikely for any individual organism to be preservedas a fossil. Activity before fossilization is known as taphonomy.

BEFORE FOSSILIZATION

Petrified wood

Finding dinosaur fossils.

Death assemblage (left) and life assemblage

See pagePLATETECHTO


9/36

The Precambrian lasts over85 percent of the Earthshistory.

During the Precambrian, thecontinents were very small,with the Earth almost

completely covered by water.

VIDENCE OF LIFETIMELINE

5 million yearsns of where microbes may haveen into newly erupted basaltws on the sea bed.

0 million yearsearliest known multicelled

anisms, like sea anemones comem the Mackenzie MountainsCanada.

8 billion yearsdence of life can be found in theer Springs Chert in Australia.

billion yearsnflint chert microfossils showdence of life in Canada.

465 billion yearssible lifeforms in microfossils inApex Chert in Australia.

5 billion yearsrofossils in Swaziland show

ns of life. (The chert in whichst of these are found is a glassymentary rock made of silica) The earliest good fossils

discovered are of stromatolites.

These occur when microscopicfilaments of algae or bacteriaattract particles of sediment andform a mat. Other mats build up onthis to form a dome-like structure.The oldest stromatolites are 3.5billion years old.

Today, they are found in theRed Sea and around Australia insheltered salty bays where there

are no other living things to disturbtheir growth.

The first living things were molecules that couldreproduce themselves from the chemicals aroundthem. Eventually, they became single-celledorganisms, first with simple prokaryotic cells, and

then with more complex eukaryotic cells. The lattereventually developed into multi-celled types. Thecells formed tissues that built up intoindividual organs. Amongs the earliestmulti-celled organisms were strange

soft-bodied organisms from theVendian period in Australia andof England. Theseinclude Spriggina,which resembled asegmented worm,and Charnodiscus,a feather-likeanimal found on theseafloor.

It is possible that between 750 and580 million years ago, the Earth wasentirely frozen. As this was just beforemany-celled animals appeared, it ispossible that the return to moretemperate climates, after such a drasticevent, spurred the burst in evolution.

Evidence Glaciated rocks in Australia and

other continents from that timeformed at sea level near the equator.

Limestones formed at that timeshow evidence that they would have

formed in very cold wate

Lack of oxygen in the ais shown by the mineralthat time. This would coif cold conditions killed all life.

very end of theoproterozoic is known asVendian. Fossils of multi-ed animals are knownm this period, but none withard shell.

ny scientists like to include thedian in the Paleozoic eraer than the Precambrian.

During much of Precambrian, life was developing from mere

molecules that had the ability to reproduce, such as viruses, through

the formation of single cells, such as bacteria, to creatures that were

made up of many cells. Some of these creatures were the precursors of

todays life forms.

PRECAMBRIAN

VENDIAN PERIOD

ANIMALS OF THE VENDIAN

SNOWBALL EARTH

PRECAMBRIAN WORLD

STROMATOLITES

What the Earthmay have lookedlike 750-580million years ago.

CharnodiscusSprigginaModern stromatolites in Australia.A fossilized stromatolite

R E C A M B R I A N,500543 MYA)TIMELINE

Proterozoic

Archaean

Hadean

Neoproterozoic

Mesoproterozoic

Paleoproterozoic

PANTHALASSIC OCEAN

PANAFRICAN OCEAN

Precambrian


10/36

Time: SilurianSize: 2 in., each branchDiet: Suspended organic particlesHabitat: Open waterInformation: Diplograptuswas acommon graptolitea floatingcolonial organism. It consisted oftwo rows of living creatures back toback, and several hangingsuspended from a gas float.

Other graptolites includeMonograptus, with a single row ofindividuals, and Didymograptus, withtwo rows arranged in a wishbone

shape. These are all valuable indexfossils for the early Paleozoic.

Time: SilurianSize: About 1

3

16 in.Diet: Organic particles fromsea bedHabitat: Shallow seasInformation: Calymenewasa typical trilobiteone of themost abundant of the sea-livingarthropods in the early Paleozoic.

E A R L YP A L E O Z O I CTIMELINE

3417 MYA

Isotelus

Period: Silurian

Diet: Buried orgmatter

Habitat: In sandbottoms

Information: Sptrilobite, smoothadapted for bu

Cryptolithus

Period: Ordovic

Diet: Floatingorganic matter

Habitat: Open w

Information: Fretrilobite, huge cwith long spinerear, small thorpygidium.

Eodiscus

Period: Cambri

Diet: Floating omatter

Habitat: Open w

Information: Tintrilobite, free sw

only two segmethorax, cephalosame size as py

Olenellus

Period: Cambri

Diet: Organic d

Habitat: Shallowbed

Information: Antrilobite, tiny pyspines on the se

Meaning: From Ordovicesan old Welsh tribe.In the Ordovician period, thenorthern landmasses werebeginning to move toward oneanother. An ice age took placeat the boundary with the Silurian,450 to 440 million years ago.

