meaning great greek meaning big tall great meaning genus large meat eating middle period stage million years ago southern england fossils areas assigned genus certain remains come late middle earliest possible fossils genus came limestone formation lower discovered 17th century originally described robert plot roman war elephant biblical giant scientific given 18th century created richard considered valid today genus non dinosaur named type species named genera richard owen based owen directions model crystal palace greatly increased public interest prehistoric reptiles subsequently species classified genus originally known 20th century discovered today understood additional species directly related true species complete skeleton found unclear build investigated gigantic metres length owen concluded longer metres standing upright legs thought modern scientists comparing direct relatives able obtain accurate picture seven metres long weighing tonnes walking stout horizontal balanced horizontal tail short robust large head equipped long curved teeth generally robust heavily animal discovery naming dinosaur apart modern birds described scientific literature bone recovered limestone formation limestone quarry sir thomas gave fragment robert plot professor chemistry university_of_oxford curator museum published description illustration natural history illustration dinosaur bone published plot correctly identified bone lower large animal recognized large belong species known living england concluded roman war elephant later giant human mentioned bible bone lost illustration detailed identified argued possible bone given species applied extinct dinosaur plot bone book richard called apparently comparing appearance pair human pointed similarity modern species called parts coincidence founder modern taxonomy eighteenth century merely devised system naming living creatures classifying geological objects book applying system curious stones found england according deliberately nomenclature fact indicated possible type specimen new biological genus according rules international code nomenclature principle priority published understood stone actually represent pair irrelevant merely fact subsequent literature meant removed competition priority states considered valid invalid forgotten death friend william submitted petition international commission nomenclature formally suppress favour wrote supposed junior synonym ensure priority executive secretary time philip consider petition concluding term published merely label illustration constitute valid creation new stated evidence intended furthermore partial incomplete definitely referred different contemporary research eighteenth century number fossils british collections quickly increased according hypothesis published science historian robert william partial lower jaw acquired october christopher added collection anatomy school christ church college early nineteenth century discoveries john reported find bones giant quarry layers currently considered limestone formation dating mid stage period bones apparently acquired william professor geology university_of_oxford dean christ church studied lower jaw according bought know animal bones belonged napoleonic wars french comparative visited oxford realised giant like creature studied remains friend william referred huge joint article included intended provide scientific names gigantic like creatures known time remains found near named seen land dwelling animal british devised greek large year publication failed occur physician james announced illustrating teeth revealing creature feet long feet high generally considered naked urged continued work subject letting later wife mary provide drawings bones basis illustrating finally february meeting geological society london described complete specimen formally announced descriptions bones transactions geological society constitute valid publication non dinosaur genus named remains certainty scientifically described material available consisted specimen piece right lower jaw single erupted tooth posterior dorsal anterior caudal rib rib piece bone lower second aware belong individual articulated represented individuals described fossils formed series modern standards single specimen selected serve type specimen based chose famous lower jaw deep taller typical reptiles bones interpreting bone identified organism giant animal belonging time seen including placed new genus repeating estimate largest pieces described indicated animal metres long life etymology provided specific uncommon early nineteenth century genus seen essential concept ferdinand von gave dinosaur complete later authors considered year later included geological survey southeastern england assigned species current valid recently form variant published christian von erroneously ascribed von original priority later finds worked continued produce fossils single bones skull bones rare roger counted total specimens slate minimum seven individuals contentious material represents single taxon julia day paul claimed present based small differences favoured idea concluded differences fragment specimen assigned thomas robert thomas claimed represented member thought separate species belonging pointed fragment basically indistinguishable known fact compared authors apart finds limestone formation hugh referred remains found older limestone formation dating early thirty single teeth bones age makes problematic assume identity establish relevant differences remains found site new park quarry affirmed reference species site quarry material contained bone clearly trace fossils referred famous group found limestone quarry kilometres northeast oxford thought possibly left set lawn oxford_university museum natural history track accelerating walking running according tracks traits unique certainly limited finds age finds sites outside england especially france nineteenth twentieth century referred considered clearly different establish identity fossils philippines identified nature american john suspected belonged description early reconstruction given considered thought animal capable swimming sea walking land generally mind resembled gigantic understood form head legs held upright original description repeated size estimate feet long weight seven foot tall elephant based remains present oxford naming new visit fossil collection lecture announced acquired fossil enormous magnitude twice long described today known belonged time men assumed bone belonged taking account effects heavier animals having relatively bones forced printed version lecture estimate maximum length seventy feet existence posed problems christian typically held suffering death come world original sin presence gigantic pre phase history rejected usual solution originally peaceful claimed played beneficial creation ending lives old ill animals diminish aggregate animal suffering fashionable england concept species general progressive development time expressed work robert chambers reaction august richard owen lecture british association advancement science claimed certain prehistoric groups attained level present mammals implying progress owen presented examples higher level reptiles model entirely abandoned upright stance high meant earlier size estimates exaggerated simply adding known length instead owen arrived total body length thirty feet printed version lecture published owen united reptiles separate group original benjamin commissioned build life sized concrete model exhibition prehistoric animals crystal palace park remains day worked direction owen statue reflected owen ideas like sculpture crystal palace park shows conspicuous shoulders suggested inspired set high spines acquired owen early 1850s today seen separate genus owen referred models exhibition created general public awareness time england ancient reptiles existed like challenged find small animal significance gigantic forms denied near oxford type specimen discovered reasonably intact skeleton large clearly shortly john phillips created public display skeleton oxford arranging known bones held cardboard sheets natural position 1870s north american discoveries large like confirmed oxford_university museum natural history display contains specimens original description modern description diagnosis decades discovery seen researchers definitive typical large dinosaur result began function taxon large small europe assigned genus slowly changed 20th century common restrict genus fossils found middle england restriction occurred late 20th early 21st centuries researchers dan suggesting slate fossils belonged possibly directly related species dinosaur subsequent research confirm hypothesis genus species generally regarded limited taxon having produced lower jaw furthermore researchers failed find characteristics jaw distinguish relatives mean genus comprehensive study roger colleagues related analyses published subsequent years overturned previous consensus identifying unique distinguishing characteristics lower jaw separate distinguishing traits lower jaw established longitudinal groove outer surface wide tooth enlarged seen straight expanded jaw tip plates reinforcing teeth lower jaw tall concluded assume slate material represents single species additional distinctive traits observed parts skeleton low vertical ridge outer hip joint shows parallel vertical grooves bony skirts shafts thick touch forming flat surface boss present lower outer shaft rough surface underside second angular longitudinal keel ridge upper connected groove second middle edge forms thin crest skeleton finds bones recovered complete skeleton found details physical appearance certain known material published size traditionally texts following owen estimate body length thirty feet metres lack articulated dorsal series makes difficult determine exact size david bruce norman thought seven metres long gregory paul estimated weight tentatively tonnes given seventy centimetres long trend early century limit material inspired lower estimates uncertain identity paul stated metres long seven heavy