meaning thick headed greek thick head genus type species known species lived late cretaceous period stage north_america remains excavated montana south wyoming creature primarily known single skull extremely thick skull roofs complete fossils found recent years non cretaceous extinction event dinosaur western north_america like extremely thick skull roof possessed long small largest known thick skull related genera gave rise hypothesis species combat hypothesis disputed recent years description anatomy poorly known skull remains described famous having large bony dome atop skull thick safely tiny brain dome rear aspect edged bony short bony spikes projected upwards snout spikes probably blunt sharp skull short possessed large rounded eye faced forward suggesting animal good vision capable vision small muzzle ended pointed teeth tiny leaf shaped crowns head supported neck probably largest bone headed estimated metres long weighed kilograms based probably fairly short thick neck short fore limbs body long hind legs heavy tail likely held rigid history discovery remains found early 1850s determined ferdinand early fossil collector north american west collected bone fragment vicinity head missouri river known lance formation southeastern montana specimen described joseph belonging dermal armor like animal known actual nature found century later identified bone skull including set bony corresponding found specimens according international code nomenclature normally preferred successfully petitioned instead years based materials poor geographic information end story robert sullivan suggested like corresponding bone issue uncertain importance actually represents juvenile recently proposed type currently valid species named charles coined partial skull lance formation county wyoming assigned new species time thought known teeth similar teeth accordingly known assigned family corrected charles brown newer complete material established genus named species type species genus based nearly complete skull hell creek formation carter county montana based dome associated elements lance formation county south referred older species new genus newer species considered synonymous classification gives clade bird lived late cretaceous period north_america asia despite stance likely closely related famous member best preserved member clade includes tribe closely related juvenile forms modified evans growth specimens dome horns developed animal juvenile female consideration supported annual meeting society jack montana state university presented evidence analysis skull single existing specimen dinosaur juvenile form addition presented data indicates juvenile forms published findings showing spike skull dome bones species exhibit extreme known juvenile specimens known adult specimens observations addition fact forms lived time place lead conclude simply juvenile lost spikes grew aged discovery baby assigned described different bone beds hell creek formation presented evidence hypothesis fossils described david evans mark identical supposed genera placement studies different mature suggested present skull developed early dinosaur life iconic head developed later study nick colleagues supported hypothesis flat juveniles suggesting flat forms like represent juveniles dome adults fighting behavior scientists suspected relatives sheep male individuals ram believed head neck body horizontally straight order transmit stress believed way foremost skull roof probably adequately sustained impact associated definitive evidence damage recent findings furthermore anterior dorsal neck carried curve straight orientation unfit direct head lastly rounded shape skull contacted surface area head resulting blows scan head striking supported equipped head alternatively genera engaged flank combat scenario individual stood roughly parallel faced rival directly intimidation displays cow rival intimidation failed bend head downward striking rival flank hypothesis supported relatively broad width trait protected vital organs harm flank theory proposed expanded carpenter study showed specimen likely behavior proposed similar damage specimens previously explained artifacts bone instead behavior studied found examined consistent infection bone resulting penetrating trauma trauma tissue skull leading infection bone tissue high rate support hypothesis employed specific combat specimen observed frontal bone specimen observed frequency trauma comparable different genera family despite fact genera vary respect size architecture fact existed varying periods findings stark contrast results analysis relatively flat headed absence support hypothesis individuals represent females juveniles specific combat behavior expected examination reveals composed unique form bone contains play critical role wound healing capable rapidly bone concluded taken frequency distribution bone structure strong support hypothesis unique structures behavior diet scientists know ate having small teeth tough plants effectively period assumed lived mixed diet leaves seeds fruit insects sharp teeth effective plants nearly fossils recovered lance formation hell creek formation western united_states possibly existed alongside additional species genera represent juveniles regarded valid species shared time place include possible species like popular culture appeared appeared books television media featured installments park franchise related media particularly michael lost world novel film adaptation lost world park portrayed large smaller close relative starring role main playable simulation game video game


family early likely basal primitive members group fossils relatively rare group small numbers lived continents australia antarctica approximately million years late early cretaceous fox sized metres feet length including long tail known mainly characteristic teeth including enlarged like cheek teeth adapted analogous cretaceous diet possibly description known complete skeleton skeletal remains known fully described known jaw fragments teeth consequently defining features described teeth jaw bones measured meter length remains indicate larger individual skull teeth large eyes underneath eyes bone projected sideways feature present jaws anterior edge bone tip upper jaw probably supported teeth posterior section large gap called separated teeth main upper jaw bone arched lower jaw tipped bone unique bone supported similar found teeth lower jaw found bone named strongly teeth early teeth small conical larger tooth resembled mammals called lower larger upper took position accommodated arched upper jaw mouth closed anterior posterior edges bore anterior edge early cretaceous upper late lower like characteristic cheek teeth derived unique early small ridges denticles lined edges cheek teeth order crop vegetation denticles extend way tooth crown tip denticles extend root basal forms like cheek teeth generally similar widely spaced having low crown strongly developed ridge separating crown root derived forms like teeth shaped higher crowns difference width crowns roots derived cheek teeth overlapping crowns formed continuous surface food tooth rows slightly mouth leaving space outside teeth bounded muscular cheek necessary cretaceous period mammals evolve somewhat analogous dental batteries opposed thousands teeth constantly replaced tooth replacement occurred far slowly specimens found single replacement tooth waiting lacked small openings inside jaw bones thought aided tooth development boasted unique joint allowing lower jaws rotate mouth closed grinding cheek teeth slow replacement rate grinding produced extreme tooth wear commonly denticles older teeth increased height crowns gave tooth long life skeleton anatomy described generally considered derived early impossible know features shared species long dinosaur length developed crest ridge attachment chest shoulder muscles prominent process muscles extend attached indicate powerful hand large tipped sharply curved rotate robert called twist thumb second digit longest slightly longer bore claws fourth fifth small simple comparison longer generally considered adaptation speed lower leg fused ankle forming modern birds similarly birds lower ankle bones fused form second fourth contacting ground tail unlike maintain rigid posture probably flexible skeleton known fully described smaller fourth fifth bear fewer bone feathers china appears preserve interpreted variant feathers found include crest tail presence suggest classification south african robert created dinosaur jaw bones missing teeth named classified named recognized closely related alfred named family including defined clade paul stem clade consisting species closely related includes genera south_africa richard reassigned authors consider genera distinct family considered sister taxa basal member usually considered type specimen missing teeth making indistinguishable genus family recently genus considered studies named upper jaw recent discoveries shown belongs instead making junior synonym genus considered asia shown remains remains classified south american time animal known basal membership established comparison uncertain phylogenetic position early studies suggested primitive supposed similarities morphology robert proposed relationship early like orders dominant hypothesis decades placed basal suggested instead share common ancestor hypothesis found support early 21st century studies clade containing named seen basal analysis suggested basal known result echoes earliest work family butler found basal known significant radiation shows follows analysis distribution originally known early southern africa remains known continents early history largely intact allowing family achieve near worldwide distribution oldest known remains jaw fragment isolated teeth formation argentina dates late remains derived morphology similar including anterior posterior edges high crowned teeth lacking diverse fauna comes early southern africa fossils dubious found early known united_states mexico respectively addition beginning 1970s great deal fossil material discovered late morrison formation near colorado united_states described print material placed genus teeth lacking described late early cretaceous formations spain portugal remains showing represent late surviving stage early cretaceous southern england early china longer considered late surviving asian form known fossils found formations represent arid semi arid environments including upper formation south_africa beds southern england suggested underwent seasonal times year lack replacement teeth proposed entire set teeth replaced dormant period continual sporadic replacement teeth function tooth row single surface based misunderstanding jaw mechanics thought actually replace teeth continually slowly reptiles scanning juvenile mature shows replacement teeth currently evidence supports hypothesis rejected based skull cheek teeth clearly adapted grinding tough plant material diet pointed teeth sharp curved claws suggest degree predatory behavior suggested long powerful useful tearing insect nests similarly modern functioned digging tools roots length compared suggests partially prominent process found clearly designed weight support features including long foot fusion indicate adapted run quickly unlikely moved limbs feeding short found known strongly resemble found modern deer pigs animals longer asian elephants sexually trait found males type specimen lacks originally described female remains possible short face indicate specimen represents juvenile animal second larger specimen clearly possesses possible found adults secondary sexual characteristic males combat display members species species absence juvenile characteristic separating known juvenile proposed functions include defense use occasionally diet