ORDOVICIAN PERIOD

The most spectacular set ofCambrian fossils lies in theBurgess Shale in Canada. Theseconsist of all kinds of animals,most of which do not fit into anyestablished classification.

Burgess shale animalsMarella like a trilobite with longhorns on its head.Nectocaris like a shrimps bodywith an eels tail.Opabinia like a worm with atrunk and many pairs of paddles.Wiwaxia like a slug covered inchain mail.Hallucigenia a worm-like body

with tentacles along one side andstilts along the other.Anomalocaris a big swimmingpredator that probably huntedall these.

Meaning: From Cambria an oldname for Wales, where the originalwork was done on the lowerPaleozoic rocks.In the early Paleozoic, all of thesouthern continents, South America,Africa, India, Australia andAntarctica, were part of a singlelandmass. The northern continents,North America, Europe, and Asia,were individual landmassesscattered over the ocean.

hough we believe there wereand animals in the early

eozoic, some strange tracesils from Canada, from thembrian period have beennd.y were made by a soft-bodiedmal. The animal moved alongdamp sand of the Cambrianreline. The animal had flaps oner side of its body and dugse into the sand to pull itselfward, creating tracks that lookmotorcycle tracks.

During the early Paleozoic era, many different kinds of hard-shelled

animals have evolved in the sea. By the end of the early Paleozoic,

however, some life was beginning to venture out of the water and

live on dry land.

EARLY PALEOZOIC ERA

LAND ANIMALS

DIPLOGRAPTUS

THE BURGESS SHALE

CAMBRIAN PERIOD

Meaning: From Silures an oldWelsh tribe.Continents were continuing tomove together. The edges of thecontinents were flooded, givinglarge areas of shallow sea overcontinental shelves. Many reefs

and shallow-water organisms existedat that time. The firstland-living plants appeared.

SILURIAN PERIOD

Cephalon head shield

Thorax centralpart of body madeup of segments

Pygidium tail shield madefrom fused segments

The Burgess Shale in Canada today.

A N IPROF

Silurian

Ordovician

Cambrian

Pridoli

Ludlow

Wenlock

Llandovery

Bala

Dyfed

Canadian

Merioneth

St Davids

Caerfai

See pages 1213 for moreinformation on INDEXFOSSILS.

e Palaeozoic era isade up of six periods.

first three periods make upearly Palaeozoic era. theer three are the Devonian,boniferous, and Permian.

PALAEOZOIC ERA

Permian 290248 MYA

arboniferous 354290 MYA

Devonian 417354 MYA

rly Palaeozoic 543417 MYA

See page 55 formore information on CHARLES

DOOLITTLEWALCOTT whodiscovered the Burgess Shale.

CALYMENE


11/36

Dunkleosteus

Period: Late Dev

Diet: Other fish

Habitat: Open

Information: A form of the armfishone of theof the time.

Cladoselache

Period: Late Dev

Diet: Other fish

Habitat: Open

Information: Anshark, very simmodern formssharks has not much over the y

Bothriolepis

Period: Early D

Diet: Organic d

Habitat: Lakes

Information: A armored fish, cDevonian perioarmored jointed

fins.Climatius

Period: Early D

Diet: Other fish

Habitat: River m

Information: Oso-called spiny with heavy scaldouble row of fits belly.

The atmosphere during the early

part of Earths history was a toxicmix of poisonous gases that no

animal could breathe. By the

Devonian it had changed, withoxygen being added to the

atmosphere by plant life in the

water and on land. This made itpossible for the land to be habitated.

Atmosphere at the Earths beginning Precambrian atmosphere Devonian atmosphere

CHANGING ATMOSPHERE

Meaning: Fish-roofTime: Late DevonianSize: 3 ft. 3 in.Diet: Fish and insectsHabitat: ShorelinesInformation: One of the earliest of amphibians.Ichthyostegastill had a fishs skull and tail. Its hindlimbs had eight toesthe standard five-toed pattern had not yet evolved.

This type of rockis typical of theDevonian period.Formed from rivergravels and desertsandstones, itturned red throughoxidation of iron init by exposure to air.

The Devonian period is named after the county ofDevon in the United Kingdom, where many rocks ofthis period have been found.During this time, the continents were beginning to movetogether. The land that will become Europe and North

America collided, forming a single continent, called OldRed Sandstone, with an enormous mountain range upbetween the two. The remains of this mountain range arefound in the Scottish and Norwegian Highlands and partof the Appalachians in North America.

earliest land plants werehing but a stem that

ported a reproductive body.the end of the Devonian,e were forests of horsetailsferns.

During this period, animals began to leave the water and live on

land. In the previous Silurian period, land plants first appeared. The

first land-living animals were insects, living in this vegetation.

Then came the vertebrates in transitional forms between fish and amphibians.

They would have been attracted by the new food supplies on land, or may

have taken refuge from the ferocious fish and sea scorpions that lived in the

water.

DEVONIAN PERIOD

Meaning: Properly strong finTime: Late DevonianSize: 3 ft. 3 in.Diet: Other fishHabitat: ShorelinesInformation: A fish that shows adaptationsto life on land. Its fins were in pairs and had bonesand muscles, allowing it to move over dry surfaces.A lung enabled it to breathe air.