year claimed medium sized largest middle specimen millimetres long indicate body weight method anderson method mammals tends masses furthermore specimen length eighty centimetres general build general typical build large horizontal balanced long horizontal tail long strong forward facing weight bearing toes relatively short exceptionally robust probably carrying large elongated head bore long dagger like teeth slice flesh prey skeleton highly indicating robust muscular animal lower leg heavily built close relative skull lower jaws skull poorly known discovered skull elements generally large relation rest material indicate large head known making impossible determine snout profile curved rectangular snout suggested fact branch short depression smaller non piercing seen probably bears thirteen teeth teeth relatively large crown length seven centimetres teeth supported tall triangular plates cutting edges bear eighteen tooth formula probably bone pierced large direction probably air sac nasal bone level known represent separate lower jaw robust straight view expansion jaw tip suggesting lower jaws pair narrow traits identified later result damage unique combination traits present wide longitudinal groove outer shared small tooth channel row plates closed fifth tooth position onwards number teeth probably thirteen fourteen preserved damaged specimens tooth plates smooth inner sides vertically combination shown bony shelf ridge outer oval opening present jaw joint posterior second anterior lacking column exact numbers unknown column probably divided neck thirteen dorsal tail common basal slate material contains neck single broken anterior known new park quarry specimen reveals large internal air chambers heavily large excavations sides rear strongly concave neck ribs short dorsal slightly convex concave rear deeply ridge underside representing total height lower rib joint process rear dorsal according slightly hollow secondary joint processes forming complex having triangular transverse cross section height dorsal spines rear unknown high spine tail new park quarry material specimen suggests presence crest hip area spines form plate fused rounded second normally fourth having ridge excavations sides tail slightly hollow rear excavations sides longitudinal groove underside spines tail basis thin tall representing half total height skeleton short wide length times minimum width rare basal trait curves slightly rear view lower outer blade broad ridge present running shoulder joint gradually merges blade surface middle edge length forming slightly protruding crest constitutes half shoulder joint oriented sideways known specimens fused lacking visible oval bone plate longest attached pierced large oval usual boss attachment upper arm muscles lacking robust strongly expanded upper lower ends specimen length millimetres shaft equals half total length head continues rear large bosses forming massive bone plate outer shaft large triangular crest present attachment major covers upper half shaft length apex positioned low extremely robust absolute size heavily built known member known specimen length millimetres minimal shaft millimetres straight view large attachment process radius wrist hand unknown long low convex upper profile blade triangular short end small point separated notch rear blade roughly rectangular outer concave serving attachment surface main thigh muscle hip joint surface low vertical ridge present conspicuous vertical grooves rear blade excavated narrow deep trough forming bony shelf attachment outer rear blade match inner seen separate blade view visible places corner outer small surface extreme rear tip outer rear blade bone straight bones halves connected narrow bony skirts originated high position rear continued downwards point low shaft shaped view showing transition point rough boss outer edge shaft process present form low ridge separated shaft notch ridge continues exceptionally thick bony skirt inner rear shaft covering half length end shaft skirt gradually merges shaft eventually ends foot convex lower profile straight view seen direction head perpendicular shaft seen greater relatively wide separated robust lesser base lesser low present lower end distinct groove separates upper inner groove rough area present continuing longitudinal ridge typical trait relatively straight slightly curving shaft progressively rear resulting generally oval cross section eighth length lower end shaft covered vertical branch foot second fourth known bone elements connected weight bearing toes straight robust showing pits lower sides clear lower end resulting flexible joint allowing horizontal movement inner carries unique ridge fits groove outer second causing connection phylogeny assigned assuming close affinity modern owen genera placed prince charles coined separate family type genus long time precise relationships remained vague seen primitive member group large united late 20th century new method allowed time exactly close taxa related matthew showed sister species giving living europe period million years ago hunted repeated descriptions nineteenth early twentieth century hunting earliest named forests covered continent known inaccurate skeletons found younger early cretaceous formations specimens belonging lower middle gloucestershire material outside formations england referred lived alongside possibly remains found alongside fossils concluded size common distribution apex predator habitat saw absence french indication live island limited london rib figured sir richard owen swollen spot near base process swollen spot appears caused healed fracture located point articulated species synonyms later nineteenth century seen typical dinosaur remains found deemed sufficiently distinct warrant separate genus single teeth classified began function taxon sort default genus eventually contained species non dinosaur genus dubious validity twentieth century practice gradually discontinued scientists discovering mistakenly classified different animal group older literature felt forced choosing default generic generic published named added letter named new genus create synonym von published article new species paper genus times time created new synonym later walker created time accidentally replaced species named 19th century joseph renamed frightening genus based teeth friedrich august named based probable late tooth found near specimen named insignificant based tooth found near normandy having height tooth remained description provided today considered member specimen having destroyed bombardment jean named based specimen tooth found near collection peter today referred seen member named remains found near fossils possibly belonging henry science teacher published named late possible dinosaur teeth found near blunt predatory harry named possible teeth found austria specific refers possibly member named based specimen found near netherlands specific honours jacob van separate genus friedrich von named remains found teeth early cretaceous proud genus based specimen tooth early cretaceous named specific separate genus joseph ferdinand renamed today renaming generally rejected richard named specific owen based series early cretaceous specimen separate genus edward cope renamed marsh largely motivated desire rival charles marsh found acceptance charles jean named based remains late cretaceous found madagascar separate genus generic cope denote preoccupied marsh provided replacement henry partisan cope rejected replacement renamed cope species named 20th century baron renamed cope publication renamed probably represents fossil material named based teeth found kingdom hungary specimens later lost represents louis named based manual found near belgium reported result sources mistake indicate year date naming represents member member von renamed owen based presently lost partial today seen member richard named based tooth specimen today seen member arthur smith named based skull middle specific collector lewis bradley separate genus named enormous based specimen long tooth german east africa possibly represents large member saw member von renamed today genus generally seen valid publication von named additional species specific william kitchen parker based leg bones late cretaceous separate genus second named based leg bones middle von separate genus based teeth algeria named separate genus von mistake named species intending base remains morocco referring teeth implies junior objective synonym von named specific richard based specimen implies junior objective synonym likewise seen publication von named based teeth found near specific seen fossil material probably representing member work von mentioned synonym named book type specimen differing earlier names synonyms samuel named species exceptional based complete skeleton found arizona early specific honours john separate genus albert named based series found near layer formation morocco probably represents member alfred renamed based lower jaw found near nice authority von originally considered present opinion confirms named based teeth found near portugal today seen member renamed based tooth predatory found del named named unexpected discovered site remains based specimen tooth found argentina represent member steel named species firstly renamed secondly renamed owen genera today seen identical michael renamed today scientists seen directly related type species publication named western based skull fragments middle separate genus del named based specimen tooth found province possible large named species found earlier mentioned species unpublished implying initially invalid publication contain descriptions names species named group second edition mistake spelled second species renamed based specimen tooth india possible member gregory paul renamed change found acceptance renamed formally impossible change named species unnamed george new combination mistake renamed mentioning species list seen publication listed renamed based tooth found near member peter renamed newton based left lower jaw specimen found basal senior synonym specific refers latin wales probably represents member predatory species list complex naming history summarised formal species list naming authors directly mentioned changed placed authors changed mentioned list indicates described identifiable generic level fallen use different genus mentioned sign today considered valid listed reassigned species literature phylogeny journal systematic