meaning comparison later dinosaur similar head crest genus duck billed dinosaur late cretaceous north_america known remains individuals belonging species including skeletons remains obscure fossils found late age upper cretaceous dinosaur park formation alberta roughly contemporaneous medicine formation montana dating million years ago recognizable feature small solid crest formed nasal bones sticking eyes type species described american brown american museum natural history second species described jack museum species differentiated mainly crest size skull proportions description large headed complete described specimen skull metres long skeleton metres long small stout triangular crest eyes sides crest concave forming depressions upper arm relatively short originally described brown known skull jaw half skull badly time examination level crushed upwards different bones skull easily defined exception nasal bones brown found skull described genus similar overall smaller skull unique feature shortened frontal found lack shorter frontal genera share elongated history discovery known brown recovered skull american museum natural history red deer river alberta near described specimen new genus brown choice comes comparison genus described similar longer spike like head crest skull damaged muzzle inadvertently reconstructed long better remains soon found showed true shape nearly complete skeleton skull described william parks individuals known species including seven rest skeleton second species based specimen museum described notable jack specimen remains individuals found county montana case fossils found remains indicates animals lived time interpreted reflecting group animals near water source drought differentiated species details crest interpreted having taller face crest migrating backward eyes growth recent studies regarded differences insufficient support species classification associated contentious authors found animals closely related instead finding closer history classification lawrence revised classifications family replacing subfamily included split found genera remaining type genus previous genera reclassified assigned group contained males median horn like skull numerous teeth found charles genera probability sunk greatly changed classifications family kept separate supposedly identified assigned found assigned location find noted william parks found complete skeleton clearly showing realized meant unlikely possessed led abandonment young found subfamily abandoned placed new genus included excluded years previous friedrich von separated naming family including genera probably unrelated author support separation john found possessed crest feature united distinguishing hollow supported division suspect modern analyses find found clearly divided groups including intermediate followed sinking like recognized groups subfamily like group called lineage second group uniting decade later scientifically named groups second phylogeny analysis encompass conducted found synonymous separated subfamily groups group included contained detailed relationships published study led recovered similar position suggested brown recovered analysis studied wagner genus considered wagner synonymous respectively reassigned year found distinct analysis analysis unique time recovered analysis recovered group recovered different phylogeny time recovered separate fact closely related found group grouped clade problematic grouping trying place skull features similar closer group classified close clade closer features numerous uniting large eating plants sophisticated skull permitted grinding motion analogous teeth continually replaced packed dental batteries contained hundreds teeth relative handful use time plant material broad held jaws cheek like structure feeding ground meters like moved comparisons rings modern birds reptiles suggest active day short intervals social behavior noted evidence genus lived groups year additionally potential methods display social setting bony facial crest obvious candidate nasal present taken form soft tissue housed deep excavations flanking crest holes nostrils visual signals dinosaur park formation home interpreted low relief setting rivers influenced marine conditions time western interior westward climate warmer present day alberta frost drier seasons conifers apparently dominant canopy plants tree flowering plants studied formation known upper marine influence lower section common section deposited million years ago dinosaur park formation home known like fellow armored roughly contemporaneous medicine formation home known fossils dinosaur nests eggs young produced armored present formation distant western interior higher drier dinosaur park formation age remains formation approximately million years ago


dinosaur egg found southwestern europe eggs large centimetres inches diameter spherical outer surface smooth covered subdued pattern ridges interspersed pits grooves multiple fossil egg known nest structure unclear parent probably kind non possibly eggs named classified distinct considered belong single possibly single classified usually placed description eggs spherical fairly large measuring diameter outer surface smooth covered subdued pattern ridges interspersed pits grooves ornamentation partially column shaped shell units range thick egg known containing eggs unfortunately alterations changes process difficult determine original structure nest cousin eggs laid surface ground possibly buried beneath mound plant matter noted shell high rate water concluded nests covered organic material similar modern eggs high described type slightly thicker slender partially fused units outer surface ornamentation inner surface covered filled organic exhibits system pores long narrow straight classified distinguished thinner measuring thick broader units relative prominence ornamentation like typically system specimens pores meaning variable diameter length authors consider synonymous cousin argued differences variation described fragments possibly belong additional distinct specimens referred classification considered considered belong belongs basic type group including eggs eggs excluding eggs analysis recovered sister taxon clade eggs considered likely belongs non dinosaur embryos unknown eggs identity parent uncertain long considered eggs like numerous characteristics distinguish eggs bear superficial similarities size shape units unlike fan shaped ones seen subdued ornamentation contrasts strongly heavily sculpted eggs different system eggs hand closer similarity ornamentation system eggs typically smaller crystal structure units distinct analysis supported late cretaceous southwestern europe restricted analyzed largest known found laid eggs big hand relatively small unique orientation easily allowed lay eggs large egg interpreting eggs raise question similar eggs found areas greater abundance distribution native southwestern europe including southern france northern fossils date late early usually found basin limestone site france grand basin found northern southern france village crete basin late cretaceous ecosystems europe island archipelago complex mixing taxa originating africa asia north_america southwestern europe occurs numerous types fossil eggs particularly common eggs egg present dinosaur body fossils common including basal include bony fish turtles mammals history basin excavated fossils french 1950s pair french working museum extensively studied basin fossil divided eggs found different types describe detail 1970s 1980s work french german devised early classification schemes egg fossils doctoral thesis recognize eggs named distinct type classification scheme called group french described modern system assign classified russian following discoveries french cousin took step fossils discovered outside france reported albert phd thesis barcelona proposed moved years later angel published comprehensive formally named new contain contrary cousin conclusions separated demonstrated eggs eggs


meaning chinese wing chinese pinyin literally china dragon bird dinosaur described dinosaur taxon outside birds immediate relatives found evidence feathers covered coat simple like feathers structures indicate preserved feathers makes non determined includes reddish light banded tail contention arisen alternative interpretation impression remains widely accepted small unusually long tail short arms longest known specimen reaches metres feet length estimated weight kilograms pounds close relative similar older genus genera belonging family species named meaning reference status non dinosaur species discovered specimens described specimen previously assigned genus represents second unnamed species distinct related genus lived northeastern china early cretaceous period discovered formation province member preserved fossils species illustrate aspects biology diet reproduction description small noted short arms large finger long tail taxon includes smallest known adult non specimens specimen measuring length including tail individual relatively young longest known specimen reaches length estimated weight similar differing european relatives proportions skull longer thigh bones unlike skull thigh bones approximately equivalent length arms radius length legs thigh bone compared additionally features unique tail high number tail longest relative body length hands long compared arms length rest arm radius half length foot second length large digit fingers large longer thicker bones teeth differed slightly based position near tips upper jaws slender lacked compressed teeth lower jaws similarly differentiated area abdomen suggested possible traces organs interpreted liver john colleagues described like respiratory system later study agreeing area represented originally inside body found defined structure noted organs distorted processes flattened skeleton essentially dimensional form dark pigment present eye region specimen feathers described specimens preserve structures arising skin interpret primitive type feathers short like preserved half skull arms neck tail additional patches feathers identified sides body proposed density feathers patches body indicated animals fully life ventral feathers having removed preserved gap bones authors noted corresponds closely expected skin muscle tissue present life feathers closest bone skull end tail little muscle present gap increases expected indicating external skin correspond structures exhibit random interpreted evidence soft life microscopic examination shows individual appear dark edges light internally suggesting hollow like modern feathers compared modern mammals coarse individual strand larger