Meaning: Head spikeTime: Late Silurian Early DevonianSize: 50 cm (19 ft 5 in).Diet: Organic detritus.Habitat: Shallow water.Information: This early fish hadno jaws, just a sucker to allow it toscoop up food from the sea bed.

PLANTS

E V O N I A NTIMELINE

7354 MYA

ough fish had already evolved,y did not become importantl the Devonian, also known asAge of Fish.

THE AGE OF FISH

THE WORLD IN THE DEVONIAN PERIOD

A N IPROF

OLD RED SANDSTONE

Famennian

Frasnian

Givetian

Eifelian

Emsian

Pragian

Lochkovian

D3

D2

D1

CO2 75%

H2 10%

N 12%Other 3%

CO2 10%

N 7 5% N 7 5%

O2 25%

Seepages 1011

for moreinformation on

TYPES OFROCK.

Other15%

CEPHALASPIS

EUSTHENOPTERON

ICHTHYOSTEGA

GONDWANARHEIC OCEAN

EURAMERICA

Northern Appalachians

Early Devonian


12/36

Lepidodendron a club mossthat grew up to 100 ft. high. Itconsisted of a straight trunk thatbranched dichotomously (into twoequal branches, then into twoagain) with long strap-shapedleaves. Trunk covered in diamond-

shaped leaf scars.Sigillaria a club moss similarto Lepidodendronbut with leafscars arranged in parallel rows.Calamites horsetails as big as7 feet tall. Grew as reed beds inshallow water.

Cordaites a primitive relativeof the conifers that grew onslightly drier ground. Variousferns formed undergrowth andcreeping up the trunks.

Hylonomus

Period: LateCarboniferous

Diet: Insects

Habitat: In the coal forest tree

Information: An elike a modern l

Diplovertebron


Diet: Insects anamphibians

Habitat: Coal s

Information: A amphibian.

Ophiderpeton


Diet: Small inve

Habitat: Moist

Information: Anamphibian withand lived like aearthworm in thcover.

Arthroplura


Diet: Rotting vematter

Habitat: Coal s

Information: A millipede, 5 ft. long.

Crassigyrinus

Period: EarlyCarboniferous

Diet: Fish and oamphibians

Habitat: Coal s

Information: Amwith tiny limbs,head and a tape

Meaning: Early twisterTime: Late CarboniferousSize: 16 ft. 4 in.Diet: Fish and other amphibiansHabitat: Coal swamps

Information: One of the bigamphibians of the period, it cruisedthe shallow waters of the coalswamp like an alligator, looking forother animals to eat. Eogyrinuscouldspend some time on land, but it

needed to returnto the waterto breed.

EOGYRINUS

Meaning: Big nervesTime: Late Carboniferous

Size: 4 ft. 9 in. wingspan.Diet: UnknownInformation: Like a dragonfly, but

the size of a bird, Meganeurawastypical of the very large arthropods

that existed in the coal forests.Other anthropods includedcentipedes as big as pythons.

Meaning: From the countyof Westlothian in ScotlandTime: Early CarboniferousSize: 7 7/8 in.Diet: Small insects

Information: Westlothianais eitherthe earliest reptile known,or it is somethingbetween the amphibiansand the reptiles. It wascertainly the precursor of

the land-living animals to come.

WESTLOTHIANA

COAL FOREST PLANTSA R B O N I F E R O U STIMELINE

4290 MYA

The plant layers soaked up water and were pressed together, forming arown, spongy material, called peat.

More sediment layers formed on top of the peat, burying it deeper andeeper. The greater pressure and heat turned the peat into a brown coal,alled lignite.

3. More heat and pressure, at greater depths, turned the lignite into a soft,black coal, called bituminous coal.

4. This finally turned into a harder, shiny black coal, called anthracite.

FORMATION OF COAL

The period is named after the element carbon, whichwas abundant at this time.During the Carboniferous, mountain ranges were being

quickly eroded and the debris spread out into broad riverdeltas. The deltas were covered in thick forests thateventually formed the coal seams of the period.

Europe, the Carboniferousegarded as a single period.America, it is split in two.

nsylvanian 323290 MYAvalent to the late Carboniferous or

upper Carboniferous.ssissippian 354323 MYAvalent to the early Carboniferous orower Carboniferous.

erandlowerare terms used whenng about the rock sequences or thels formed. Earlyandlateare termsd when talking about the e ventshe time, such as the e volutioneptiles.

CARBONIFEROUS PERIOD

E PERIOD OR TWO?

THE WORLD IN THE CARBONIFEROUS PERIOD

By the Carboniferous period, life on the land had become fully

established. Coal forests are inhabited by gigantic insects and other

arthropods. The first reptiles begin to emerge during this time. The

period came to an end with an ice age that affected most of the southern

hemisphere.