meaning forms clade includes family basal relatives lived beginning period end cretaceous period dominant large predators northern hemisphere culminating gigantic fossils recovered continents north_america europe asia south_america australia characterized numerous skeletal features especially skull early existence small predators long late cretaceous genera larger including largest land based predators exist later genera small primitive feathers identified fossils species present prominent bony variety shapes sizes served display functions description varied widely size general trend increasing size time early small animals specimen fully grown measured meters length fully grown measured meters long teeth lower lower cretaceous rocks million years old japan appear come approximately metres long animal possibly indicating early size increase lineage immature meters length estimated meters long indicating genera reached larger sizes late cretaceous ranged meter exceeded meters length weighed kilograms short tons review literature concluded mid sized million years largest terrestrial live million years early long low lightly constructed similar later forms taller massive despite differences form certain skull features found known bone tall snout feature evolved nasal bones fused arched slightly upwards roughly upper surface teeth upper jaw shaped differently rest teeth smaller size shaped cross section lower jaw prominent ridge bone extends sideways jaw joint basal shaped long tails early genera long length typical long persisted early cretaceous unknown derived strongly reduced size extreme example quarter length digit reduced time digit basal slender functional hand preserved preserved specimens second digit hand largest digit present characteristic features include concave notch upper end sharply defined vertical ridge outside surface extending upwards hip huge boot end half long shaft features found known including basal members known typical characters like toes toe contact ground longer relative body size proportions characteristic fast running animals including elongated proportions persist largest adult despite probable inability run second fourth forming structure known present unclear found structure shared derived present basal like indicating evolution classification named henry family derived ancient greek words published paper british walker commonly animal derived greek form scientists commonly understood include immediate ancestors advent phylogenetic taxonomy clade received explicit definitions paul defined stem based taxon including species sharing recent common ancestor birds family exclusive thomas include species closely related published new definition external definition adopted review studies suggested clade usually considered basal authors disputed placement study hand anatomy published caused original scientists suggesting relationships partly reject prior conclusion species following taxa classified based latest studies animals late cretaceous eastern north_america late portugal late cretaceous new_jersey united_states early cretaceous southern england late cretaceous western mexico middle cretaceous early cretaceous central china family family family uncertain placement late cretaceous instead late cretaceous china late cretaceous new_jersey united_states synonymous species late cretaceous eastern north_america belong kind late cretaceous represent juvenile specimen instead phylogeny long recognized family ancestry subject debate twentieth century commonly accepted members included large group considered ancestral early 1990s analyses instead began place echoing suggestions published 1920s universally considered large grouped clade called based common ankle structure second fourth meet near bones covering viewed basal like found non indicating feature evolved dismantled longer usually considered basal outside recent analysis found family including late north american genera sister group basal known complete skeletal remains early taxa include known far complete material better known considered slightly derived long difficult genus classify turned recent analyses basal slightly related poorly known genus definitely exact relationships unclear taxa considered possible authors including early cretaceous thailand originally described early usually considered today vertical ridge reminiscent fact earliest known member material known sure includes virtually known species distribution lived split middle northern continents separated later era earliest recognized lived late including northwestern china western united_states portugal fossils currently referred instead belong given great similarities dinosaur portugal north_america time middle england fact earliest known genus suggest originated europe early cretaceous found northern continents england northeastern china named genera age early cretaceous teeth known cedar mountain formation utah group japan middle cretaceous fossils longer found europe suggesting localized extinction continent teeth possible body fossils known north american formation formations middle cretaceous remains occur stage late cretaceous north_america asia recognized known north_america found continents fossils found alaska served land bridge allowing dispersal continents non like possibly contemporaneous asia absent western north_america eastern north_america divided western interior middle cretaceous isolated western portion continent absence eastern continent suggests family evolved appearance allowing basal like survive east population end cretaceous basal present southeastern australia early cretaceous partial hip bone distinctive like form discovered dinosaur cove victoria indicating limited northern continents previously thought unnamed basin new_mexico found feathers long structures preserved skeletal remains numerous early cretaceous formation nearby geological formations china usually interpreted branched feathers found birds non proposed skeleton described included example feathers similarly feathers modern birds feathers found branched large found evidence feathers formation known specimens preserving traces feathers parts body areas body preserve impressions specimens fossils demonstrate medium sized species body covered feathers presence feathers basal surprising known characteristic found basal genera like derived groups rare skin impressions late cretaceous lack feathers instead showing skin covered fine non overlapping scales possible feathers present areas body preserved skin impressions small come primarily legs pelvic region underside tail alternatively secondary loss feathers large analogous similar loss hair largest modern mammals like elephants low surface area volume ratio heat transfer making coat hair unnecessary precedent seen dinosaur groups structures lost scales reappeared head bony found including numerous elaborate found nasal bones support single large crest runs skull crest penetrated large openings reduced weight prominent crest found low parallel ridges run skull supported nasal bones ridges curve meet nostrils making crest shaped fused rough possible bears single row prominent bony nasal bones similar row lower present skull specimens prominent horn eye bone horn absent instead crescent shaped crest eye bone head display species recognition courtship behavior example handicap principle case large delicate crest hunting presumably active predator individual healthy successful hunting despite fragile crest indicate superior quality individual smaller similarly tail male irish crest evolved sexual selection providing advantage courtship decrease hunting ability reproduction sized fossils documented scientific literature


meaning different branch genus late cretaceous period asia type species known partial skull foot bones recovered sediments deposited humid million years ago remains named described soviet second species known complete skeleton named described stephen colleagues relationships genera unclear evidence supporting hypothesis closely related contemporary species like known sharp teeth indicate known specimens smaller like adult size difficult estimate species known juvenile sub adult remains recent discovery indicates belongs distinct branch genus characterized row bony snout greater number teeth genus lower skull description estimated metres length originally described correct skull indicate shorter overall body length individual specimen juvenile adult reached greater lengths confirmed adult specimens known skull approximately centimetres long general long low shape typical basal juveniles larger bones tip snout found taller wide known nasal bones fused row irregular bony upwards nasal bones measure tall skull called crest arising fused bones feature shared crest greatly similarly like rest skull lower jaw long slender possible juvenile characteristic ridge outer surface angular bone lower jaw articulated rear bone locking bones removing flexibility seen teeth shaped cross section including teeth intermediate basal conditions rest skeleton completely unknown bones upper foot discovery known substantially complete remains shed light anatomy genus classification long classified remains years poorly known precise classification remained elusive discovery analysis published found classified family subfamily alongside study supported result suggested equally probable belonged outside family entirely supposed juvenile characters actually reflecting basal position study omitted altogether specimen nature discovery confirmed placement genus shared skull features including locking mechanism lower jaw angular bones lacked nasal bones connected bones adult genera closely related representing asian branch specimens row nasal bones like lower long low shape known skull indicated immature died juvenile lived time place prominent nasal higher tooth count suggested separate taxon known juvenile remains confirmed discovery specimens identified immature tooth count adults recently published finding outside discovery naming pin partial skull associated joint soviet expedition desert early 1970s found remains locality known province named described russian low skull profile looked different believed find far removed members family accordingly gave generic derived latin branch specific means removed latin known beds considered age formation formation dated fauna present fossil record indicate probably deposited stage end late cretaceous stage preserved formation characterized humid climate compared semi arid environment preserved earlier underlying formations sediments preserve large river channels soil deposits deposits indicate periodic environment supported diverse generally larger dinosaur fauna earlier times reported including discovered locality remains reported detail fauna similar formation present potential prey predators


