JurassicFrom Wikipedia, the free encyclopediaThis article is about the geologic period andsystem. For other uses, see Jurassic Park(disambiguation) .The Jurassic (/d u rs k/ ! from Jura"ountains) is a geologic period and systemthat e#tends from $%&.'( %.) "a (millionyears ago) to &*+( * "a! from the end ofthe Triassic to the beginning of the ,retaceous. The Jurassic constitutes themiddle period of the "eso-oic .ra, alsokno/n as the 0ge of 1eptiles. The start ofthe period is marked by the ma2or Triassic3Jurassic e#tinction e4ent. T/o other e#tinction e4ents occurred during theperiod5 the 6ate Pliensbachian/.arlyToarcian e4ent in the .arly Jurassic, andthe 6ate Tithonian e4ent at the end!ho/e4er, neither e4ent ranks among the78ig Fi4e7 mass e#tinctions. The Jurassic isnamed after the Jura "ountains /ithin the .uropean 0lps, /here limestone strata fromthe period /ere first identified. 8y thebeginning of the Jurassic, the supercontinent Pangaea had begun rifting into t/o landmasses, 6aurasia to the north and 9ond/ana to the south. This created more coastlines and shifted the continental climate from dry to humid, and many of the arid deserts of the Triassic /ere replacedby lush rainforests. :n land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds also appeared during the Jurassic, ha4ing e4ol4ed from a branch of theropod dinosaurs. :ther ma2or e4ents include the appearance of the earliest li-ards, and the e4olution of therian mammals, including primiti4e placentals. ,rocodilians made the transition from a terrestrial to an a;uatic mode of life. The oceans /ere inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, /hile pterosaurs /ere the dominant flying 4ertebrates.Contents & .tymology $ inemurianPliensbachianToarcian0alenian8a2ocian8athonian,allo4ian:#fordian?immeridgianTithonian 0n appro#imate timescale of key Jurassic e4ents.Lertical a#is5 millions of years ago.The Jurassic period is di4ided into the .arly Jurassic, "iddle, and 6ate Jurassic epochs. The Jurassic >ystem, in stratigraphy, is di4ided into the 6o/er Jurassic, "iddle, and Mpper Jurassic series of rock formations, also kno/n as Lias, Dogger and Malm in .urope.BDC The separation of the term Jurassic into three sections goes back to 6eopold 4on 8uch.BEC The faunal stages from youngest to oldest are5Upper/Late JurassicTithonian (&+$.& ( * 3 &*+ ( * "ya)?immeridgian (&+E.' ( * 3 &+$.& ( * "ya):#fordian (&)'.+ ( * 3 &+E.' ( * "ya)Middle Jurassic,allo4ian (&)).& ( * 3 &)'.+ ( * "ya)8athonian (&)H.' ( '.+ 3 &)).& ( * "ya)8a2ocian (&E%.' ( ' 3 &)H.' ( '.+ "ya)0alenian (&E*.& ( $ 3 &E%.' ( ' "ya)Loer/Early JurassicToarcian (&H$.E ( &.+ 3 &E*.& ( $ "ya)Pliensbachian (&D%.H ( &.+ 3 &H$.E ( &.+ "ya)>inemurian (&DD.' ( & 3 &D%.H ( &.+ "ya)Iettangian ($%&.' ( %.) 3 &DD.' ( & "ya)Larious dinosaurs roamed forests of similarly large conifers during the Jurassic period.Paleogeography and tectonicsouth 0tlantic did not open until the follo/ing ,retaceous period, /hen 9ond/ana itself rifted apart.B&%C The Tethys >ea closed, and the @eotethys basin appeared. ,limates /ere /arm, /ith no e4idence of glaciation. 