Pennsylvanian

Mississippian

A N IPROF

MEGANEURA

Gzelian

Kasimovian

Moscovian

Bashkirian

Serpukhovian

Visean

Tournaisian

GONDWANA

PANGAEAPANTHALASSIC OCEAN PALAEO-TETHYS

SEA

Carboniferous


13/36

kinds of sea animals in earlier began to die outing the Permian period. In the region of Texas, theree thick reefs. Modern reefs are made of corals.mian reefse made of:

ponges

Algae

ivalves

rinoids (sea lilies)

rachiopods (animal with two shells but unrelatedo bivalves)

The Permian reefs of Texascontain the states oil reserves.

E R M I A NTIMELINE

0248 MYA

Zechstein

Rotliegendes

Changxingian

Longtanian

Capitanian

Wordian

Ufimian

Kungurian

Artinskian

Sakmarian

Asselian

MoschopsPeriod: Late Per

Diet: Plants

Habitat: Deserts

Information: A eating, mamma

Eryops

Period: Late Per

Diet: Fish and oamphibians

Habitat: Desert

Information: Obig amphibiansexisted at this ti

Lycaenops

Period: Late Per

Diet: Other rep

Habitat: Deserts

Information: A reptile that looka mammal.

Seymouria

Period: Early Pe

Diet: Insects anvertebrates

Habitat: Deserts

Information: Hathat were transibetween amphireptiles.

This period is named after the Perm region in Russia,where the rocks dating from this time are well exposed.In the Permian, nearly all the continents hadaccumulated into a single landmass. The mountains

during the Devonian and Carboniferous periods wereeroded into hills, and there was less erosion formingriver deltas. The coal forests dried up and were replacedby deserts.

Meaning: Middle lizardTime: Early PermianSize: 3 ft. 3 in.Diet: Small swimming animalsInformation: The age of reptileshad arrived, with swimming,flying, and land-living types.Fossils of Mesosaurus, afreshwater swimmer, havebeen found in South Africaand Brazil, showing thatthis area was all onecontinent at that time.

Meaning: Side-by-side lizardTime: Middle PermianSize: 8 ft. 2 in.Diet: PlantsInformation: Plant-eating vertebrates appeared at this time.Big-bodied types like Pareiasaurusfed on the ferns and conifersfound at desert oases.

At the beginning of the Permian period, the southern hemisphere was

still in the grip of the ice age that started at the end of the

Carboniferous period. Once the ice age ended, the Earth entered a

desert period, forming theNew Red Sandstone layer. The end of the Permian

period shows a large amount of volcanic activity, mostly in what will become

Siberia.

PERMIAN PERIOD

THE WORLD IN THE PERMIAN PERIOD

sert features seen inrmian rocks:une bedding

ed sandstones showing dryxidation environments

eds of coarse pebbles thatave been shaped by the wind

DESERT FEATURES

Meaning: Two sizes of toothTime: Early PermianSize: 9 ft. 8 in.Diet: Other reptilesInformation: An importantgroup of reptiles were themammal-like reptiles

that eventually gave rise to themammals. Dimetrodonwas an

early example. It had a sailon its back to help regulate

its temperature in thedesert heat.

DIMETRODON

REEFS

A N IPROF

PAREIASAURUS

MESOSAURUS

GONDWANA

PANTHALASSICOCEAN

PANGAEA PALAEO-TETHYSOCEAN

TETHYSOCEAN

Permian


14/36

e Triassic period is thest of the three periodsat make up theesozoic era.

Trias three. Refers to the threesequences of rock in Germany wherethe period was first identified.These are:Keuper desert sandstones and

marls.Muschelkalk musselchalk. Limestone marking a

marine phase.Bunter desert sandstones.

Classification still used, even thoughin most of Europe, the Muschelkalkis absent.

There are severalthe mass extinctio

1. The change to tcaused by the eSiberia.

2. Climate fluctuatthe joining of a

3. Chemical evidenfound in Austraof a meteorite inot strong evide

4. Change in the sthe ocean.

REASONS MASS EXT

TreesPermian giant club mosses

and cordaites, just like theCarboniferous coal forests.

Triassic primitive conifers likemonkey puzzle trees.

Medium-sized plantsPermian giant horsetails,

tree ferns.

Triassic cycad-like plants,tree ferns.

Small plantsPermian seed ferns and

horsetails.

Triassic conventional fernsand horsetails.

R I A S S I CTIMELINE

8206 MYA

MESOZOIC ERA

Because all the land was in a singlesupercontinent, the climates were extreme.

They could be divided into a number of belts.1. Year round dry climate.

2. Seasonal rainfall near the coasts.3. High latitude regions with cool rains.The interior of Pangaea was extremely hot duringthe Triassic, with little rain falling. Warm

temperatures extended down to thScientists think that this was one operiods of the planets history, withoccurring toward the end of the Tri

ew kind of plantssopteris(a kind of fern thatroduced by seed)becamey common. Its fossils are

nd throughout thethern continents.

All the continents had nowcome together to form onegreat supercontinent, calledPangaea.

All of the oceans were combinedinto one ocean, called Panthalassa.The New Red Sandstone conditionscontinued, with arid deserts in the

hinterland of the continent. Landlife was only possible around thecoast line.