meaning extinct genus dinosaur middle argentina found deposits formation date million years ago originally specimens assigned taxon belong different genus probably lived alongside genera unnamed known specimens including juvenile anatomy growth fairly understood ages exhibit typical features long neck small head long tail juvenile exhibits features different adult regions like pectoral overall anatomy similar known specimens help fill gaps anatomy genus skull parts skeleton like pectoral robust like material similar closely related taxa like primitive genera derived like discovery naming 1970s specimens previously unidentified found associated bed locality near route specimens described fossil erected genus type species generic comes location find fact specific honours land initial discovery genus originally known complete skeleton lacking skull referred specimens found species specimens probably taxon skeleton found near aged deposits formation completely known articulated specimens found covering skeleton including parts skull specimens referred species material probably unique taxon assigned specimens genus includes post skeleton known material nearly complete juvenile skeleton skull directly comparable type material confirms association genus specimen referred includes lower jaw similar differences associated age presumably represents adult material teeth different lower jaws identified deposit taxon certainly includes description possessed general having neck small head long tail similar related genera possessed morphology estimated long weighed long tons short tons earlier estimate john colleagues found approximately long metric tons short tons long tons weight similar later estimates study henderson calculated weight long tons short tons smaller estimate skull known revision oliver determining jaws certainly opposed nearly entire skull shows morphology adult skull like represents juvenile individual based broad high short adult articulated snout short high broad typical feature teeth reminiscent derived similar morphology concave having crowns fairly great expansions similar genus expansion teeth possess marginal denticles crown based studies individual replaced teeth days similar days days skeleton skeleton known caudal dorsal generally similar possesses distinct features preserved showing possessed fifth fused spines tall occasionally narrow canal unique starting end extending end canal forming defined cavity distinguishing ribs resemble total length total length pelvic preserved studied pelvic complete lacking ends known distinct features long straight expansion end upper edge blade curved thick rough spots attachment elements large robust adults juveniles flat viewed convex seen resembles comparing small expansion resemble resemble similar based material pedal bones come adult single additional bone known juvenile adult different juvenile cross section head preserved lacking greater end symmetrical viewed similarly sized surfaces juvenile fourth completely end developed crest short robust surface articulated life anterior half raised posterior half lowered pectoral known left right known incomplete large robust near blades flat convex anterior edge articulate gradually thinner gain distance younger specimen possesses slightly different morphology pectoral slightly differing proportions slightly smaller blade resemble shape differ directly compared based bones juvenile specimen manual elements preserved slender lacking great expansions incomplete crest shows wide likely projection like radius slender lacks large expansions end edge closest radius possesses ridge edge corresponds attached complete sediment filled breaks altered original shape different robust later like instead resembles classification originally described identified relative family distinguished similar genus features genus identified named paper features uniting genera identified pelvic structure specifically caudal spines characteristics genera derived primitive later paul published paper early finding found earlier works distinguished groups family relatives actually closer true noted work group reveal different conclusions revision wilson published joint analysis primitive relationships found fact sister taxon instead basal genus effectively results shown uncovered middle formation preserves large variety flora fauna fact noted fossil record formation represents completely known continental middle late southern hemisphere complete entire world formation deposited million years ago lush ecosystem organisms lived middle region great southern plants conifers abundant directly formation layer ash indicating nearby volcano fauna dominated ranging aquatic amphibians terrestrial turtles mammals sole known turtles represented distinct form named mammals known genera including multiple identified including potential genus unnamed include related


meaning volcano tooth extinct genus dinosaur early southern africa known species discovered known regarded earliest known decades primitive discovered ground dwelling showed typical body plan column like legs long neck tail smaller measuring approximately metres length known skeleton including pelvic hind limbs tail lacking trunk neck skull originally genus believed knife shaped teeth found near fossils fit idea scientists know teeth belonged unidentified known true discovery related animals unified family universally accepted etymology roman god fire tooth named michael points fact skeleton found small body sandstone lava flows emphasizes peculiar knife shaped teeth known belong species refers place discovery small island lake description small measuring approximately length earliest important understanding early evolution group descend basal informally called legged fully legged limb proportions intermediate ancestors later derived similar later basal straight end shaped unfortunately skull neck known known limbs column like long reaching length lower leg toes shortened comparison ancestors short later fused possessed tail bodies showed excavation lateral sides saving weight giving appearance viewed later excavations enlarged form extensive pockets called contrasting like features skeleton relatively primitive reminiscent ancestors feature shelf found derived toe foot showed large flattened seen claws second toe unusual nail like broader deep feature found probably closely related absent feet later contact ground derived feature found basal like retained primitive features like fact reduced features found basal lack related change body size greatest regions affected hind limbs example size reduction lesser shelf posture features indicate positioning leg muscles modified possessed features seen earliest reduced seen derived means muscle positioning legs changing reduced region limb classification originally michael described advanced specialized possibly family according like limb proportions independently evolved evolution argued primitive features knife shaped teeth classification teeth known belong arthur arguing fifth bone equally long remaining condition seen today universally accepted basal primitive members michael cooper erected new family regarded later families originally included indian subsequent studies attributed number early genera family including paul showed closely related later advanced rendering invalid exact relationships basal genera remain unclear colleagues found closely related newly discovered genus morocco researchers suggested clade containing sibling relationship confirmed analyses adam described single tail upper formation south_africa belong genus closely related upper formation famous abundant fossils discovery known single locality island lake largest artificial lake world northern island located west hills called island early unpublished lake charts formal bone found gibson town july excavation team collected specimen october march later half new find presented scientific cape_town brief note published find formally described july michael found skeleton catalogue number found hill slope partially eroded surface plant roots includes left hind limb foot right thigh bone anterior tail remains single individual found articulated connected additionally bones found including right right left probably pertaining individual later site revisited scientists bond michael cooper able collect additional remains including shoulder blade fragment neck remains individual present possible today remains stored natural history museum noted discovery teeth near pelvic region skeleton argued embedded head neck backwards posture called death pose frequently seen dinosaur skeletons teeth preserved elements skull shown cooper teeth dinosaur later lower southern africa scene massive resulting extensive lava flows called flood covered southern africa antarctica formations known large province comes beds fossil bearing sediment unit formation composed primarily flood skeleton found near thick layer flood long assumed lived earliest stage boundary approximately million years ago regarded earliest known discovery older late announced adam recently shown actually younger previously thought dating latest lower stage approximately million years ago contemporary closely related locality dated roughly contemporary entire sequence volcanic finished million years named dinosaur beds cooper noted habitat desert like indicated wind blown sands forest sandstone formation beds sediments found represent fan deposits desert landscape contained lakes wet season individual shores cut fan deposits transported locality found flooding initially thought mainly aquatic inhabiting lush swamps captive water support giant body weights cooper pointed primitive known time lived desert like environment terrestrial indicated large body size seen evolved adaptation aquatic life style


