byLeighClarkp.3,©LouiePsihoyos/ScienceFaction/GettyImages;p.4-5,©Gerald&BuffCorsi/VisualsUnlimited;p.6,©JamesL.Amos/CORBIS;p.7,©FrancoisGohier/PhotoResearchers,Inc.;p.8-9,JoeLeMonnier:p.10,©ScottW.Smith/AnimalsAnimals;p.11,©GregMartin/SuperStock;p.12,©FrancoisGohier/PhotoResearchers,Inc.;p.14,©DaveG.Houser/Post-Houserstock/Corbis.Copyright©byHarcourt,Inc.Allrightsreserved.Nopartofthispublicationmaybereproducedortransmittedinanyformorbyanymeans,electronicormechanical,includingphotocopy,recording,oranyinformationstorageandretrievalsystem,withoutpermissioninwritingfromthepublisher.RequestsforpermissiontomakecopiesofanypartoftheworkshouldbeaddressedtoSchoolPermissionsandCopyrights,Harcourt,Inc.,6277SeaHarborDrive,Orlando,Florida32887-6777.Fax:407-345-2418.HARCOURTandtheHarcourtLogoaretrademarksofHarcourt,Inc.,registeredintheUnitedStatesofAmericaand/orotherjurisdictions.PrintedintheUnitedStatesofAmericaISBN10:0-15-350333-8ISBN13:978-0-15-350333-1OrderingOptionsISBN10:0-15-350334-3(Grade4Below-LevelCollection)ISBN13:978-0-15-350334-4(Grade4Below-LevelCollection)ISBN10:0-15-357528-X(packageof5)ISBN13:978-0-15-357528-0(packageof5)Ifyouhavereceivedthesematerialsasexaminationcopiesfreeofcharge,HarcourtSchoolPublishersretainstitletothematerialsandtheymaynotberesold.Resaleofexaminationcopiesisstrictlyprohibitedandisillegal.Possessionofthispublicationinprintformatdoesnotentitleuserstoconvertthispublication,oranyportionofit,intoelectronicformat.1234567891017912111009080706byLeighClarkSomewhereonamountaininUtah,aworkerchipsawayatarock.Graduallythepiecesofrockfallaway,andthebonesofadinosaurappear.ThisworkerandmanyothersatDinosaurNationalMonumentinUtahspendtheirdaysearchingforfossils.Afossilistheremainsofananimalthatlivedlongago.Itcouldbeaboneorafootprintthathashardenedinstone.3Millionsofyearsago,dinosaurslivedinmuchofthelandthatisnowtheUnitedStates.Overtheyears,asthedinosaursdiedout,manyoftheirbodiessankintotheEarthandformedfossils.Fossilsarenottherealbonesofadinosaur.A...