After the Permian period ends, Earth began to change dramatically.

The boundary between the Permian and the Triassic periods

coincided with the greatest mass-extinction in Earths history, 95

percent of all species were wiped out. It is not known whether the volcanic

activity in what will become Siberia had anything to do with it, but following

the event, whole new groups of animals spread over the land and sea.

TRIASSIC PERIOD

THE WORLD IN THE TRIASSIC PERIOD

MEANING OF THE NAME

NEW PLANT LIFE

TRIASSIC CLIMATES

Rhaetian

Norian

Carnian

Ladinian

Anisian

Spathian

Nammalian

Griesbachian

Tr3

Tr2

Scythian, Tr1

GLOSSOPTERIS

Muschelkalk

Cretaceous 14465 MYA

Jurassic 206144 MYA

Triassic 248206 MYA

See page 45 for achart of the varying temperatures

throughout the Earths history.

210

PANTHALASSIC OCEAN

PANGAEA

GONDWANA

TETHYSOCEAN

PALAEO-TETHYSOCEAN

Warm temperate

Warm temperate Warm temperate

TropicalTropical Tropical

Para-tropical

Arid

Arid

Arid

Triassic

There were many differences between the plants of the Permian and Triassic periods.

W AR M

WET

DRY

Tropical

Wa

Paratropica

Ar

Coal

Baux

Later

KaoCroPal

Evapo

Calcre


15/36

Mixosaurus

Period: Late Tria

Diet: Fish

Habitat: Shallow

Information: Oearliestichthyofish-shaped swireptiles of the M

Nothosaurus

Period: Late Tria

Diet: Fish

Habitat: Shallow

Information: Swreptile that huntland.

Tanystropheus

Period: Late Tria

Diet: Fish

Habitat: Shallow

Information: A shore-living ani

Hyperodapedon

Period: Middle

Diet: Ferns

Habitat: Desert Information: Aone of the impoeaters before th

Erythrosuchus

Period: Early Tr

Diet: Other ani

Habitat: Deserts

Information: Ancrocodile relativthe fiercest hunthe dinosaurs.

The evolving plant life encouragedan evolving animal life as well.The plant-eating mammal-likereptiles declined as the seed-ferns

died out. A new line of plant-eatingmammal-like reptile evolved as theconventional ferns took over.Mammals and dinosaurs evolved,

and the conifers establishedthemselves at the end ofthe period.

CHANGING PLANTS, CHANGING ANIMALS

dence of reptile existencemes from the many footprintsund in Triassic sandstones.

mous localities include, Dinosaur Statek in Connecticut, Moab, Utah, andmfriesshire, Scotland.

There are several features that define a dinosaur and make it different from all other reptiles.

he begining of the Age oftiles, there were still plenty

big amphibians on Earth.

eptiles have hard-shelled eggs.

Amphibians lay soft eggs thatmust remain in water.

eptiles hatch fully formed fromhe egg. Amphibians go through larval tadpole stage, usuallyn the water.

eptiles have a toughwaterproof skin that can standp to dry conditions. Amphibiansave a soft skin covered in

mucus that must be kept moist.Meaning: Early hunterTime: Late TriassicSize: ft. 3 in.Diet: Small animalsInformation: The earliestdinosaur known. Having all thefeatures of an earlymeat-eating dinosaurabipedal stance with the head outto the front, balanced by a heavytail, small clawed hands, and longjaws with sharp teeth.

There was a significant change of life in the Triassic period. The varied sea creatures of the

Paleozoic era were gone, replaced by totally new types of water-living animals. The changed

plant life on land provided food for the new animal life. Land animals continued to develop and

pand; some developed the ability to fly or swim. It is during the Triassic period that the first

mmals and dinosaurs appear.

TRIASSIC LIFE

ARD-SHELLED EGG:THE KEY TO LAND-

LIVING

WHAT MAKES A DINOSAUR?

Meaning:Socket-toothed lizardTime: Late TriassicSize: 3 ft. 3 in.Diet: PlantsInformation: One ofthe first of the plant-eatingdinosaurs. Thecodontosaurushad alarger body than a me at-eater, to

hold a more complex digestivesystem, and a small head and along neck to reach its food.

THECODONTOSAURUS

Meaning: True two shapesof teethTime: Late TriassicSize: 3 ft. 3 in. wingspanDiet: FishInformation: One of the earliestpterosaursa group of flyingreptiles, related to dinosaurs, thatwere the lords of the skies in theMesozoic era. Eudimorphodonswings were formed by wingmembranes supported by along finger.

EUDIMORPHODON

A N IPROF

FOOTPRINTS

Mammal-like reptiles ate seed-ferns.

New reptiles, called rhynchosaurs evolved to eat the conventionalferns.

Dinosaurs evolved to eat the conifers.

EORAPTOR

Legs held vertically

beneath the body, notsticking out at the side

more like an elephantthan a crocodile.

A hole rather than a socket in thehip to hold the thigh bone.