meaning family clade cretaceous period ancient southern today fossil remains found modern continents africa south_america indian island madagascar reports based isolated teeth occurrence late portugal confirmed existence european comes late cretaceous france appear fossil record early middle period species survived end era million years ago like characterized extensive ornamentation skull bones grooves pits like skull shorter bony grows eyes known meters length snout tip tail new unnamed specimen northwestern kenya africa reaching possible length meters feet known remains occasionally possible south american description typical upper ankle bones fused forming shorter giving proportions functional foot second fourth digit contact ground skull skull proportions varied generally tall short length example skull nearly tall long tall snout blunt tapered seen skull bones bones projected eye nearly dividing compartments eye located upper compartment slightly providing degree vision met eye form ridge eye seen skull bones form long grooves pits like frontal bones skull roof fused commonly bony projections skull pronounced horns projecting outward eyes close relative smaller projections area single bony horn dome projecting upwards skull projections like horns modern animals displayed species recognition intimidation dorsal margin probably forming strong bony ridge rising level skull roof maybe ridge supported structure displays hands data known small bones radius extremely short length upper arm entire arm held straight elbow joint typical hand basic similarity ends wrist bones existed palm bones directly finger bones fourth second digit digit external fingers extremely short manual claws small totally absent primitive relatives longer mobile arms fingers claws alexander suggested major reason evolution group genetic defect loss function genes regulate development distribution typically regarded cretaceous group earliest remains known middle argentina classified species possibly madagascar remains unnamed species possible remains isolated left right right discovered late beds remains mainly known southern continents described known late cretaceous south_america located late cretaceous india madagascar closely connected cretaceous thought absence continental africa indicated group evolved separation africa million years ago discovery material middle cretaceous northern africa hypothesis mid cretaceous known south_america showing group existed prior breakup description southern france provided evidence presence europe presents strong similarities indian south american forms indian forms united new clade classification coined described eponymous formed family discovered greek word meaning common usually applied family names derived greek indicates family rank based taxonomy contains family definitions phylogenetic taxonomy originally defined based taxon including common ancestor descendants later stem based taxon including animals closely related complete based definition include animals like thought basal included stem based definition united shared characteristics complete skeletons described advanced making difficult establish defining features skeleton family known skull bones known shared features come mainly skull skull features shared shared features fact replaced south_america led suggestions groups related analysis found relationship aside skull different similar respectively phylogeny generated description creation new subfamily originally described sister group tentatively places closer result agrees recent analyses stem based definition basal basal outside based definition adopted published included analysis independent analysis performed colleagues shows scientists include argentina india basal consider outside french called basal description published phylogenetic analysis focusing south american results found south american forms including grouped sub clade named year matthew scott published new large phylogenetic analysis description diego oliver combined analyses added new characters following follows analysis


extinct genus dinosaur lived approximately million years ago cretaceous period province china named china type species means chinese face location discovery medium sized built ground dwelling grow estimated length metres height weigh tonnes long tons short tons dinosaur discovered china known asia known fossils discovered north_america possibly significant largest known larger known basal members group discovered formation deposited late cretaceous lived alongside common creature formation material assigned animals living alongside etymology genus means chinese face derived word referring china latin country discovery greek words meaning horn meaning face described named colleagues type species specific refers location discovery city financed excavations description larger estimated length metres weight tonnes long tons short tons height metres thomas estimated length metres weight tonnes long tons short tons weight short hooked horn nose called nasal horn horns eyes horns short neck series forward curving gave crown like appearance inside row series low seen dinosaur member short specimen consists partial skull elements skull roof partial skull estimated long making largest known distinguishing features features differentiate animal called diagnosis features diagnosis distinctive feature unique given organism according distinguished based following characteristics robust strongly curved processes rear margin combined time processes combined present large differing known external margin weakly differing known presence broad based differing known discovery specimen consisting partial skull including summer recovered formation group china specimen collected sediments deposited stages cretaceous period approximately million years ago specimens recovered formation specimen partial skull consists skull roof represents partial discovery significant represented known china possibly asia possible asian recently identification questioned classification assigned taxon basal member based characteristics present skull bears characteristics resemble features distinction according basal position indicates originated asia shares number features advanced seen primitive like including developed nose horn reduced horns genus represents lineage invaded asia north_america follows phylogenetic analysis performed clade names follow known formation southern china known skull material alongside formation lived common material assigned asian related asian possible older individual possible remains assigned probable junior synonym material tentatively assigned


meaning near highest greek high large genus dinosaur similar appearance like tall hollow rounded crest large straight known remains species spanned million years ago late cretaceous alberta canada montana usa latest hollow known good remains north_america obscure genus discovery 1990s nests eggs belonging description easily distinguished hollow tall spines form crest spines project times height body respective given tall profile skull hollow crest like pointed tall wider small bony point rear unlike passages form curve crest animal estimated meters feet long weighed tonnes tons skeleton particularly remarkable pelvic details distinctive like known species differentiated typical method unique characteristics described transitional earlier later photographs adult skull animal looks similar classification recognized description skull closest jack suggesting transitional michael suggesting genus genera particularly regarded branch clade form informally designated found close relationship indicating rejected later comprehensive found species form clade closest relatives following illustrating relationships close relatives recovered phylogenetic analysis albert discovery history type remains remains collected brown american museum natural history remains partial skeleton consisting partial came red deer river near ferry alberta canada rocks known canyon formation early upper cretaceous brown described remains combination bones new genus considered like skull known time soon discovered described period remains small hollow described genera species figure history based skull limb bones pelvic bones canyon formation long richard wright identified american museum natural history skeleton medicine formation montana specimen taxa accepted valid genera 1970s peter showed likely juveniles established concerned earlier dinosaur park formation genera suggested turn composed juvenile individuals contemporaneous idea accepted formally tested medicine like specimens studied good reason like species named species type species known articulated associated skeletal remains juvenile adult individuals found canyon formation known unknown substantial number individuals age range embryos adults hypothesis form natural group excluding known species incorrect noted phylogenetic analysis found closely related rejected evans new species named variety remains including associated eggs nests found near late upper cretaceous medicine formation county montana border alberta represent largest collection baby skeletal material single species known shared canyon formation fellow variety poorly known small