thicker corresponding hairs similarly sized mammals length varies body type specimen shortest eyes length going body rapidly increase length reaching lengths shoulder blades length remains uniform reach maximum length midway tail underside tail shorter overall decrease length rapidly dorsal surface 25th tail underside reach length longest feathers present measured feathers dense single structure examination studies suggested presence distinct types thick thin interspersed thick tend appear thin thin tend lie parallel angles nearby thick properties suggest individual feathers consisted central thinner branching similar primitive structure modern bird feathers overall closely resemble like feathers modern birds thick central long thin structures seen fossils formation including feather like structures closely related previous bird dinosaur closely related including indicates feathers characteristic obviously bird like ones making possible equally distant animals feathers dinosaur life described scientists based physical evidence fossils lighter darker bands preserved tail colleagues initially interpreted banding pattern artifact splitting main slab counter slab original specimen preserved suggested presentation society specimens actually preserve remnants pattern animal exhibited life argued dark banded areas tail evenly spaced caused random separation fossil represent present feathers additionally artifact preservation presence dark feathers body reflect colour pattern life indicating dark lighter underside bands stripes tail camouflage conclusions supported paper published online journal nature january colleagues examined feathers early birds found evidence preserved cells feathers modern birds colour specimens studied previously specimen examining structure distribution colleagues able confirm presence light dark bands colour tail feathers furthermore team able compare types modern birds determine general range colour presence spherical store red pigment concluded darker feathers chestnut reddish brown colour classification despite feathers consider birds genus related clade usually defined plus modern birds scientists described character based definition class animal feathers considered bird argued represent true feathers considered true bird classified genus belonging new biological order family proposals accepted generally classified family group small bodied long tailed known late early cretaceous asia europe south_america showing placement named species possible second species represented specimen aka described larger specimen presentation abstract society nick showed specimen differs aspects including relatively large size longer shorter tail suggested proper primitive kind basal concurred specimen probably new taxon tentatively classified suggested belong new genus colleagues wrote probably new genus noting differences tail length proportions distinguishing features identified features set apart birds found small primitive bird relatively high skull blunt slightly high elliptical enlarged robust narrow elongated extremely developed acute extremely elongated body length extremely short short thick elongated extremely inflated end broad hind limb long robust slightly longer separated relatively robust ends feathers short small uniform skull dorsal regions addition dorsal ventral caudal region history discovery fossil specimen dinosaur later named uncovered august farmer time fossil hunter province acquire fossils sell individuals museums recognized unique quality specimen separated sold separate museums china national geological museum beijing institute geology director beijing museum recognized importance find visiting canadian artist michael aware fossil chance explored beijing museum collections leading fossil tour area week october recognized significance fossil immediately new_york_times quoted saw slab stone mixed volcanic ash creature embedded bowled originally described authors named meaning chinese wing chinese authorities initially barred photographs specimen publication brought photograph meeting society american museum natural history new_york causing crowds gather discuss new discovery news reportedly left john 1970s pioneered theory birds evolved state shock later joined international team researchers gathered beijing examine fossils team members included feather expert brush fossil bird expert larry martin peter expert early bird specimens assigned counter slab opposite face specimen assigned genus species colleagues assignment additional larger specimen later found error fossils found beds formation regions china fossil beds dated million years ago late early stages early cretaceous identity controversy identity preserved specimen began immediately team scientists spent days beijing examining specimen microscope results studies reported press conference philadelphia academy natural sciences thursday april inconclusive team agreed structures preserved modern feathers suggested research required discover exact nature examined specimen wrote magazine structures considered time synonym structures running dinosaur engaging thinking structures feathers subsequent publications saw team members identity structures argument followed publications researchers interpreted impressions fossils remains primitive feathers structures clearly external body researchers proposed formed animal underside tail similar modern aquatic absence feathers proposal basal known genus feathers raise questions current theory feather origins calls question idea feathers evolved flight appearance relatively basal dinosaur later evolved modern birds researchers disagreed identification structures structural notably team scientists reported presence cells structures argued presence proved structures feathers contain pigment gregory paul hypothesis proponents consider body outline outside preparation brushed outline body diet specimen preserved remains gut region indicating small fast moving animals diet numerous type found rocks described possible specimen found jaws gut region identified jaws belonging showing mammals animal diet known spur ankle like modern indicate fed possibly mammals reproduction specimen preserved stomach contents small eggs abdomen eggs preserved boot lie underneath slab unlikely eaten animal wrong body cavity egg shells remained intact likely eggs produced animal egg measured long wide presence developed eggs suggests dual laid eggs pairs like formation dinosaur member organisms found formation formation formation composed largely volcanic rocks volcanic layers beds rocks representing deposition lake freshwater lake strata formation preserved wide variety plants invertebrates forests extensive early flowering plants insects diverse abundant mammals birds known formation setting subject periodic mortality events including volcanic gases lakes climate interpreted temperate distinct wet dry seasons yearly temperature time period averaged degrees degrees indicating temperate climate unusually cold winters generally warm era possibly northern china high latitude time


cry genus large known single species known early period antarctica metres long kilograms weight making largest time individuals species grown larger known specimen probably represents sub adult known skull material skull caused classification vary greatly possesses primitive characteristics classified outside skull advanced features leading genus considered original description consensus primitive member close relative group possessed distinctive crest head spanned head similar spanish based evidence related species studies bone texture thought bizarre crest species recognition brain primitive excavated antarctica early aged formation upper formation william hammer dinosaur discovered antarctica non dinosaur continent officially named sediments fossils found dated million years ago representing early period description fully described specimen specimen consists incomplete skull lacking half teeth sixth posterior ribs anterior dorsal mid posterior dorsal dorsal ribs fifth partial complete caudal partial radius partial incomplete end end new material unearthed antarctica description material published non abstract form large built largest time genus described roger colleagues predator antarctica slender proportions estimated length william hammer william study smith revised length weight estimated kilograms based length weight estimates currently largest known early smith noted individual probably represents sub adult adults larger skull consists high narrow skull discovered articulated rest skeleton skull estimated centimetres long peculiar nasal crest runs eyes rises perpendicular skull fans thin highly giving spanish like appearance crest extension skull bones near tear fused horns rise eye like usually run skull instead unpublished study conducted chin suggested previous studies lacked focus details study found fossil nearly complete cavity complete approximate shape size living brain features clarified skull giving basal position classification classification difficult mix primitive advanced characteristics traits early skull resembles later species clade like china led paul place taxon originally hammer colleagues suspected early traits advanced ultimately concluded earliest known member group subsequent study hammer smith recovered later study authors found closely related sterling characters found instead sister group clade composed matthew found related unrelated following family tree illustrates synthesis relationships early groups compiled discovery naming originally collected summer mount region mountains discovery hammer professor college team fossils found formation upper formation dated stage early second dinosaur discovered antarctica discovered named earlier hammer ohio_state university david excavated separate near sharing logistical expenses team came remains rock formation altitude high south pole discovery soon notified hammer weeks hammer excavated fossil bearing rock team recovered fossil bones including specimens formally named described hammer journal science season field team returned collected material original site second locality discovered metres higher section derived greek words meaning cold frozen reference discovery antarctica meaning crest meaning cold crest hammer named species david initial discovery fossils ornamentation display features possessed sense social animals members species available observe interpret messages sexual status kevin challenged conventional purpose bizarre structures post armor attracting mates intimidating fighting rivals group intimidating potential predators species noted based phylogenetic functional evidence bizarre structures explained phenomenon species recognition supported fossil evidence thomas found bizarre crest primarily species recognition based evidence related species studies bone texture according thomas rich colleagues crest ineffective weapon possibly functioned display feature certain types social behavior mating diet type specimen discovered long ribs supposed dinosaur found mouth led hammer conclude feeding died hammer noted ribs found extending way neck region individual death ribs smith concluded remains belonged specimen hammer hammer concluded post tooth belonging early relative found remains stomach contents died bones evidence broken teeth different found nearby possible found ankle bone bone preserved small located ankle unique morphological feature known specimens recovered formation major dinosaur bearing rock formations found continent antarctica discovered deposited stage early approximately million years ago geological formation victoria group mountains approximately metres sea level high altitude site supports idea early antarctica forests populated diverse range species coast formation deposited active volcano rift system formed breakup early antarctica closer equator world considerably warmer today climate cool temperate models air flow indicate coastal areas probably dropped freezing extreme conditions existed inland found kilometres south pole time lived farther north formation produced remains large basal crow sized type size rat unknown case james martin informally recovered partial remains large dinosaur formally described remains plant genera recovered early camp hill formation age fossils proving dense plant matter grown antarctica surface drifted southward