Three or morevertebrae fusing thehips to the backbone.

Three or fewerfinger joints on

the fourth finger.

Skull with two holesbehind the eyes to hold

the jaw muscles.

Front legsshorter than

the hind.

See pages 1213 for moreinformation on FOSSILS.


16/36

The Newark Supergroup A series of mostly sandstones, laid down inrift valleys along the east coast of NorthAmerica, showing where Pangaea began to

break apart.

The Morrison Formation A sequence of river sandstones, shales,conglomerates, and evaporates laid down on an arid plain. It was crossedby rivers in the late Jurassic period of the American midwest.

U R A S S I CTIMELINE

6144 MYA

Rhomaleosauru

Period: Early Ju

Diet: Fish

Habitat: Shallow

Information: A with a big headintermediate foplesiosaurs (lonand pliosaurs (s

Ichthyosaurus

Period: Early JuDiet: Fish

Habitat: Open

Info: A mediumichthyosaur thamodern-day shslim, pointed snforeflippers twias its hind flipp

re were three mass-extinctionnts that took place at this time.

At the boundary between theTriassic and Jurassic. This killedthe last of the mammal-likeeptiles.

During the Pleinsbachiantage of the lower Jurassic. This

affected much of the dinosaurife.

At the very end of the Jurassicperiod. This had a greatereffect on sea animals thanand animals.

e of these were particularly large.

MASS EXTINCTIONS

The different mathe Jurassic are dspecies of ammoof squids and cutleft fossils of coil

Each species existefew million years, where they were fclosely dated. Eac

quite widespread tocean, so their fosin different parts o

Oolitic limestone Chemical sedimentaryrock made up of fine pellets ofcalcite. Good as a buildingmaterial.

Lias A series of interbeddedlimestone and deep water shale from

the earliest part of the period. It was laid downas deep water muds, and the limestone separated out as it solidified.

The beginning the Jurassic period was stilla time of deserts. However, as the ageprogressed, rift valleys appeared acrossPangaea, and the supercontinent began to

break up.

The most famous rift valley was the zig-zag rift thatbegan to split the Americas from Europe and Africa. Thiswould eventually form the Atlantic Ocean.

As North America began to move westward, the Rocky

Mountains began to build up before it.

Jurassic ismed after thea Mountains,ere AlexanderHumboldtstudied

estones in95. Hemed thisod Jurassicin

99.

The rocks that formed in the Jurassic period areextremely important in todays world as buildingmaterials and fuel.

The oilfields of the North Sea are Jurassic rocks. Much of London is built from late Jurassic Portland

limestone.

Although the dinosaurs appeared in the previous period, the Triassic,

it was during the Jurassic period that they took over and became the

most dominant creatures on Earth at that time. There were fewer

deserts then, because the supercontinent of Pangaea was splitting up and

spreading arms of the ocean and shallow seas across the landmass.

JURASSIC PERIOD

THE WORLD IN THE JURASSIC PERIOD

INDEX F

MEANING OF THE NAME

ECONOMIC IMPORTANCE

Hartford

Newark

Culpeper

Newark Supergroup(outcropping rift basins)

Fundy

Newark Supergroup

Malm

Dogger

Lias

Tithonian

Kimmeridgian

Oxfordian

Callovian

Bathonian

Bajocian

Aalenian

Toarcian

Pliensbachian

Sinemurian

Hettangian

A N IPROF

TYPICAL JURASSIC ROCKS

TWO JURASSIC ROCK SEQUENCES

See pages 1011 for more information on different TYPESOF ROCK.

PACIFIC OCEAN

GONDWANA

TETHYS OCEAN

LAURASIA

Jurassic


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Along the northern shore of the Tethys Seathe partof the ocean that separated the north and south partsof Panageashallow lagoons formed behind reefsbuilt by sponges and corals.

The bottom of the water was toxic, and it killed andpreserved many swimming and flying creatures.

These formed minutely-detailed fossils in veryfine limestone.

Archaeopteryx

Period: Late Jur

Diet: Insects

Habitat: Trees

Information: Thbut retaining mfeatures showinclosely related t

Opthalmosauru

Period: Late Jur

Diet: Fish

Habitat: Shallow

Information: A ichthyosaur, hadeveloped the wfish shape.

Metriorhynchus

Period: Late Jur

Diet: Fish

Habitat: Shallow

Information: Omarine crocodi

fish-like tail andlimbs.

Leedsihcthys

Period: Late Jur

Diet: Plankton a

Habitat: Open

Information: Obiggest fish thabut feeding on creatures, like twhale shark do

Meaning: Smooth-sided toothTime: Late JurassicSize: 39 ft. 4 in.Diet: Fish and plesiosaursInformation: Liopleurodonwasone of the big whale-likepliosaurs. Unlike their relativesthe plesiosaurs, these had shortnecks and massive heads. Theyprobably lived like modern sperm

whales, hunting big animals.

LIOPLEURODON

he animal life near the shore was different from that in the open water, which again was different from that of the deep seabed. Many species have been preserved as fossils in marine limestone and shale.