including formation known land age distinct formations canyon formation interpreted having significant marine influence western interior shallow sea covered north_america cretaceous preferred stay slightly older medicine formation home populated known nesting known nesting traces armored present formation distant western interior higher drier terrestrial influence eating variety plants skull 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 nests growth laid roughly spherical eggs embryos long long young individuals deep slight expansion bones day form crest growth faster comparable growth years based bone growth seen lines arrested growth analogous growth rings trees research lisa cooper colleagues indicates animal reached reproductive maturity age years reached size years old thigh bone reproductive maturity size growth rate predators rapidly growing better chance reach size large defensive value beginning reproduction early age prey animal secondary found skull specimen crest functions hollow crest likely social functions visual signal allowing individuals identify sex species providing chamber making noises crest associated nasal passages figured debate dinosaur specifically discussions nasal thin bones come types functions nasal found living function smell respiratory function prevent water loss found birds mammals modern warm animals lose great deal water breathing breathe sized cold animals support higher concluded respiratory probably present based scanning evidence animals warm discovery tooth marks specimen inflicted bite teeth indicated preyed large late cretaceous period examining oxygen ratio bones different parts extinct animal body indicate mode animal lifetime warm animal maintain similar body temperature entire body called little variation oxygen ratio measured different bones alternatively oxygen ratio differs considerably measured body organism cold physiology oxygen calculated suggesting varied little indicating likely contrast finding warm based absence nasal crest functions study processes organism body undergoes dies includes study preservation cause death circumstances burial large montana interpreted group killed volcanic considered meaning remains thought buried near spot individuals died variety ages group supports actual life animals cause death volcanic ash gases released volcanic preservation diverse group provides researchers growth series sequence growth stages juvenile adult


meaning crest genus large lived million years ago late cretaceous north_america asia genera known multiple continents distinguished spike like crest projects skull dinosaur type species described brown canadian fossils second valid species represented numerous specimens described description known material including nearly complete skeletons giving researchers clear picture bony anatomy species long skull long weight estimated tonnes tons species larger type skeleton roughly long larger remains reported aside size species virtually identical hindered lack study distinctive feature crest present young individuals smaller long spike like projects upward backward angle starting eyes crest described solid appears solid point internal chambers respiratory heat regulation function skull species described bell evaluated entire species publication description found skull larger unusual feature long protruding solid crest extends upwards skull roof unlike completely nasal bone bones entire skull length sides filled small holes adult individuals contact fused longer nasal bones longest skull entire length crest preserved fused classification brown described specimens subfamily time included known examples brown thought expanded tip bone hip recognized appears based mistakenly associated additionally bones publications classified member known colloquially flat headed subfamily brought use appears branched prior split result definition include traditional oldest available clade suggests largely solid crest following relationships published discovery history brown recovered described remains including nearly complete skeleton display american museum natural history skeleton nearly complete dinosaur skeleton canada found rocks early age upper cretaceous canyon formation known formation near ferry red deer river alberta brown wasted little time describing material giving subfamily important early reference seen names near little additional material recovered described instead abundant remains asia provided data initial remains promising partial china named better remains soon recovered early age formation russian expeditions recovered large skeleton described skeletons variety growth stages discovered abundant asian partial skeletons found late age formation california specimens referred instead assigned placed specimens new species species reassigned new genus species species regarded valid today type species brown known skull skeleton complete skull fragments known specimens differs details skull pattern scales found skin impressions species longer skull snout bones directed distinctive row square scales tail smooth scales tail flank arranged vertical patterns corresponded striped coloration life area covered radial scale patterns possibly indicating spotted coloration considered valid regarded dubious synonym species bell described unique derived traits established distinguishing bell found publication earlier year previous studies provide comprehensive description compare species known upper unit canyon formation lived alongside dinosaur species including unnamed species small including formation form land age canyon formation interpreted having significant marine influence western interior shallow sea covered north_america cretaceous preferred stay inland study suggested distinct inland fauna characterized association contemporary coastal fauna characterized association association later noted error occurs lower canyon formation major western interior represented marine tongue largest formation lacked large diverse fauna rare flat headed large rare types including including relative unlike formations like known formation includes interpreted like dinosaur park formation alberta examined rock formation suggest presence stream river channels shallow lakes sediments indicate rich habitat existed offering diverse food abundant amounts sustain cretaceous eating variety plants skull 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 common important large formation rare canyon formation faced competition genus comparisons rings modern birds reptiles suggest active day short intervals crest distinctive spike like crest interpreted multiple ways multiple functions brown compared crest suggested provide area muscle attachment connection point like seen peter interpreted similar features having use sexual identification noting hollow base suggested crest increased surface area respiratory cavity helped james supported function visual signal mentioned possibility skin flaps nostrils acted additional visual signals idea picked authors popular dinosaur works david norman discussed display length included life restoration adaptation action unique crest completely nasal bones solid adult specimens rounded triangular shape cross section crest past edge skull backwards thin processes extend underside crest probably strengthen end crest swelling nasal termed differently growth rates poorly understood group recently discovered area desert known dragon tomb animals uncovered skull lengths percent length adults indicating earliest developmental stage time deaths discovery indicates distinct crest found adults poorly developed infancy remains unknown animals eggs hatched died specimens described journal october


genus dinosaur known fossils uncovered modern day portugal represent species species described material formation precise age formation known dated early late known material includes dorsal ribs fragment material ribs general distinguish material described genus differences noticed material new specimen thought known portuguese means lived alongside relative closest relative form clade primitive considered likely basal discovery naming uncovered associated excavations lasted time discovery specimen moved museum number announced soon excavations complete remove fossils surrounding rock tilt hammer needed fossils situated cliff removed shipped blocks help crane year described new taxon assigned previously grouped studied material concluding specimen closely related morrison formation new new species described meaning material included ribs partial certainly dorsal regions articulated greatly preserved articulated good condition material includes seven arches dorsal ribs preserved elements david recognize material belonging found limb fragment incorrectly stated found formation pair collection number originally assigned considered distinct new unnamed genus description average sized elongated neck tail main features genus based anatomy multiple spine found total approximate length known non material currently consisting partial ribs fragment ribs attached elongated feature distortion set ribs ribs left animal shaped cross section display features incomplete state makes identification uncertain multiple right ribs preserved including shafts heads similar left ribs lack non material includes incomplete shaft displays practically features described detail distinguishing material comes represented described assumed preserved according number apparently lost excavation removal specimen original description thirteenth prepared portion length fourteenth similar overall total measurement 14th preserved complete concave edge spine compressed compared massive projects upwards posterior end relatively complete series dorsal known number seven distorted upwards state preservation noted position certain fact dorsal second dorsal similar numbering found second similar anatomy second dorsal vary length dorsal seventh ninth height variable shortest height tall tall increasing dorsal classification extremely known consequence phylogenetic position certain taxon philip recovered sister species forming basal published modified matrix found primitive derived found group supported fact primitive outside considered species new combination results shown previously classified excluding differences great found features present suggested derived features present conclude branched separately descendant study found intermediate probable possessed whip tail likely tail like speed related probably possessed squared snout means probably non selective ground feeding relatively found obviously alongside type specimen experiment tested style mill analysis took account hundreds found known associated specimens authors chose use associated large found birds birds typically found body weight highest amassed body weight means body mass style mill unlikely evolved instead absorb minerals lived formation late especially formation contains similar fauna north american morrison formation known including unnamed genus intermediate common intermediate known represented identified remains including found late europe base based presence currently based unnamed specimen including bones clearly different confirming presence possibly late spain portugal unique variety europe genera possibly non classified suggests primitive incomplete possible primitive surviving late potentially