meaning spine genus dinosaur lived north_africa lower lower stages cretaceous period million years ago genus known egyptian remains discovered described german original remains destroyed world war additional material come light recent years unclear species represented fossils reported scientific literature best known species egypt potential second species recovered morocco largest known possibly larger estimates published suggested metres length tonnes short tons weight new estimate published based complete specimen supported earlier research finding reach lengths greater skull long narrow similar modern known eaten fish scientists believe hunted terrestrial aquatic prey evidence suggests lived land water modern distinctive spines long extensions grew meters long likely skin connecting forming sail like structure authors suggested spines covered fat formed multiple functions forward structure including display description discovery contender longest largest dinosaur friedrich von listed massive surveys meters length upwards long tons short tons weight gregory paul listed longest meters gave lower mass estimate tonnes long tons short tons assumed body proportions relation skull lengths calculated meters length tonnes long tons short tons weight estimates criticized skull length estimate uncertain assuming body mass increases cube body length scaling meters long tonnes short tons mass range estimated lengths produce estimated body mass tonnes short tons henderson paper scaling based skull length challenged previous estimates size finding length great weight small based estimated skull lengths meters estimates include body length meters body mass tonnes long tons short tons lower estimates imply animal shorter lighter henderson study criticized choice comparison set initial different build assumption skull little meters length improvement precision size estimates requires discovery complete remains available especially limb bones hitherto unknown spines tall spines growing formed basis usually called animal sail lengths spines reached times bodies extended spines slightly longer base higher unlike thin rods seen contrasting thicker spines sails unusual lived million years earlier general region south american developed similar structural adaptations sail analog sail lived appeared produced evolution structure like sail like noted think existence large fat german spines gave internal support jack bailey support buffalo hypothesis bailey argued long spines spines relatively shorter thicker spines known sails instead spines similar spines extinct backed mammals skull skull narrow snout filled straight conical teeth lacked seven teeth upper jaw second teeth noticeably larger rest teeth creating space large teeth anterior large teeth lower jaw faced space tip snout holding large anterior teeth expanded small crest present eyes dimensions specimens known viii assuming skull shape similar skull estimated skull meters long skull length estimate questioned skull shapes vary species study performed scientists andrew emily showed like relatively poor resistance compared members group modern showing preyed regularly fish land animals considered predators classification gives family includes include southern england central africa include brazil probably synonymous brazil share straight teeth widely spaced opposed curved teeth numerous following shows analysis simplified discovery naming naming species species named meaning egyptian spine meaning spine described remains found described early 20th century richard discovered partial skeleton dinosaur formation western egypt german published article assigning specimen new genus species additional remains including bones designated considered different belong species borne advantage expeditions material appears originally described russell new species based length neck specifically russell claimed ratio length body height posterior later authors split topic authors note length vary individual individual specimen destroyed compared directly specimen unknown specimens represent retained species valid comment researchers regard junior synonym specimens main partial specimens described viii described formation material consisted following items incomplete right left lower jaw measuring centimeters long straight piece left described drawn teeth dorsal trunk caudal ribs spines heights given longest associated dorsal meters length claimed specimen early approximately million years ago specimen destroyed world war specifically night april british bombing raid munich severely damaged building housing museum state collection detailed drawings descriptions specimen remain son donated archives smith analyzed photographs specimen viii discovered archives basis photograph lower jaw photograph entire specimen mounted smith concluded original drawings slightly inaccurate oliver suggested composed spines similar analysis rejected subsequent paper held canadian museum nature mid centimeters long beds morocco described russell specimens referred paper mid anterior fragment mid fragment anterior dorsal arch russell stated general locality information provided specimen dated possibly sam housed national snout consisting partial partial fragment described russell specimen centimeters width length stated specimen located algeria age russell believed specimen fragment sam sam dorsal arch sam belonged collection office national des mines described consists partial anterior centimetres length early formation tunisia fragment included partial teeth extremely similar existing material university_of_chicago collection consists mainly narrow connected crest region eyes specimen centimetres long located early beds described scientific literature civic natural history museum milan colleagues described consists snout partial partial centimetres long beds like thought come early partial skeleton recovered beds north_africa described designated specimen reject designation includes dorsal spines complete pedal caudal dorsal ribs fragments skull body proportions specimen debated hind limbs shorter specimen previous demonstrated multiple specimen specimen suggests animal smaller hind limbs previously thought known specimens consist mainly remains scattered teeth include paper described structures tooth teeth tunisia referred specimens und museum und university germany right fragment jaw fragment tooth found lower upper deposit southeastern morocco described teeth morocco highly similar teeth teeth formation tunisia narrow somewhat rounded cross section lack anterior posterior edges characteristic basal assigned teeth formation tentatively referred partial tooth long purchased fossil trade reportedly bed morocco attributed showed wide longitudinal micro structures irregular ridges paper possible specimens possible material belonging reported kenya scientists considered genus junior synonym specimens referred considered following conclusions papers description disputed conclusions considered genus valid function spines function dinosaur sail uncertain scientists proposed including heat regulation display addition prominent feature appear larger intimidating animals structure structure contained abundant blood vessels animal sail large surface area absorb heat imply animal partly warm best lived climates nighttime temperatures cool low sky usually cloudy possible structure excess heat body collect large animals relatively small ratio surface area body compared overall volume principle face far greater problems dissipating excess heat higher temperatures gaining lower sails large added considerably skin area bodies minimum increase volume furthermore sail turned away sun positioned degree angle cooling wind animal effectively cool warm climate cretaceous africa bailey opinion sail absorbed heat bailey proposed instead long spines backs energy storage heat elaborate body structures modern day animals usually serve attract members opposite sex mating possible sails courtship way similar tail speculated males females differed size spine suggest dorsal sail dorsal fins served purpose point basal long legged round crescent shaped dorsal sails dorsal spines form shape roughly rectangular similar shape dorsal fins argue dorsal sail manner employed long narrow tail prey like modern shark employ dorsal fins schools fish bait hall cooperate trap fish certain area fish bills sail possibly reduced rotation lateral force direction opposite slash suggested colleagues specifically wrote anatomy exhibits feature modern long tail resembled shark employed water herd fish oliver strategies sharks employ fish effective concentrated bait ball oliver difficult individual predators achieve cooperate effort fish squid raise sails appear larger slash bills fish turning heads dorsal sail fins stabilize bodies fin extensions enhance accuracy tapping sail reduce rotation lateral force direction opposite slash means prey likely recognize massive trunk approaching predator film footage available online demonstrates hunting strategies sharks exhibited features required combine hunting strategies sail prey efficiently flexible tail neck water stunning injuring killing prey submerged dorsal sail provided strong like powerful movements strong neck long tail performed sharks oliver smaller dorsal sails fins dorsal water volume better accessible speculated smaller effect makes lateral efficient sharks forming trunk axis sail compensated lateral neck tail movements vice versa predation accelerated swimming behaviour reason muscular chest neck reported finally possible sail combined functions acting normally heat aid mating season cool occasions turning intimidating device animal feeling threatened diet unclear primarily terrestrial predator indicated elongated jaws conical teeth raised nostrils hypothesis specialized fish suggested base similarity presence digestive acid fish scales rib cage type specimen large fish known containing including mid cretaceous northern africa brazil direct evidence diet comes related european south american taxa found fish scales bones juvenile stomach tooth embedded south american bone suggests