THE LIFE ON A CONTINENTAL SHELF

Meaning: Wing fingerTime: Late JurassicSize: 3 ft. 3 in.Diet: FishInformation: One of the first of thepterodactyloids, more advancedpterosaurs. These flying reptiles hadshort tails and longer wrist bonesthan earlier pterosaurs. Pterodactylus

can also be distinguished by theangle of the skull andthe neck.

Fossils of sea-living animals are more abundant than those of land-living ones, because the

majority of fossils are found in marine deposits. This does not mean that life was more abundant

in the water than on land during the Jurassic period, just that it was easier for marine animal

mains to become fossilized. The growing seas gave rise to broad continental shelves where sediment

lt up and trapped the fossils of the sea life of the time.

JURASSIC LIFE THE FOSSILS OF THE LAGOONS

CRYPTOCLIDUS

PTERODACTYLUS

A N IPROF

ea crocodiles hunt shoals of fish

Open water Deep water

Big fish hunthoals of tiny fish

Sea crocodiles hunt big fish

Plesiosaurs hunt fish

Pliosaurs hunt plesiosaursGiant fish hunt plankton

Pterosaurs hunt surface fish

Ichthyosaurs hunt belemnitesBottom-feeding sharks hunt shellfish

shore

Aerial creatures fall intothe lagoon.

Land-living animals are washedinto the lagoon by streams.

Sea-living creatures swim orcrawl in from outside andare poisoned.

coral reefssponges

limestone

eaning: Hidden collar boneme: Late Jurassicze: 26. ft 2 in.et: Fishormation:ypical plesiosaur, with the long neck, little head with pointed teeth,d paddle-like limbs. Cryptoclidusswam with a flying motion, like a modern sea lion.

See pages 1213 formore information on FOSSILS.


18/36

Compsognathus

Period: Late Jur

Diet: Lizards

Habitat: Island b

Information: A tsmallest dinosauso far.

Ceratosaurus

Period: Late Jur

Diet: Other dino

Habitat: Open pInformation: A smaller thanAlland armed withthe snout.

Apatosaurus

Period: Late Jur

Diet: Plants

Habitat: Open p

Information: A very similar to Dbut shorter and built.

Kentrosaurus

Period: Late Jur

Diet: Plants

Habitat: Open p

Information: A a stegosaur withplates and man

Brachiosaurus

Period: Late Jur

Diet: Tall treesHabitat: Open p

Info: A sauropoone of the tallesfound.

Megalosaurus

Period: Middle

Diet: Other dino

Habitat: Woode

Information: A the first dinosaudiscovered.

Time: Late Jurassic

Size: 98 ft. 4 in.Diet: PlantsInformation: Diplodocuswas a typical sauropod.It was balanced at the hipsso it could raise itself andreach into trees.Diplodocusused its tail asa defensive whip.

The most famous dinosaurskeletons were found inthe Morrison Formation inwestern North America.In the Jurassic period, this areawas a broad, dry plain betweenthe newly-formed Rocky Mountainsand a shallow sea that spreadacross the center of the continent.The plain was crossed by manyrivers, and most dinosaurs lived onthe forested river banks.

The most spectacular animals of Jurassic times were undoubtedly the dinosaurs. They ranged

from small fox-sized animals to creatures bigger than modern whales, and they lived

on all the continents of the world. Scientists can describe different groups of dinosaurs,

ch with their own lifestyles and habits.

JURASSIC DINOSAURS

DINOSAUR TYPES

Time: Late JurassicSize: 26 ft. 2 in.Diet: PlantsInformation: Theplates on the backof Stegosauruswereused either forprotection or a heatcontrol device.Stegosaurushas thesmallest brain relativeto the size of theanimal for anyknown dinosaur.

DIPLODOCUS

A N IPROF

Marginocephalians Dinosaurs witharmored heads. Mostly Cretaceous,they are divided into the boneheads

and the horned dinosaurs withthe shields around their necks.

heropods (Beast footed) The meat-eaters, walking on their hind legs,with small arms and the big teeth

held out to the front.

See page 29 for moreinformation on the MORRISON

FOUNDATION.

Sauropods (Lizard feet) The big plant-eatingdinosaurs with massive bodies, heavy legs,

and very long necks and tails.

Prosauropods (Before the sauropods) The earliestplant-eaters, with long necks and small heads.

Therizinosaurs (Scythe claws)ese seem to have been plant-eaters,

but were closely related to thetheropods. Their hips were more like

those of the ornithischians.

Thyrophorans Dinosaurs witharmor plates. Further dividedinto the plated stegosaurs

(mostly Jurassic) and the armored ankylosaurs(mostly Cretaceous).

Ornithischians (Bird hips)In this group of dinosaurs, the pubis bone in the hip is swept backalong the ischium bone, making room for a big stomach. They had abone in the front of the jaw that the saurischians lacked.

Ornithopods (Bird feet) The two-footed plant-eaters, although thebiggest ones spent most of their time on all fours.

urischians (Lizard hips)se dinosaurs were distinguished by their hips. The three main

nes of the hips radiated away from the hole where the leg wasached, as they do in modern lizards.