0s in theTriassic, there /as apparently no land near either pole, and no e#tensi4e ice caps e#isted.The Jurassic geological record is good in /estern .urope, /here e#tensi4e marine se;uences indicate a time /hen much of the continent /as submerged under shallo/ tropical seas! famous locales include the Jurassic ,oast World Ieritage >ite in southern .ngland and the reno/ned lateJurassic lagersttten of Iol-maden and >olnhofen in 9ermany.B&&C Pn contrast, the @orth 0merican Jurassic record is the poorest of the "eso-oic, /ith fe/ outcrops at the surface.B&$C Though the epicontinental >undance >ea left marine deposits in parts of the northern plains of the Mnited >tates and ,anada during the late Jurassic, most e#posed sediments from this period are continental, such as the allu4ial deposits of the "orrison Formation.The Jurassic /as a time of calcite sea geochemistry in /hich lo/Fmagnesium calcite /as the primary inorganic marine precipitate of calcium carbonate. ,arbonate hardgrounds /ere thus 4ery common, along /ith calcitic ooids, calcitic cements, and in4ertebrate faunas /ith dominantly calcitic skeletons (>tanley and Iardie, &DDH, &DDD).The first of se4eral massi4e batholiths /ere emplaced in the northern ,ordillera beginning in the midFJurassic, marking the @e4adan orogeny.B&'C Pmportant Jurassic e#posures are also found in 1ussia, Pndia, >outh 0merica, Japan, 0ustralasia and the Mnited ?ingdom.Pn 0frica, .arly Jurassic strata are distributed in a similar fashion to 6ate Triassic beds, /ith more common outcrops in the south and less common fossil beds /hich are predominated by tracks to the north.B&*C 0s the Jurassic proceeded, larger and more iconic groups of dinosaurs like sauropods and ornithopods proliferated in 0frica.B&*C "iddle Jurassic strata are neither /ell represented nor /ell studied in 0frica.B&*C 6ate Jurassic strata are also poorly represented apart from the spectacular Tendeguru fauna in Tan-ania.B&*C The 6ate Jurassic life of Tendeguru is 4ery similar to that found in /estern @orth 0mericaNs "orrison Formation.B&*CJurassic limestones and marls (the "atmor Formation) in southern Psrael.The late Jurassic "orrison Formation in ,olorado is one of the most fertile sources of dinosaur fossils in @orth 0merica.Gigandipus, a dinosaur footprint in the 6o/er Jurassic "oena4e Formation at the >t. 9eorge auerstoffgehaltF&%%%m2.s4g Pmage5Phanero-oic ,arbon tuttgart, (9ermany)5 ,otta, &H+H), p. )'$. From p. )'$5 0"c atte mic au4 einer geognostiscen 7eise, die ic 1895 durc das s:dlice 2ran/en, die 3estlice )c3ei. and ;+er5"talien macte, da'on :+er.eugt, da< der Jura56al/stein, 3elcen =erner .u seinem Muscel/al/ recnete, eine eigne 2ormation +ildete. "n meiner )cri4t :+er die unterirdiscen Gasarten, 3elce mein %ruder =ilelm 'on >um+oldt 1899 3rend meines $u4entalts in ):dameri/a erausga+, 3ird der 2ormation, die ic 'orlu4ig mit dem -amen Jura56al/stein +e.eicnete, .uerst ?). 39@ gedact.0 (:n a geological tour that P made in &ED+ through southern France, /estern >/it-erland and upper Ptaly, P con4inced myself that the Jura limestone, /hich Werner included in his shell limestone, constituted a separate formation. Pn my paper about subterranean types of gases, /hich my brother Wilhelm 4on Iumboldt published in &EDD during my stay in >outh 0merica, the formation, /hich P pro4isionally designated /ith the name 7Jura limestone7, is first concei4ed (p. 