meaning vine dinosaur late cretaceous period europe type species named possible unnamed species given age reaching latest cretaceous million years ago like long neck tail carried armor form bones assigned assigned assigned assigned species differences limb proportions linked individual variation known preserved teeth material right discovered associated blade contrary triangular blade narrows end instead showing expansion like genera known centimetres long aside known partial group cretaceous times spanish locality latest cretaceous yielded relatively preserved shares number unique features france appeared differ traits specimen identified likely mature bones largely fused lived alongside animals specimens found alongside including plants invertebrates sierra saint formations recent attention known known france description like long neck tail carried armor form centimetres long found different plate spine shaped dinosaur stretched metres snout tail known bones teeth best known france considered dwarf smaller size comparison ancestors skeleton completely known europe bones discovered upper cretaceous locality southern france assigned abundant preserved elements uncovered original description tooth examined complete description known material allowing better understood material assigned species differences limb proportions linked individual variation known preserved teeth material tooth described original description teeth differentiate europe teeth different later genera teeth roughly cylindrical thin expansions millimetres high millimetres wide expansions teeth slight root crown teeth different like teeth teeth general morphology similar skull described southern france showed differences meaning different france late cretaceous found attached longer direction bone centimetres long blade contrary triangular larger closer base blade narrows instead showing expansion differing dorsal crest base blade shape margin known centimetres long strong expansion similar brazil large contrary south american expansion known shaft developed flat incomplete radius known lacks ends possesses prominent ridge largest best preserved specimens right total length millimetres right small slender missing marked ridge left larger length millimetres deep radial known making common bone complete flat lack unusual features study bone physiology found maximum known length millimetres larger previously known millimetres means ancestors slightly smaller known approach size largest free cavity robust centimetres long expanded ends different types recovered large spines uncovered base spine centimetres tall large internal faces convex ridge opposite spine view sections low half progressively spine specimen group connected dorsal uncommon poorly preserved rear spines preserved face rear dorsal preserved complete crushed arch spine characteristic shape widened narrows downwards internal structure large cells caudal strongly compressed sides spines caudal narrow tall point rear middle caudal compressed sides middle caudal longer known poorly preserved thought belong juvenile complete found distinguishing features set characters identified description distinguish genera teeth weakly widening spines dorsal arch dorsal strongly rear lack expansion blade presence light ventral crest presence plate spine shaped added spine dorsal probably characteristic fossil tentatively assigned unnamed species article journal found share features skull flat small size overall length millimetres maximum width left half millimetres parts half missing section missing specimen appear deformed left right halves different preserved millimetres long millimetres wide upper surface frontal smooth crest runs frontal roof found connection marked shaped crest viewed extensions extensions fully preserved border upper temporal middle preserved millimetres wide specimen unique wider tall irregular surface probably caused loss original covering complete especially low skull oriented millimetres wide millimetres tall floor tall long bone length millimetres compared inner ear shows basal morphology feature possibly related restricted range possible movements involve head turning like non relatively poorly preserved contrast taxa characteristic seen brain especially narrow cerebral region brain separated rest brain distinct compression caused cavity cerebral region small expansion different relatively larger expansions known small opening skull roof middle responsible swelling suggestive system exact position expected canals contracted highly curved system shows basal morphology canals attach discovery naming originally found near sur france recovered lower levels formation belong early late cretaceous period million years ago sediments represent ancient numerous river channels french jean described named dinosaur derived greek latin means located south region found specific based latin river remains found discovered produced numerous ribs tail limb bones skull material aside tooth different sizes shapes recovered material comes different individuals material uncovered region france including relatively complete skeleton elements skull lower jaw later sur site explored time jean years searching uncovered complete skeleton contained material including bones unknown material went des took years assemble discovered found course construction high speed rail track connecting madrid fossil site animals found sierra formation site locality named near village spain course months large scale emergency excavation manual workers allowed thousands specimens plants invertebrates late early age saved including classification characteristics tail presence indicate belongs group derived includes classified belonging uncertain classification clearly features found placing derived growth grown way similar basal certain point development microscopic material bone different basal grew slowly bone unique basal increase bone growth decrease growth rate presumed onset sexual maturity gradual process growing started sexual maturity clearly delayed period growth sexual maturity shortened dominated slow bone building instead fast growth growth marks generally rare appearing late lack growth marks suggestive fast continuous growth supports hypothesis achieved large body size fast growth growth marks bone sample unusual found apparently reduced growth rate high level bone growth seen features associated occurrence growth marks system found surface bones thought growth plateau indicates maximum body size skeletal maturity reached individual known found non closely related related basal found lacked basal shown likely outer edge bones found preserved lacked proof present study found lack larger specimens tested characteristic basal majority specimens found secondary placed densely inner regions bones lightly outer regions orientation found facing bone typical cavity bones stages life based bone known specimen formation specifically known layer produced fossils produced formation elements plants invertebrates consist numerous remains scales shell fragments turtle fragments teeth isolated teeth classified elements bird dinosaur eggs recovered formation known saint dinosaur eggs previously known possible known formation known formation fossils formation belong sierra formation latest cretaceous aged region sierra formation study shows area dates late early recent study revised later date latest study showed near coast sea large southern europe northern africa area directly coast shown freshwater aquatic environment muddy flood plain found inside flood plain flood plain found channels sand material different found largest remains articulated individuals caudal teeth caudal identified closely related differences teeth assigned apart sierra formation good representation plants known branches leaves invertebrates fishes formation include plenty material unidentified turtle fossils common common fishes material different groups identified uncommon known specimens known specimen similarities common consist material basal probable known remains consist known formation known fair elements identified group cretaceous times fossils found continents remains abundant number late cretaceous sites nonetheless anatomy poorly known best known europe include hungary unnamed species spain numerous fragments isolated bones belong forms found southern continents derived species known sediments northern hemisphere including north_america asia indicating intermittent connections northern southern continents european find late cretaceous dinosaur similar known southern continents distinct known number late cretaceous european archipelago found date limited shows significant diversity specimen resembles