A DINOSAUR LANDSCAPE

STEGOSAURUS


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What was left of Pangaeacontinued to pull apart. Some ofthe continents were now in theshapes that we would recognizetoday.

Much of the southern landmasswas still present as a supercontinentthroughout the Cretaceous. Thiscomprised of what are now SouthAmerica, Africa, India, Australia, and

Antarctica. This supercontinent iscalled Gondwana. Gondwana splitup, with only Australia and Antarcticastill joined.

R E T A C E O U STIMELINE

465 MYA

Deinosuchus

Time: Late Creta

Diet: Dinosaurs

Habitat: Swamp

Information: Thcrocodile know

Archelon

Time: Late Creta

Diet: Jellyfish

Habitat: Open

Information: Pebiggest turtle thexisted.

Pleurosaurus

Time: Early Cre

Diet: Fish

Habitat: Open

Information: Littswimming reptito the modern t

Pteranodon

Time: Late Creta

Diet: Fish

Habitat: Open

Information: Bigfishing pterosau

Tapejara

Time: Late Creta

Diet: Fruit

Habitat: Forests

Information: Ptethe most colorfu

Pterodaustro

Time: Late Creta

Diet: Fine crusta

Habitat: Inland

Information: A with jaws like sflamingo.

re were more dinosaurs aroundng the Cretaceous than theree previously. This is becausehe different isolated continentsdifferent types of dinosaursving on them.

IVERSE DINOSAURS

Meaning: Swollen lizardTime: Late CretaceousSize: 32 ft. 8 in.

Diet: Ammonites and othersea animalsInformation: A typical bigmosasaur. Closely related to modern

monitor lizards but with paddle-shaped limbs and a flattened tail.Tylosaurus and its relatives would

have pursued the same prey andhad the same lifestyle as theichthyosaurs of the precedingJurassic period.

The shallow seas that spread everywhere atthe end of the period were full of differenttypes of sea animals. The ichthyosaurs were gone,

but were replaced by a different group of sea reptiles,the mosasaurs. The pterosaurs continued to rule theskies but birds were present as well.

Meaning: Long lizard

Time: Late CretaceousSize: 49 ft. 2 in.Diet: FishInformation: Elasmosaurushad the longestneck of all the plesiosaurs, comprising 71vertebrae and taking up more than half thelength of the whole animal. It swallowedstones to aid digestion and to adjust itsbalance while swimming.

tais the Latin word for chalk. Vastosits of this very fine limestonee laid down on the shallow sea

ves at that timeparticularly in

southern England, northern France, andKansas.

The dinosaurs continued to evolve as the Mesozoic moved

forward. During the Cretaceous period, the continents moved away

from each other and the dinosaurs diversified. The period was

brought to a shuddering end by a sudden event that destroyed the dinosaurs.

The age of reptiles was over.

CRETACEOUS PERIOD

MEANING OF THE NAME TYLOSAURUS

ANIMALS OF AIR AND SEA

Meaning: Lizard of KronosTime: Early CretaceousSize: 32 ft. 8 in.Diet: Ammonites and other sea animalsInformation: Kronosauruswas the biggestof the pliosaurs certainly the one with thebiggest head, 2.7 metres (8 ft 9 in) long. Acreatures skull was found in Australia but noneof the rest of the body has been unearthed yet.

Meaning: Named after Camille Arambourg,who first described it in the 1950sTime: Late CretaceousSize: 39 ft. 4 in. wingspanDiet: Probably fishInformation: Scientists continue finding biggerand bigger pterosaur bones and announcingthat this must have been the biggest animalthat could possibly fly. The current recordholder is Arambourgiania.

THE WORLD IN THE CRETACEOUS PERIOD

ELASMOSAURUS

A N IPROF

Gulf

K1

Senonian

Gallic

Neocomian

KRONOSAURUS

ARAMBOURGIANIA

pterosaurs

mosasaurspliosaurs

elasmosaurs

orth America Europe

Asia

Africaoutherica

See pages 1011TYPES OFROCK.

TETHYS OCEAN

SOUTHATLANTIC

PACIFIC OCEAN

ARCTIC OCEAN

NORTHATLANTIC

PROTO-CARIBBEANSEA

Cretaceous


20/36

amosaurus

me: Late Cretaceous

et: Trees

bitat: Woodland

ormation: The lasturopod of North America.

gentinasaurus

me: Late Cretaceous

et: Treesbitat: Woodland

ormation: A titanosaur.e heaviest dinosaur yetcovered.

nithomimus

me: Late Cretaceous

et: Omnivorous

bitat: Open country

ormation: Ostrich-liked very quick.

otoceratops

me: Late Cretaceous

et: Desert vegetation

bitat: Desert andubland

ormation: An earlyrned-dinosaur.

uroposeidon

me: Early Cretaceous

et: Treesbitat: Woodland

ormation: One of the lastd biggest of theachiosaurs.

ryonyx

prehistoric world

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