'D).) IRlder, I. &D)*. Jura K Iandbuch der stratigraphischen 9eologie, PL. An/e5Berlag, )%' pp., &+H figs, *' tabs! >tuttgart 0rkell, W.J. &D+). Jurassic 9eology of the World. ;li'er C %oyd, H%) pp.! .dinburgh und6ondon. PieSko/ski, 9.! >chudack, "...! 8osTk, P.! .nay, 1.! FeldmanF:ls-e/ska, 0.! 9olonka,J.! 9uto/ski, J.! Ierngreen, 9.F.W.! Jordan, P.! ?robicki, ".! 6athuiliere, 8.! 6einfelder, 1.1.! "ichalUk, J.! "Rnnig, ..! @oeF@ygaard, @.! PTlfy, J.! Pint, 0.! 1asser, ".W.! 1eisdorf, 0.9.! >chmid, ch/eigert, 9.! >urlyk, F.! Wet-el, 0. V Theo .. Wong, T... $%%H. Jurassic. Pn5 "c,ann, T. (ed.)5 The 9eology of ,entral .urope. Lolume $5 "eso-oic and ,eno-oic, Geological )ociety, pp.5 H$'FD$$! 6ondon. 1ollier, 6. &D%'. ch/ei-erische Juragebirge. )ondera+druc/ aus dem Geograpiscen Le(i/on der )c3ei., Berlag 'on Ge+r. $ttinger, 'D pp! @euenburg ?a-le4, ". 0lan ($%%$) Palaeos /ebsite 0ccessed July. $$, $%%H 6ate Jurassic Jurassic Period map "onroe and Wicander, )%E. Jacobs, 6ouis, 6. (&DDE). 70frican chneider, JRrg W.! >ch/ermann, 6eonie! >un, 9e! Whou,,hangFFu! Joyce, Walter 9. ($%&$), 70n enormous Jurassic turtle bone bed from the Turpan 8asin of Xin2iang, ,hina7, -atur3issensca4tenD &e )cience o4 -ature ''(, 8ibcode5$%&$@W.....DD..D$+W, doi5&%.&%%E/s%%&&*F%&$F%DE*F+ 9annon, "egan (:ctober '&, $%&$), 7Jurassic turtle gra4eyard found in ,hina7, Li'escience.com Linn, :.! "ut4ei, I. ($%%D). 7,alcareous tube/orms of the Phanero-oic7 (Pistory. @e/ Oork5 8@ %FEHD*F+&HEF+. Feduccia, 0. (&DD)). &e ;rigin and A'olution o4 %irds. @e/ Ia4en5 Oale Mni4ersity Press. P>8@ %F'%%F%)*)%FH. ,arroll, 1. 6. (&DHH). Berte+rate !aleontology and A'olution. @e/ Oork5 WI Freeman. P>8@ %FE&)EF&H$$FE. Iaines, $%%%. 8ehrensmeyer et al., &DD$, '*D. 8ehrensmeyer et al., &DD$, '+$ &. 8ehrensmeyer et al., &DD$, '+'-e.erences 8ehrensmeyer, ., and 1eed Wicander. (&DDE) &e #anging AartD A(ploring Geology and A'olution, $nd ed. 8elmont5 West Publishing ,ompany, &DDE. P>8@ %F'&*F%D+EEF$. :gg, Jim! June, $%%*, ;'er'ie3 o4 Glo+al %oundary )tratotype )ections and !oints ?G))!Es@, Pnternational ,ommission on >tratigraphy, pp. &E >tanley, >.". and Iardie, 6.0. (&DDH). 7>ecular oscillations in the carbonate mineralogy of reefFbuilding and sedimentFproducing organisms dri4en by tectonically forced shifts insea/ater chemistry7. Palaeogeography, Palaeoclimatology, Palaeoecology &**5 '3&D. >tanley, >.". and Iardie, 6.0. (&DDD). 7Iypercalcification! paleontology links plate tectonics and geochemistry to sedimentology7. 9>0 Today D5 &3E. Taylor, P.imple .nglish >lo4enina >lo4enwina hjkt / srpski >rpskohr4atski / jhjkhogmjkt >uomi >4enska Tagalog gmghg/tatara Trke khg-jkg Ting Lit OorbT .dit links This page /as last modified on && July $%&+, at &E5&%. Te#t is a4ailable under the ,reati4e ,ommons 0ttributionF>hare0like 6icense! additionalterms may apply. 8y using this site, you agree to the Terms of Mse and Pri4acy Policy. 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