occasionally preyed likely predator possibly cretaceous equivalent large bears biased fishing undoubtedly took kinds small medium sized prey study concluded mechanical data suggests diet closely associated individual size characteristic morphology allowed jaws resist bending vertical direction jaws poorly adapted respect resisting lateral bending reported results ray snout outside communicated space inside snout authors speculated pressure inside space allowed hold snout surface water detect swimming prey species seeing analysis colleagues found oxygen teeth including teeth indicate lifestyles tooth parts found morocco tunisia predators area compared compositions contemporaneous turtles study found teeth sampled oxygen closer turtles compared teeth authors switched terrestrial aquatic habitats compete food large large respectively posture traditionally depicted suggested mid-1970s occasional bolstered discovery relative robust arms mass dorsal bailey open possibility posture leading new hypothesis typical fallen favor posture including hands rotate palm faced ground resting position hand possible shown fossil prints early paper describing new material proposed legs short effectively land reconstruction study based different sized individuals scaled assumed correct proportions john royal college university london expressed new reconstruction cautioned different specimens result inaccurate scott expressed criticism believes legs scaled short don match published lengths responses mark positively received reliable description doubted material assigned belonged previous theories moved water showed like duck water new hypothesis suggests swim instead rivers states dense bones likely hang low water column moved running rivers indian shows traits common partial toes flat barrel shaped body traits usually attributed animals use kind animal thick skin achieve environment lived similar environment thick skinned aquatic mammals possible thick skin achieve kind environment inhabited partially understood covers great deal northern africa region africa preserved dates million years ago study concluded fossils ranged north_africa late cretaceous lived formation egypt contended shoreline conditions tidal flats channels living forests alongside similarly large predators bony fish turtles dry season resorted situation resembles late morrison formation north_america boasts genera weight smaller genera henderson differences head shape body size large north african allow niche seen different predator species found today african popular culture appeared film park iii replacing main antagonist film consulting john quoted saying base ferocious factor length animal lived planet match creature hypothesis actually killer predatory animal retracted statement film portrayed larger powerful scene depicting battle resurrected predators emerges victorious snapping neck fourth film world nod fight skeleton climatic fight near end film long depicted popular books recently information accurate depiction influential skeletal reconstruction based treated upright skull similar large sail having hands addition films action figures video games books depicted postage stamps ones


meaning shield genus dinosaur existed early cretaceous period north_america species named existed understood remains recovered states wyoming montana possibly utah earliest known genus remains found section formation dated million years ago medium sized measuring metres long long tail half body length body smaller modern black mass weighing kilograms extra weight largely extensive covering bony armor including large spines projecting neck description heavily built body length approximately skull triangular viewed rear end wider tapering snout skull measured centimeters width widest point eyes unlike roof skull flat roof skull thick covered flat bony plates tightly fused appear boundaries like ones seen artifact preservation preparation thick triangular projected bone eyes bone eyes typically leaf shaped teeth lined upper lower jaws cutting plant material end skull unknown sharp bony ridge end upper lower jaws seen ridge probably supported tail long nearly half body length skeleton preserved caudal tail missing suggesting true number caudal exceeded tail length like wide body broad shorter resulted arched highest point feet limbs shoulders constructed reinforced support great deal weight american carpenter estimated mass kilograms like covered armor formed bony masses embedded skin discovery skeleton body armor preserved allowed carpenter scientists accurately describe protection parallel rows ran neck axis upper surface tail skin covered small bony separated larger conical arranged parallel rows axis larger plates tightly form structure called shield shield found like large pointed spines lined sides neck increasing size shoulders decreasing size body stopped flat triangular plates lined tail sides pointing decreasing size end tail carpenter originally described neck spines caudal plates belonging single row recently jim reconstructed parallel rows upper row spines pointed backwards upwards lower row pointed backwards bases pair spines pair caudal plates fused greatly restricting mobility neck upper tail classification john described recognized member family family belong characterized certain features skull including lower jaw curves downwards end overall narrower lacked heavy tail clubs like found north_america asia europe evolutionary relationships firmly established genera considered basal younger like analysis carpenter included genera sister clade group containing found belong clade depending taxa characters chosen discovery naming early 1930s famed dinosaur hunter brown collected specimen partial skeleton formation big horn county montana locality inside crow indian reservation brown discovered specimens best preserved skeletons known science includes large armor display american museum natural history new_york_city preserves armor skull missing end snout expeditions 1960s led equally renowned john yale_university museum natural history recovered additional incomplete specimens coined genus include remains discovered expeditions derived greek shield reference bony armor originally named species george corrected spelling conform latin grammar rules despite naming years earlier confusion arose inadvertently published photograph brown published description remains known informally lectures museum exhibits preoccupied genus north american extinct branch modern family glass longer refer dinosaur carpenter colleagues described material large utah discovered member cedar mountain formation called poison strip sandstone contemporaneous formation originally referred possible new species named recent publications carpenter longer refers poison strip animal family recent discoveries include complete skull montana huge skeleton cedar mountain formation utah discoveries published annual society conference prove belong formally published discoveries charles reported presence large dinosaur lower cretaceous rocks british_columbia canada described new species tracks attributed kenneth carpenter examined british prints argued specifically carpenter concluded probably years later large numbers tracks discovered river coal near alberta site considered important track site world earliest known specimens recovered little sheep section formation wyoming montana dated million years ago early cretaceous lived wide rivers drained shallow inland sea north east carrying sediment eroded low mountains west periodic flooding rivers covered surrounding plains new muddy sediments creating formation burying remains animals end times shallow sea expand cover entire region eventually split north_america completely half forming western interior abundant fossil remains coniferous trees suggest plains covered forests grasses evolve later cretaceous early cretaceous variety conifers like narrow adaptation seen today animals selective opposed wide important guild abundant dinosaur time large smaller rare unknown type lived alongside fed sheer number teeth scattered formation testament abundance small basal hunted smaller prey apex predators large mammals species turtles lived rivers lakes swamps providing evidence year round warm climate late fauna dominated varieties huge gave way times early cretaceous fauna like predominant ended large wave asian animals including disperse western north_america forming mixed fauna seen late cretaceous


family medium sized flourished cretaceous period means running greek meaning runner meaning informal usage called term popularized film park types include term directly come emphasize supposed bird like habits fossils found globe north_america europe africa japan china madagascar argentina antarctica teeth giving possibility inhabited australia appeared mid period late stage million years ago survived end cretaceous stage existing million years cretaceous extinction event presence early middle confirmed discovery isolated fossil teeth body fossils found period description distinctive body plan helped theories active fast closely related birds robert illustration john monograph showing fast run influential history body plan includes relatively large skull teeth narrow snout forward facing eyes indicate degree vision like moderately long curved neck trunk relatively short deep like long arms folded body species relatively large hands long fingers middle finger longest finger shortest ending large claws hip structure featured large boot projecting beneath base tail feet bore large second toe tails slender long low lacking transverse process spines 14th caudal known probably covered feathers including large wing tail feathers development mid late 1980s confirmed fossil discoveries represents significant change way historically depicted art film foot like walked hind legs walked toes contacting ground tracks confirm early groups including held second toe ground position fourth toes bearing weight animal called functional enlarged second toe bore unusually large curved shaped held ground retracted walking thought capturing prey climbing trees function especially blade like large bodied predatory possible species possessed toe highly modified parallel second second toes foot held retracted bore enlarged shaped claws tail long tails tail bear bony rod like extensions bony species study proposed features tail base tail single rigid preserved specimen articulated tail skeleton curved horizontally long shape suggests life tail bend substantial degree flexibility proposed tail running air diamond shaped fan feathers preserved end tail aerodynamic rudder powered flight flight size small medium sized ranging metres length case metres grown larger specimens young university collections belonged individuals reached long await detailed study large size appears evolved twice measured metres long possible lineage giant represented isolated teeth found isle england teeth belong animal size appear belong judging shape teeth primitive described smallest evidence combined small size primitive relatives indicates common ancestor birds called ancestral small length grams mass feathers large body evidence showing covered feathers fossils preserve long feathers hands arms tail shorter like