intended meaning limb greek meaning rib beef meaning genus armoured dinosaur england lived early period stages million years ago genus related genera time lived fossils found near england known excellent preservation called earliest complete dinosaur completely known dinosaur british isles despite modern description lacking initial finds 1850s comparative richard owen named described species named owen considered valid today species proposed metres long largely animal feeding low plants parts small elongated head processed large gut lightly armoured protected long horizontal rows oval stretched neck tail oldest known primitive exact placement group subject debate nearly years helped limited additional knowledge early evolution armoured today evidence indicates basal member basal ancestral advanced description size posture grown small compared later non medium sized species early scientists estimated length metres gregory paul gave body length metres weight longer hind legs foliage trees arms relatively long indicating posture skull head small centimetres long elongated skull low view triangular view longer wide similar earlier snout largely formed nasal bones flat pairs skull openings seen basal apart nostrils eye present basal upper lower temporal closed later armoured forms fact upper temporal large forming conspicuous round openings rear skull serving attachment areas powerful muscles closed lower jaws eye slightly overshadowed bone upper rim eye formed bone study concluded juvenile specimens bone fusion elements rear inner bone forming snout tip short bone core lower tip stout lower jaws found assumed present likely short teeth longer triangular view later armoured teeth nineteen sixteen lower jaw number teeth established incomplete skull specimens found actual numbers ranged dozen teeth somewhat longer rear gradually approach form teeth beginning denticles crowns teeth denticles edges swollen basis skeleton column contained neck seventeen dorsal thirty tail actual total high seven neck moderately long relatively flat view despite belly broad extremely vertically compressed taller wide dorsal ribs spines touched fused plate quickly tapering tail relatively short probably representing half body length tail strongly inclined rear hip area tail base large numbers short moderately expanded upper end circular view elements generally moderately long straight stout hand known recent discoveries described wide straight view blade rod shaped moderately outside creating room belly reinforced ribs longer ribs wider attachment areas fused featured short shaft straight running parallel straight shaft flattened lower end straight view view somewhat outside head separated shaft real neck major level head lower minor separated deep rear mid shaft featured developed fourth process attachment tail muscle lower leg somewhat shorter wide upper end crest protruding lower end robust rotated compared upper turning foot strongly outside foot large wide fifth rudimentary robust large toes digit smallest fourth short toe long built outside foot improve stability claws flat shaped curved inside armour obvious feature armour consisting bony embedded skin arranged horizontal parallel rows animal body today found skin ranged size shape smaller larger oval plates high keel outside highest point keel positioned rear small flat inside larger aligned regular horizontal rows rows lowest lateral row conical blade like main series rows smaller oval present total rows large tail underside tail tail continued neck unknown unlikely neck pictured way neck rows large lower neck row large flat plate like neck rows formed pair unique pointed directly head points connected rear joint processes axis general larger diminishing rear especially surface smallest flat round filled room larger rows row vertical present upper arms compared later lightly armoured continuous plating spikes pelvic shield rough areas skull lower jaws indicate presence skin latest specimens found partly different including keel like spike specimens little horns rear corners head placed bones skin impressions found bony rounded non overlapping scales like present monster large small millimetres flat bone distributed skin later small developed larger multi plate armour seen genera history discovery 1850s quarry owner james harrison west england found fossils cliffs black possibly raw material manufacture cement gave collector retired general surgeon henry harrison sent limb bones professor richard owen british museum natural history london today natural history museum left specimen owen named genus entry text contained diagnosis genus named despite fact definition vague specimens identified owen intended dinosaur confused greek word rib beef inspired strong development hind leg harrison sent knee joint juvenile specimen skull owen described occasion type species named specific harrison skull later revealed nearly complete skeleton described owen british david bruce norman stressed remarkable owen previously active animals largely neglected serve prime example hypothesis fossil complete found time norman explained owen excessive workload period including administrative functions fellow scientists study large number interesting newly discovered extinct animals norman pointed owen suggested lifestyle different present ideas fish partially sea dwelling owen indicated richard fossils designated fragments described specimen consisting lower upper forming knee joint type specimen choosing gave reason choice motivated larger size unfortunately mixed fossils partial remains dinosaur belonged discovered bernard newman year newman suggested selection knee joint officially rescinded international commission nomenclature joint opinion species related eventually newman died jack actually filed request reacted positively opinion deciding skull skeleton specimen knee joint samuel informally assigned published likely belongs member established newman confirmed roger original left belonged skeleton uncovered black bed marine deposits formation dating late stage million years ago consists complete skeleton skull lower jaws snout tip neck base tail end missing hundreds found connection skeleton original position 1960s onward fossil prepared acid free bones surrounding matrix method perfected fossils reported single block treated died results published norman intends complete task revealed new details apart modern description largely lacking apart fossils known large number single bones largely limb elements acquired collection owen described second partial skeleton juvenile animal later added collection elizabeth today registered museum specimen relatively large owen speculated context presumed marine lifestyle short specimen convinced scientists process represent main body thought unable believe thin backward pointing forward pointing larger bone groups recent times new discoveries commercial efforts amateur second partial juvenile skeleton described specimen reported slightly younger layer member dating early million years old simon david peter excavated partial skeleton including complete skull skin impressions sold bristol museum registered specimen specimen collection museum cambridge specimens remain private collections include metres long skeleton found david sole complete non dinosaur discovered british isles elements skeleton known finds sole differ details armour represent separate taxon reflect sexual species named described owen currently recognized species based nearly complete skeletons potential second species age lower formation described david jay genus lucas moved fossils accepted today recognized found formation canyon group northern arizona kevin referred determine age strata million years ago time thought dated early established geographic tie arizona canyon europe fossils previously discovered later scientists rejected assignment different form roman named new species based specimens peter kenneth carpenter identified instead placing specimens david announced preservation soft tissue specimen referred unnamed species comparison fossil inventory number early 1990s prepared state discovered legacy late professor john illustrate lectures unknown consists series caudal cut slab judged date late stages parts fossil preserved way envelope preserved soft tissue visible presence layer authors concluded basal armoured covered tough probably layer skin classification phylogeny owen placed edward cope proposed family double lecture published december thomas henry named nineteenth century armoured dinosaur known considered member later twentieth century term assembly primitive close ancestry today usually consider forming separate branch clade lists group family resurrected chinese study shares close oldest known description twentieth century classified different times alfred von william robert identified genus concept encompassed armoured forms paper argued richard university queensland attempted similar argued lightly built dinosaur adapted running theories genus rejected debate ongoing time considered closely related extension true basal split classification fallen favor seen older dinosaur books analyses invariably recovered basal position outside position according study shown fossil records basal sparse primitive found arizona earlier genus possible early armoured dinosaur million years ago found france ancestors basal evolved early similar late diet like later groups possessed teeth capable grinding plant material smaller complex leaf shaped teeth suitable vegetation jaws capable vertical movement short jaw joint paul concluded fed crush system tooth tooth action precise simple jaw movement food inner upper teeth outer lower teeth teeth actually touching shown long vertical wear lower teeth aspect resembled bore primitive teeth simple jaws diet consisted conifers grasses evolve late cretaceous period long extinct similarity narrow head indicate selective diet consisting high quality fodder pointed animal size large gut allowing efficient intake easily food high energetic value important smaller animals critically dependent norman concluded fed low vegetation height metre raising vertically increased feeding envelope possible norman doubted relevant behaviour