feathers covering body fossils preserve actual impressions feathers preserve associated bones long wing feathers attached life overall feather pattern looks like known definitive evidence feathers reported china fossils found feathers covering bodies fully developed wings shows evidence second pair wings hind legs direct feather impressions possible fine sediments fossils found rocks evidence feathers presence attachment points wing feathers possessed birds found showing forms feathers despite impressions having found light likely larger ground dwelling bore feathers birds today retain plumage relatively large like known retained feathers scientists suggested larger lost covering discovery feathers specimens cited evidence members family retained feathers recently discovery established presence coat relatively large additionally animal displays large aerodynamic wing feathers tail spanning fan unexpected traits offer understanding large larger species evidence feathers albeit indirect form function currently disagreement function enlarged second toe john described interpreted blade like weapon like toothed cats powerful kicks cut prey adams suggested large interpretation killing weapon applied manning argued instead served hook elliptical cross section instead previously inverted shape manning interpretation second toe climbing aid bigger prey stabbing weapon compared noted bird species inflict injury large second toe claws millimetres long cited saying arm man studied documented attacks found human dogs killed evidence animals use claws defend attack threatening animals displays threat display enlarged second toe uses tear apart small prey items manning colleagues attempted test function similarly shaped claws analyzed mechanics stresses strains distributed claws limbs ray imaging create dimensional map comparison analyzed construction modern predatory bird eagle owl found based way stress conducted ideal climbing scientists found tip gripping instrument curved expanded base helped transfer stress loads evenly manning team compared foot modern birds mammals previous studies shown corresponded lifestyle animal animals strongly curved claws certain shape tend claws indicate ground dwelling lifestyles claws degrees range climbing animals claws studied fell climbing range peter commented manning team study stating small primitive likely tree climbing explain later gigantic retained highly curved claws large climbed trees speculated giant adapted exclusively prey published study toes showed range motion compatible excavation tough insect nests suggested small small partial larger genera ability catch prey residing insect nests test strong claws activities denver colleagues suggested new method taken smaller prey model known prey restraint model predation proposes killed prey manner similar extant birds prey quarry pinning body weight gripping tightly large shaped claws like begin feed animal alive eventually died blood loss organ failure proposal based primarily comparisons morphology proportions feet legs groups extant birds prey known predatory behaviors found feet legs closely resemble eagles hawks especially terms having enlarged second similar range motion short foot strength similar method predation consistent aspects anatomy unusual arm morphology arms exert lot force likely covered long feathers balance atop struggling prey animal stiff tail jaws thought colleagues comparatively weak useful eating prey alive useful quick forceful dispatch prey predatory adaptations working implications origin group behavior fossils uncovered small groups near remains larger dinosaur interpreted evidence hunted coordinated packs like modern mammals found evidence conclusive subsequent study published suggests actually displayed disorganized behavior modern including birds closest relatives display minimal cooperative hunting instead usually solitary hunters drawn previously killed conflict occurs individuals species example situations groups dragons eating largest individuals eat attack smaller dragons attempt feed smaller animal dies usually information applied sites containing pack hunting behavior appears somewhat consistent like feeding strategy skeletal remains found sites missing parts eaten study presented evidence idea animals hunt scientists described known extensive china addition confirming hypothesis held retracted ground large sized species showed evidence individuals equal size moving shoreline individuals spaced meter apart retained direction travel walking fairly slow pace authors paper describing interpreted evidence species lived groups clearly represent hunting behavior idea groups hunted according authors ruled flying ability fly suggested species originally classified bird found later studies capable powered flight indicated long evidence long flight feathers built evidence bore strong necessary flight concluded given adaptations probably fly clumsy air modern birds species capable developed wings fore hind limbs study suggested wings functioned like split level likely employed style launch perch downward shaped curve lift land tree tail hind wings helping control position speed found basic requirements sustain level powered flight addition close relative thought based presence wings similar limb proportions considerably larger animal size wild turkey largest known flying species display partial flight capacities young species bore longer arms robust pectoral adults similar seen implying capable flight young lost ability grew possibility capable powered flight brought times studies occurred preserves wing feathers shaped particularly bird like opposed longer wider spanning forms like fused plates size short arms unlikely capable powered flight importance modelling regard stressed suggest relatively close flying ancestors capacity wing assisted running senses comparisons rings modern birds reptiles indicate including nocturnal predators active day short intervals discovery plumage cast doubt genus modern birds plumage known nocturnal studies reveal similar size non modern birds acute sense smell turkey vulture probably reflecting importance sense daily activities finding food bruce published study examining evidence stress implications behavior stress caused repeated trauma singular events likely caused regular behavior types injuries researchers found like caused stress hand discovered course study stress hands special significance compared found feet stress obtained running migration hand injuries contrast likely obtained contact struggling prey classification relationship birds share features early birds clade precise nature relationship birds undergone great deal study relationship changed large amounts new evidence available late mark colleagues analyzed large survey fossils produced tentative result closely related birds distant suggested relative colleagues utilized work including new characters better fossil evidence determine birds better thought cousins consensus concluded evidence determine fly evolved ancestors alternative theories led researchers argue better classified birds feathers birds traditional definitions word bird based possession feathers scientists lawrence argued calling like bird feathers stretch word past useful meaning schools researchers proposed actually descended flying ancestors involving flying ancestor called birds came george usually credited author work gregory paul pointed numerous features skeleton interpreted evidence entire group evolved flying ancestors like case larger like modern paul suggested actually closely related modern birds paul placed closest relatives found primitive colleagues cited basal position feather wing features evidence ancestral case larger terrestrial having lost ability later evolutionary history described probable junior synonym reconstructed fossil wings argued powered passive later issued revised reconstruction agreement researchers like larry martin believe martin asserted decades birds unrelated changed position agrees closest relatives martin believes birds birds evolved non species called classified described anatomy preserved specimen determined anatomy like non previously understood specifically found primitive hyper second toe phylogenetic analysis produced controversial result closer making taxon suggested ancestral able fly lost ability butler criticized work grounds challenge alternative scenarios came turner colleagues described new found basal primitive member primitive short arms ability turner flight evolved points suggested ancestral fly based analysis suggests ancestral condition non expanded revised study incorporating recent finds recovered like primitive member clade appears suggest earliest members clade capable flight 1960s classified group clade named initially based primarily presence retractable second toe known present primitive birds coined russell defined clade closer birds early 2000s consensus closely related turn sister taxon closest relatives birds turner conducted phylogenetic analysis characters scored taxa found recent studies cast doubt hypothesis closely related birds robust study characters scored taxa found possibly closely related birds forcing remain required extra steps analysis making result likely originally defined animals closer birds specific reference synonym closer birds taxonomy authorship family credited william matthew brown erected subfamily family containing new genus frequently shift content based new analysis typically consist following groups number assigned particular subfamily poorly preserved placed phylogenetic analysis section phylogeny basal relative primary subdivisions example primitive known falls outside named sub group basal subfamily found enigmatic group poorly supported subfamily possible members belong outside larger ground dwelling members like strong flight adaptations probably large member group small developed wings evidence attachment points flight feathers likely fly primitive clade group includes smallest adaptations living trees known skin impressions hail group extensive covering feathers developed wings like species capable active flight subfamily traditionally included discovery lent support grouping inclusion uncertain usually found consist medium giant sized species generally box shaped generally narrower following classification genera follows table provided noted family subfamily subfamily subfamily subfamily history genera phylogeny defined clade paul inclusive natural group containing defined usually defined species closer groups namesake sub example defined clade closer sub clade converted subfamily colleagues coined subfamily avoid perceived issues traditional family group taxon group found lie outside proper offered revised definition sub group containing ensure fall erected subfamily usage appeared online database formally published extensive analysis conducted turner supported follows analysis robert david larry martin peter robert updated data working group technical diagnosis diagnosed following features short shaped form boundary shelf lateral process contacts raised dorsal modified pedal digit caudal spanning presence popular culture gained attention featured prominently steven_spielberg film park dimensions film larger largest members genus robert recalled disappointed dimensions adding soon named size depicted larger gregory paul book predatory world considered species species taxonomic opinion widely followed


meaning king derived sanskrit king genus dinosaur unusual head crest bones discovered geological survey india excavated river valley district india find announced new genus dinosaur american indian scientists august paul university_of_chicago jeff wilson university_of_michigan worked american group study river fossils fossils represented partial skeleton new species means valley bones found region state description member group predators known lived africa india madagascar south_america closely resembles contemporary madagascar island separated indian million years earlier found phylogenetic analysis characteristics described subfamily including configuration nasal bones possession growth frontal bone distinguished genera single nasal frontal horn elongated proportions holes upper rear skull form principle bones hip feature transverse ridge separating shelf hip joint identified partial skeleton including skull backbone hip bones parts hind legs tail specimen serves type specimen genus species measured long preserved skull shows bore distinctive low rounded horn nasal frontal bones history discovery river central india drains valley east west rift valley eventually arabian sea traveling dinosaur bones reported valley late 19th century including belonging history fossils named begins geological survey india mapping mission workers cement quarry showed smooth ball like limestone structures quarry balls turned eggs found limestone bed containing eggs layer coarse sandstone abundant fossil bones years division western region collected large numbers bone fossil fragments precisely mapped area fossils taken division identification supervision cleaned skeletal parts dorsal caudal thigh bone upper arm bones leading publication multiple research papers activity memorandum understanding signed university research fossils continued american scientists sponsored american institute indian studies new delhi national geographic society americans paul jeff wilson started reconstruction collection dinosaur bones gathered team scientists detailed study maps prepared earlier able reconstruct partial skull left right hip bones interpreted skull horn resembling found madagascar fossils found near collected fossils include partial skull limb bones hip bones formally described fossils described belong genus charles alfred described year specimens including bone armor found later shown wilson suggested lost similarly stout discovery lead additional information evolutionary relationships previously described specimens india mainly isolated bones press conference held discovery stated discovery examination global experts important help adding current knowledge dinosaur belonging family predators adding new angle indian known indian peninsula time alive indian recently separated rest moving north evolved direction similar madagascar south_america animals descended common lineage found formation rock unit represents forested setting rivers lakes formed episodes volcanic rocks known traps fossils known river lake deposits quickly buried volcanic flows formation include recorded formation presence fungi indicates leaves eaten lived tropical subtropical climate scientific study similarities egg taxa suggested close relationships supports existence terrestrial connection fauna india europe cretaceous areas india cultural significance order educate people extinct forms life geological survey india installed life size models regional office installation presented appropriate setting representations plants existed era displayed limb bones eggs fossil eggs collected restored skull prominent exhibit indian museum interested royal family dinosaur closely watching efforts fossils efforts promote dinosaur tourism order showcase millions years dinosaur heritage set small museum hotel ride river adventure launched india ride inspired park ride located universal parks


genus dinosaur late type species named described german thought primitive member recent analyses find derived close relative north american morrison formation fossils found formation dated late early ages million years ago hundreds bones unearthed german expeditions german east africa complete skeletons known remains provided nearly complete picture build animal generally measured metres length adult weighed tons walked straight small elongated head bite plant material large gut probably double row small plates running neck plates gradually merged spikes hip tail longest spikes tail end actively defend animal long spine shoulder thigh bones come different types suggesting sex larger stout description small typical body characterised small head long neck short long long horizontal muscular tail typical traits included head powerful build erect pillar like array plates spikes running sides mid line animal single complete tooth known published later tooth bearing bone lower jaw found bears emerging tooth tooth fragments recovered matrix sticking bones deep identical shape albeit smaller similarly tooth typical tooth small widened base vertical grooves creating ridges size posture smaller large total length composite skeletal mount museum berlin germany tip snout tip tail slightly half length tail larger single elements found animal probably attain total length gregory paul estimated weight metre long seven kilograms estimate long composite mount museum berlin basis virtual skeleton model varied body mass tonnes short tons depending reconstructed tail long tail results position center mass unusually far animal rests hip position usually seen straight opposed typical indicating straight vertical limb position powered massive thigh muscles attached long support animal robust took distinguishing features distinguished members number characters provided revised diagnosis updated list distinguishing traits notably spines blade like upper extensions tail run sub parallel tail point backwards usual direction middle tail vertical hook shaped point forward typical dorsal arch twice high body completely occupied extremely canal process blade widens outer furthermore unique combination traits unique transverse processes extensions tail present eighth series transverse processes tail rod shaped narrow bases touch plate formed fusion processes bones pointing tail shape inverted length equals greater armour typically extensive bony structures skin covering including small plates probably located neck anterior trunk spikes shapes spikes elongated specimen having bone core length millimetres plates section middle modified spines spikes plates likely covered horn aside exceptions found close association skeletal remains exact position uncertain pair closely spaced spikes found articulated tail tip number spikes found apparently regularly spaced pairs path articulated tail grouping dermal armour elements distinct types recognised apparently continuous change shape shorter plates gradually merging longer pointed spikes rear suggesting distribution entire body pairs type found mirrored left right versions probable types distributed rows animal marked contrast better known north american row plates neck trunk tail rows spikes tail tip type spike differs strongly slightly having broad base bone morphology classic placed blade recent place shoulder similarly shaped spike known existed shoulder chinese discovery species fossils discovered german expedition recognised belonging expedition leader july described german coined comes greek meaning sharp point meaning added specific denote africa onwards remains uncovered middle beds quarry upper beds field seasons german expedition found bones belonging individuals destroyed second world war today remaining material housed museum berlin roughly remaining specimens museum institute university houses composite mount roughly original bones complete individuals found material discovered association including nearly complete tail hip dorsal limb elements individual form core mount museum mount dismantled museum renovation mounted improved pose research casting international material including spine thought destroyed world war supposedly lost material later found basement type sole accepted species named fossil material wyoming named charles classified north american species action accepted community assigned genus differing having elongated tail spikes structure type specimens type locality original description designate specimen detailed systematic position picked complete partial skeleton today material includes nearly complete series tail included mounted skeleton museum berlin germany type locality near hill unaware defined peter selected dorsal specimens material figured description definition valid selection priority clarified material known bones discovered concluded german excavations correct naming controversy soon description controversy arose similar rules biological nomenclature forbidding animals given renamed pointed tail hungarian renamed genus lance bearing year renaming necessary priority different pronounced soft replacement names remains valid genus junior objective synonyms phylogeny assigned confirmed modern analyses noted far inclusive concept consecutive concept caused 1980s seen typical primitive placed derived higher position evolutionary tree derived traits include long process long rows plates spikes study recovered basal position shown earlier analyses shown closer tree basal traits include prominent skull teeth seven denticles margin shoulder spine feeding like fodder barely large theory diet holds low level eating foliage low growing fruit non flowering plants capable eating heights possible rear reach vegetation higher trees centre mass close hind limbs animal potentially support stood likely capable allowing vertical trunk rotation degrees tail probably fully lifted blocking movement rest ground provided additional support precisely flexibility certain support actually provided stiff function leg suggested robert thomas pose fed heights defense tail caudal highly mobile possibly swing arc degrees covering entire half circle swing speeds tail end high continuous rapid swings allowed spikes slash open skin attacker stab soft tissues break ribs facial bones directed blows resulted sides spikes legs blunt trauma attacks crippled small medium sized damage large ones earlier interpretations defensive behaviour included suggestion animal charged rear run attackers spines way modern likely stood erect like animal adopted posture defending neck flexible allow sight predators reach sides body snout look addition posterior position center mass rapid meant animal quickly rotate pushing sideways arms keeping tail pointed attacker quick predator tail base impact speed lower tail passed neck upper body unprotected tail swings successful predation required group hunting compared robust spikes thinner spikes greater risk bending growth study concluded bone indicated higher growth rate reported view relatively rapid deposition highly bone larger general rule larger grew quicker smaller ones sexual differences proportions size led holly realize probably showed sexual consisted robust occurrence ratio robust likely higher percentage animals females ratio considered reasonable assume society males female behaviour found problem posed ratio multiple specimens studied died place probably sudden mass death represent single herd contemporary population results distorted greater chance robust animals getting discovered earlier study suggested individual difference rib count indication females extra pair ribs having connected addition subsequent lived late formation main located middle beds dating upper remains found upper beds dating boundary dated million year ago ecosystem primarily consisted types environment shallow like marine environments tidal flats low coastal environments inland environments marine environment existed fair weather wave base barriers appeared little change levels experienced tides storms coastal environments consisted coastal lakes ponds pools environments little vegetation probably visited dominated conifers overall late climate subtropical tropical seasonal rains pronounced dry periods early cretaceous humid beds similar morrison formation north_america marine fellow like organisms inhabited included cephalopods sharks fish small mammals like


meaning hooked greek incorrectly translated griffin latin genus dinosaur lived million years ago late cretaceous late late stages north_america named species known dinosaur park formation alberta canada formations united_states lower medicine formation montana formation utah similar years thought synonyms known numerous skeletons skin impressions scales projecting easily distinguished narrow nasal described similar roman nose species sexual identification combat individuals species large meters feet long preferred river settings description typical size shape best specimens genus nearly complete type specimen regarded synonym came animal meters feet long specimen best example skin impressions showing dinosaur different types shaped upwards centimeters long inches flank tail uniform scales neck sides body structures flattened sides longer tall found single row named species differ details skull lower jaw prominent nasal arch found genus formed paired nasal bones profile view rise rounded eyes reaching height tall highest point skull skeleton known great detail making useful point reference skeletons classification older references member subfamily hollow head general term arched thought fall group described known nickname subfamily coined jack larger revision promoted family status use rough equivalent issue relationships complicated lack resolution compares time main differences location alberta montana utah new_mexico age comes slightly younger rocks skull known lacking bones eyes similar following based phylogenetic analysis conducted wagner showing relationships discovery history based specimen skull partial skeleton collected george known dinosaur park formation alberta red deer river specimen described named lawrence shortly drawing attention unusual nasal crest years earlier brown collected described partial skull new_mexico named skull missing snout eroded fragments brown restored known flat headed believed unusual pieces evidence compression description provided evidence different type skull configuration skull redone nasal arch brown charles proposed idea reflected william parks naming nearly complete skeleton dinosaur park formation left genus direct comparison hindered fact type specimen missing skull shape nasal arch seen publication influential wright monograph sealed question nearly years favor reviews beginning 1990s called question identity limited material comparison separated temporarily situation confusing old suggestions authors including jack hypothesis common late 1970s early 1980s appears popular books known work illustrated encyclopedia uses canadian material identifies mounted skeleton photo new combination partial skull skeleton second complete skeleton montana fallen literature changed position use print current thought known material distinguished differences upper arm research revealed presence second species slightly older rocks montana classic alberta based parts skeleton collected american museum natural history known material described specimens considered derived species new material formation utah grand staircase national monument includes skull partial skeleton represent species skull robust species enlarged upper margin lower jaw based new species greatly expands geographic range genus second lightly built species present multiple species known formation represented remains larger northern counterparts species named species recognized today type species late age upper cretaceous dinosaur park formation alberta canada thought species formation known synonym differentiated size nasal arch larger closer eyes form upper arm longer robust complete known skeletons assigned late early lower medicine formation county montana usa known partial skeletons individuals nasal arch prominent like farther forward snout teeth derived reflecting like characteristics informal early unused species known skull partial skeleton utah listed second list new species international institute species exploration dubious considered possible species following rejected edition dubious eating variety plants skull special joints permitted grinding motion analogous teeth continually replacing packed dental batteries contained hundreds teeth relative handful use time plant material broad held jaws cheek like organ feeding range extended ground like bird dinosaur park formation appears existed duration time rocks formed formation laid recorded change marine influenced conditions absent upper formation present instead known lower formation include hollow preferred river related settings nasal arch distinctive nasal arch like modifications variety social functions identification sexes species social ranking functioned tool broadside pushing social contests air flanking visual signaling arch specimens suggesting covered thick skin extension utah dating indicates formation deposited million years ago stage late cretaceous period late cretaceous period site formation located near western shore western interior large inland sea split north_america west east plateau lived ancient dominated large channels abundant wetland swamps ponds lakes bordered highlands climate wet humid supported abundant diverse range organisms formation contains best continuous records late cretaceous terrestrial life world shared like like armored present formation included sharks rays frogs turtles variety early mammals present including


pronounced originally renamed spelled species plant eating dinosaur genus state dinosaur state missouri official state bones species discovered later known dinosaur site near allen missouri remains site marked known discovery dinosaur remains missouri ones found thought later study determined duck billed dinosaur bear likeness ducks bills species bones found dinosaur site housed washington institution characteristics species estimated small teeth weighed short tons elephant today stood feet tall stretched feet head tail lived southeast missouri age late cretaceous period species teeth indicator vegetation missouri time coarse tough charles whitney dan stewart described caudal retrieved missouri journal report writing caudal longer wide ends having concave central areas decorated ridges depressions surrounded flattened peripheral border posterior ends thirteen adult tail bones appeared consecutive smallest millimetres long discovery remains discovered county missouri members family digging subsequently collected stewart later nicknamed dinosaur dan stewart missouri geological survey examining clay near allen came boy led family work digging according stewart property owner found unusual bones digging saved found feet deep overall depth feet black plastic clay stewart reported discovery institution bought remains thirteen dinosaur tail later purchase cow bones unknown type recovered site additional given friend bones analyzed species originated incorrectly identified site bones found largely untouched excavations restarted remains fish turtles plants found including teeth belonging member parts including dental remains jaw found variety remnants found site suggest large body water existed close area geology dig site guy louis missouri currently working dig site said pretty miracle dinosaur bones found missouri state soft soil resulted deterioration prehistoric remains remains found damaged erosion processes missouri lies rocks eras site situated rock stewart found bones assigned study origins clay southeastern portion able conclude region lies deposits upper cretaceous period sediment time period eroded away family dug ultimately abandoned unable provide water southwest farmhouse atop body limestone farmhouse located near steep valley sitting atop remains terrace layer clay bones found described stewart feet thick situated feet yellow brown clay gravel surface dense mass limestone dig site located atop formation land home dig site sits atop sandstone lower period canadian located section affected erosion filled sandstone debris addition region impacted frequent leading combination rocks different periods result difficult create accurate map area identification stewart described species january issue journal classification error positive evidence deemed species process elimination left possibilities dismissed saying specimen possible exception cope presence posterior end appear sufficient member species called renamed later year stewart preoccupied died soon bones left untouched decades moved genus time john late 1970s bruce traveled site reading report 1950s able purchase property member family 1980s test excavations performed david barbara leading conclude actually thomas suggested species state dinosaur designation january bill introduced missouri house_of_representatives state representatives rod jason originally proposed state dinosaur specific house conservation natural resources committee settled bill sent missouri general_assembly passed missouri house_of_representatives march vote missouri senate vote approved governor bob july bill house bill went effect august missouri sixth state designated official state dinosaur following colorado maryland new_jersey texas wyoming district_of_columbia local impact representatives county businesses local government officials met effort generate revenue came dinosaur centered tourism campaign businesses contributed creation billboard interstate advertise county home missouri dinosaur county museum natural history displays bones found said exhibit species attracted tourists parts united_states museum says designation state dinosaur resulted visitors march construction size model completed placed display museum speaker missouri house_of_representatives sponsored dinner event state legislators celebrate completion exhibit march year project directed charge excavations excavation site permanent museum exhibit feature species opening exhibit mentioned hoped dig site state park day currently excavation conducted missouri dinosaur project site covered prevent water flowing dig material dig site near allen currently private ownership location missouri dinosaur bones found